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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * kernel/sched.c
3 *
4 * Kernel scheduler and related syscalls
5 *
6 * Copyright (C) 1991-2002 Linus Torvalds
7 *
8 * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and
9 * make semaphores SMP safe
10 * 1998-11-19 Implemented schedule_timeout() and related stuff
11 * by Andrea Arcangeli
12 * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
13 * hybrid priority-list and round-robin design with
14 * an array-switch method of distributing timeslices
15 * and per-CPU runqueues. Cleanups and useful suggestions
16 * by Davide Libenzi, preemptible kernel bits by Robert Love.
17 * 2003-09-03 Interactivity tuning by Con Kolivas.
18 * 2004-04-02 Scheduler domains code by Nick Piggin
Ingo Molnarc31f2e82007-07-09 18:52:01 +020019 * 2007-04-15 Work begun on replacing all interactivity tuning with a
20 * fair scheduling design by Con Kolivas.
21 * 2007-05-05 Load balancing (smp-nice) and other improvements
22 * by Peter Williams
23 * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
24 * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
Ingo Molnarb9131762008-01-25 21:08:19 +010025 * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
26 * Thomas Gleixner, Mike Kravetz
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 */
28
29#include <linux/mm.h>
30#include <linux/module.h>
31#include <linux/nmi.h>
32#include <linux/init.h>
Ingo Molnardff06c12007-07-09 18:52:00 +020033#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/highmem.h>
35#include <linux/smp_lock.h>
36#include <asm/mmu_context.h>
37#include <linux/interrupt.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080038#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <linux/completion.h>
40#include <linux/kernel_stat.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070041#include <linux/debug_locks.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <linux/security.h>
43#include <linux/notifier.h>
44#include <linux/profile.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080045#include <linux/freezer.h>
akpm@osdl.org198e2f12006-01-12 01:05:30 -080046#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/blkdev.h>
48#include <linux/delay.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070049#include <linux/pid_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <linux/smp.h>
51#include <linux/threads.h>
52#include <linux/timer.h>
53#include <linux/rcupdate.h>
54#include <linux/cpu.h>
55#include <linux/cpuset.h>
56#include <linux/percpu.h>
57#include <linux/kthread.h>
58#include <linux/seq_file.h>
Nick Piggine692ab52007-07-26 13:40:43 +020059#include <linux/sysctl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070060#include <linux/syscalls.h>
61#include <linux/times.h>
Jay Lan8f0ab512006-09-30 23:28:59 -070062#include <linux/tsacct_kern.h>
bibo maoc6fd91f2006-03-26 01:38:20 -080063#include <linux/kprobes.h>
Shailabh Nagar0ff92242006-07-14 00:24:37 -070064#include <linux/delayacct.h>
Eric Dumazet5517d862007-05-08 00:32:57 -070065#include <linux/reciprocal_div.h>
Ingo Molnardff06c12007-07-09 18:52:00 +020066#include <linux/unistd.h>
Jens Axboef5ff8422007-09-21 09:19:54 +020067#include <linux/pagemap.h>
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +010068#include <linux/hrtimer.h>
Reynes Philippe30914a52008-03-17 16:19:05 -070069#include <linux/tick.h>
Mike Travis434d53b2008-04-04 18:11:04 -070070#include <linux/bootmem.h>
Peter Zijlstraf00b45c2008-04-19 19:45:00 +020071#include <linux/debugfs.h>
72#include <linux/ctype.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Eric Dumazet5517d862007-05-08 00:32:57 -070074#include <asm/tlb.h>
Satyam Sharma838225b2007-10-24 18:23:50 +020075#include <asm/irq_regs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
Gregory Haskins6e0534f2008-05-12 21:21:01 +020077#include "sched_cpupri.h"
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079/*
80 * Convert user-nice values [ -20 ... 0 ... 19 ]
81 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
82 * and back.
83 */
84#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
85#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
86#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
87
88/*
89 * 'User priority' is the nice value converted to something we
90 * can work with better when scaling various scheduler parameters,
91 * it's a [ 0 ... 39 ] range.
92 */
93#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
94#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
95#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
96
97/*
Ingo Molnard7876a02008-01-25 21:08:19 +010098 * Helpers for converting nanosecond timing to jiffy resolution
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 */
Eric Dumazetd6322fa2007-11-09 22:39:38 +0100100#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200102#define NICE_0_LOAD SCHED_LOAD_SCALE
103#define NICE_0_SHIFT SCHED_LOAD_SHIFT
104
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105/*
106 * These are the 'tuning knobs' of the scheduler:
107 *
Dmitry Adamushkoa4ec24b2007-10-15 17:00:13 +0200108 * default timeslice is 100 msecs (used only for SCHED_RR tasks).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 * Timeslices get refilled after they expire.
110 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111#define DEF_TIMESLICE (100 * HZ / 1000)
Peter Williams2dd73a42006-06-27 02:54:34 -0700112
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +0200113/*
114 * single value that denotes runtime == period, ie unlimited time.
115 */
116#define RUNTIME_INF ((u64)~0ULL)
117
Eric Dumazet5517d862007-05-08 00:32:57 -0700118#ifdef CONFIG_SMP
119/*
120 * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
121 * Since cpu_power is a 'constant', we can use a reciprocal divide.
122 */
123static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load)
124{
125 return reciprocal_divide(load, sg->reciprocal_cpu_power);
126}
127
128/*
129 * Each time a sched group cpu_power is changed,
130 * we must compute its reciprocal value
131 */
132static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val)
133{
134 sg->__cpu_power += val;
135 sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power);
136}
137#endif
138
Ingo Molnare05606d2007-07-09 18:51:59 +0200139static inline int rt_policy(int policy)
140{
Roel Kluin3f33a7c2008-05-13 23:44:11 +0200141 if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR))
Ingo Molnare05606d2007-07-09 18:51:59 +0200142 return 1;
143 return 0;
144}
145
146static inline int task_has_rt_policy(struct task_struct *p)
147{
148 return rt_policy(p->policy);
149}
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151/*
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200152 * This is the priority-queue data structure of the RT scheduling class:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 */
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200154struct rt_prio_array {
155 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
Dmitry Adamushko20b63312008-06-11 00:58:30 +0200156 struct list_head queue[MAX_RT_PRIO];
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200157};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +0200159struct rt_bandwidth {
Ingo Molnarea736ed2008-03-25 13:51:45 +0100160 /* nests inside the rq lock: */
161 spinlock_t rt_runtime_lock;
162 ktime_t rt_period;
163 u64 rt_runtime;
164 struct hrtimer rt_period_timer;
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +0200165};
166
167static struct rt_bandwidth def_rt_bandwidth;
168
169static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
170
171static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)
172{
173 struct rt_bandwidth *rt_b =
174 container_of(timer, struct rt_bandwidth, rt_period_timer);
175 ktime_t now;
176 int overrun;
177 int idle = 0;
178
179 for (;;) {
180 now = hrtimer_cb_get_time(timer);
181 overrun = hrtimer_forward(timer, now, rt_b->rt_period);
182
183 if (!overrun)
184 break;
185
186 idle = do_sched_rt_period_timer(rt_b, overrun);
187 }
188
189 return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
190}
191
192static
193void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
194{
195 rt_b->rt_period = ns_to_ktime(period);
196 rt_b->rt_runtime = runtime;
197
Peter Zijlstraac086bc2008-04-19 19:44:58 +0200198 spin_lock_init(&rt_b->rt_runtime_lock);
199
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +0200200 hrtimer_init(&rt_b->rt_period_timer,
201 CLOCK_MONOTONIC, HRTIMER_MODE_REL);
202 rt_b->rt_period_timer.function = sched_rt_period_timer;
203 rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
204}
205
206static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
207{
208 ktime_t now;
209
210 if (rt_b->rt_runtime == RUNTIME_INF)
211 return;
212
213 if (hrtimer_active(&rt_b->rt_period_timer))
214 return;
215
216 spin_lock(&rt_b->rt_runtime_lock);
217 for (;;) {
218 if (hrtimer_active(&rt_b->rt_period_timer))
219 break;
220
221 now = hrtimer_cb_get_time(&rt_b->rt_period_timer);
222 hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period);
223 hrtimer_start(&rt_b->rt_period_timer,
224 rt_b->rt_period_timer.expires,
225 HRTIMER_MODE_ABS);
226 }
227 spin_unlock(&rt_b->rt_runtime_lock);
228}
229
230#ifdef CONFIG_RT_GROUP_SCHED
231static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
232{
233 hrtimer_cancel(&rt_b->rt_period_timer);
234}
235#endif
236
Heiko Carstens712555e2008-04-28 11:33:07 +0200237/*
238 * sched_domains_mutex serializes calls to arch_init_sched_domains,
239 * detach_destroy_domains and partition_sched_domains.
240 */
241static DEFINE_MUTEX(sched_domains_mutex);
242
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100243#ifdef CONFIG_GROUP_SCHED
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200244
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700245#include <linux/cgroup.h>
246
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200247struct cfs_rq;
248
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100249static LIST_HEAD(task_groups);
250
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200251/* task group related information */
Ingo Molnar4cf86d72007-10-15 17:00:14 +0200252struct task_group {
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100253#ifdef CONFIG_CGROUP_SCHED
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700254 struct cgroup_subsys_state css;
255#endif
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100256
257#ifdef CONFIG_FAIR_GROUP_SCHED
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200258 /* schedulable entities of this group on each cpu */
259 struct sched_entity **se;
260 /* runqueue "owned" by this group on each cpu */
261 struct cfs_rq **cfs_rq;
262 unsigned long shares;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100263#endif
264
265#ifdef CONFIG_RT_GROUP_SCHED
266 struct sched_rt_entity **rt_se;
267 struct rt_rq **rt_rq;
268
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +0200269 struct rt_bandwidth rt_bandwidth;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100270#endif
Srivatsa Vaddagiri6b2d7702008-01-25 21:08:00 +0100271
Srivatsa Vaddagiriae8393e2007-10-29 21:18:11 +0100272 struct rcu_head rcu;
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100273 struct list_head list;
Peter Zijlstraf473aa52008-04-19 19:45:00 +0200274
275 struct task_group *parent;
276 struct list_head siblings;
277 struct list_head children;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200278};
279
Dhaval Giani354d60c2008-04-19 19:44:59 +0200280#ifdef CONFIG_USER_SCHED
Peter Zijlstraeff766a2008-04-19 19:45:00 +0200281
282/*
283 * Root task group.
284 * Every UID task group (including init_task_group aka UID-0) will
285 * be a child to this group.
286 */
287struct task_group root_task_group;
288
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100289#ifdef CONFIG_FAIR_GROUP_SCHED
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200290/* Default task group's sched entity on each cpu */
291static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
292/* Default task group's cfs_rq on each cpu */
293static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +0200294#endif /* CONFIG_FAIR_GROUP_SCHED */
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100295
296#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100297static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
298static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +0200299#endif /* CONFIG_RT_GROUP_SCHED */
300#else /* !CONFIG_FAIR_GROUP_SCHED */
Peter Zijlstraeff766a2008-04-19 19:45:00 +0200301#define root_task_group init_task_group
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +0200302#endif /* CONFIG_FAIR_GROUP_SCHED */
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100303
Peter Zijlstra8ed36992008-02-13 15:45:39 +0100304/* task_group_lock serializes add/remove of task groups and also changes to
Srivatsa Vaddagiriec2c5072008-01-25 21:07:59 +0100305 * a task group's cpu shares.
306 */
Peter Zijlstra8ed36992008-02-13 15:45:39 +0100307static DEFINE_SPINLOCK(task_group_lock);
Srivatsa Vaddagiriec2c5072008-01-25 21:07:59 +0100308
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100309#ifdef CONFIG_FAIR_GROUP_SCHED
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100310#ifdef CONFIG_USER_SCHED
Ingo Molnar0eab9142008-01-25 21:08:19 +0100311# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +0200312#else /* !CONFIG_USER_SCHED */
Srivatsa Vaddagiri93f992c2008-01-25 21:07:59 +0100313# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +0200314#endif /* CONFIG_USER_SCHED */
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200315
Miao Xiecb4ad1f2008-04-28 12:54:56 +0800316/*
Lai Jiangshan2e084782008-06-12 16:42:58 +0800317 * A weight of 0 or 1 can cause arithmetics problems.
318 * A weight of a cfs_rq is the sum of weights of which entities
319 * are queued on this cfs_rq, so a weight of a entity should not be
320 * too large, so as the shares value of a task group.
Miao Xiecb4ad1f2008-04-28 12:54:56 +0800321 * (The default weight is 1024 - so there's no practical
322 * limitation from this.)
323 */
Peter Zijlstra18d95a22008-04-19 19:45:00 +0200324#define MIN_SHARES 2
Lai Jiangshan2e084782008-06-12 16:42:58 +0800325#define MAX_SHARES (1UL << 18)
Peter Zijlstra18d95a22008-04-19 19:45:00 +0200326
Srivatsa Vaddagiri93f992c2008-01-25 21:07:59 +0100327static int init_task_group_load = INIT_TASK_GROUP_LOAD;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100328#endif
329
330/* Default task group.
331 * Every task in system belong to this group at bootup.
332 */
Mike Travis434d53b2008-04-04 18:11:04 -0700333struct task_group init_task_group;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200334
335/* return group to which a task belongs */
Ingo Molnar4cf86d72007-10-15 17:00:14 +0200336static inline struct task_group *task_group(struct task_struct *p)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200337{
Ingo Molnar4cf86d72007-10-15 17:00:14 +0200338 struct task_group *tg;
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +0200339
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100340#ifdef CONFIG_USER_SCHED
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200341 tg = p->user->tg;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100342#elif defined(CONFIG_CGROUP_SCHED)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -0700343 tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
344 struct task_group, css);
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200345#else
Ingo Molnar41a2d6c2007-12-05 15:46:09 +0100346 tg = &init_task_group;
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200347#endif
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +0200348 return tg;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200349}
350
351/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100352static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200353{
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100354#ifdef CONFIG_FAIR_GROUP_SCHED
Dmitry Adamushkoce96b5a2007-11-15 20:57:40 +0100355 p->se.cfs_rq = task_group(p)->cfs_rq[cpu];
356 p->se.parent = task_group(p)->se[cpu];
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100357#endif
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100358
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100359#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100360 p->rt.rt_rq = task_group(p)->rt_rq[cpu];
361 p->rt.parent = task_group(p)->rt_se[cpu];
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100362#endif
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200363}
364
365#else
366
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100367static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
Peter Zijlstra83378262008-06-27 13:41:37 +0200368static inline struct task_group *task_group(struct task_struct *p)
369{
370 return NULL;
371}
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200372
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100373#endif /* CONFIG_GROUP_SCHED */
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +0200374
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200375/* CFS-related fields in a runqueue */
376struct cfs_rq {
377 struct load_weight load;
378 unsigned long nr_running;
379
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200380 u64 exec_clock;
Ingo Molnare9acbff2007-10-15 17:00:04 +0200381 u64 min_vruntime;
Peter Zijlstra103638d92008-06-27 13:41:16 +0200382 u64 pair_start;
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200383
384 struct rb_root tasks_timeline;
385 struct rb_node *rb_leftmost;
Peter Zijlstra4a55bd52008-04-19 19:45:00 +0200386
387 struct list_head tasks;
388 struct list_head *balance_iterator;
389
390 /*
391 * 'curr' points to currently running entity on this cfs_rq.
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200392 * It is set to NULL otherwise (i.e when none are currently running).
393 */
Peter Zijlstraaa2ac252008-03-14 21:12:12 +0100394 struct sched_entity *curr, *next;
Peter Zijlstraddc97292007-10-15 17:00:10 +0200395
396 unsigned long nr_spread_over;
397
Ingo Molnar62160e32007-10-15 17:00:03 +0200398#ifdef CONFIG_FAIR_GROUP_SCHED
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200399 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
400
Ingo Molnar41a2d6c2007-12-05 15:46:09 +0100401 /*
402 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200403 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
404 * (like users, containers etc.)
405 *
406 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
407 * list is used during load balance.
408 */
Ingo Molnar41a2d6c2007-12-05 15:46:09 +0100409 struct list_head leaf_cfs_rq_list;
410 struct task_group *tg; /* group that "owns" this runqueue */
Peter Zijlstrac09595f2008-06-27 13:41:14 +0200411
412#ifdef CONFIG_SMP
Peter Zijlstrac09595f2008-06-27 13:41:14 +0200413 /*
Peter Zijlstrac8cba852008-06-27 13:41:23 +0200414 * the part of load.weight contributed by tasks
Peter Zijlstrac09595f2008-06-27 13:41:14 +0200415 */
Peter Zijlstrac8cba852008-06-27 13:41:23 +0200416 unsigned long task_weight;
Peter Zijlstrac09595f2008-06-27 13:41:14 +0200417
Peter Zijlstrac8cba852008-06-27 13:41:23 +0200418 /*
419 * h_load = weight * f(tg)
420 *
421 * Where f(tg) is the recursive weight fraction assigned to
422 * this group.
423 */
424 unsigned long h_load;
Peter Zijlstrac09595f2008-06-27 13:41:14 +0200425
Peter Zijlstrac8cba852008-06-27 13:41:23 +0200426 /*
427 * this cpu's part of tg->shares
428 */
429 unsigned long shares;
Peter Zijlstraf1d239f2008-06-27 13:41:38 +0200430
431 /*
432 * load.weight at the time we set shares
433 */
434 unsigned long rq_weight;
Peter Zijlstrac09595f2008-06-27 13:41:14 +0200435#endif
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200436#endif
437};
438
439/* Real-Time classes' related field in a runqueue: */
440struct rt_rq {
441 struct rt_prio_array active;
Steven Rostedt63489e42008-01-25 21:08:03 +0100442 unsigned long rt_nr_running;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100443#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100444 int highest_prio; /* highest queued rt task prio */
445#endif
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100446#ifdef CONFIG_SMP
Gregory Haskins73fe6aa2008-01-25 21:08:07 +0100447 unsigned long rt_nr_migratory;
Gregory Haskinsa22d7fc2008-01-25 21:08:12 +0100448 int overloaded;
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100449#endif
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100450 int rt_throttled;
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100451 u64 rt_time;
Peter Zijlstraac086bc2008-04-19 19:44:58 +0200452 u64 rt_runtime;
Ingo Molnarea736ed2008-03-25 13:51:45 +0100453 /* Nests inside the rq lock: */
Peter Zijlstraac086bc2008-04-19 19:44:58 +0200454 spinlock_t rt_runtime_lock;
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100455
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100456#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra23b0fdf2008-02-13 15:45:39 +0100457 unsigned long rt_nr_boosted;
458
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100459 struct rq *rq;
460 struct list_head leaf_rt_rq_list;
461 struct task_group *tg;
462 struct sched_rt_entity *rt_se;
463#endif
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200464};
465
Gregory Haskins57d885f2008-01-25 21:08:18 +0100466#ifdef CONFIG_SMP
467
468/*
469 * We add the notion of a root-domain which will be used to define per-domain
Ingo Molnar0eab9142008-01-25 21:08:19 +0100470 * variables. Each exclusive cpuset essentially defines an island domain by
471 * fully partitioning the member cpus from any other cpuset. Whenever a new
Gregory Haskins57d885f2008-01-25 21:08:18 +0100472 * exclusive cpuset is created, we also create and attach a new root-domain
473 * object.
474 *
Gregory Haskins57d885f2008-01-25 21:08:18 +0100475 */
476struct root_domain {
477 atomic_t refcount;
478 cpumask_t span;
479 cpumask_t online;
Gregory Haskins637f5082008-01-25 21:08:18 +0100480
Ingo Molnar0eab9142008-01-25 21:08:19 +0100481 /*
Gregory Haskins637f5082008-01-25 21:08:18 +0100482 * The "RT overload" flag: it gets set if a CPU has more than
483 * one runnable RT task.
484 */
485 cpumask_t rto_mask;
Ingo Molnar0eab9142008-01-25 21:08:19 +0100486 atomic_t rto_count;
Gregory Haskins6e0534f2008-05-12 21:21:01 +0200487#ifdef CONFIG_SMP
488 struct cpupri cpupri;
489#endif
Gregory Haskins57d885f2008-01-25 21:08:18 +0100490};
491
Gregory Haskinsdc938522008-01-25 21:08:26 +0100492/*
493 * By default the system creates a single root-domain with all cpus as
494 * members (mimicking the global state we have today).
495 */
Gregory Haskins57d885f2008-01-25 21:08:18 +0100496static struct root_domain def_root_domain;
497
498#endif
499
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200500/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 * This is the main, per-CPU runqueue data structure.
502 *
503 * Locking rule: those places that want to lock multiple runqueues
504 * (such as the load balancing or the thread migration code), lock
505 * acquire operations must be ordered by ascending &runqueue.
506 */
Ingo Molnar70b97a72006-07-03 00:25:42 -0700507struct rq {
Ingo Molnard8016492007-10-18 21:32:55 +0200508 /* runqueue lock: */
509 spinlock_t lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
511 /*
512 * nr_running and cpu_load should be in the same cacheline because
513 * remote CPUs use both these fields when doing load calculation.
514 */
515 unsigned long nr_running;
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200516 #define CPU_LOAD_IDX_MAX 5
517 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
Siddha, Suresh Bbdecea32007-05-08 00:32:48 -0700518 unsigned char idle_at_tick;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -0700519#ifdef CONFIG_NO_HZ
Guillaume Chazarain15934a32008-04-19 19:44:57 +0200520 unsigned long last_tick_seen;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -0700521 unsigned char in_nohz_recently;
522#endif
Ingo Molnard8016492007-10-18 21:32:55 +0200523 /* capture load from *all* tasks on this cpu: */
524 struct load_weight load;
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200525 unsigned long nr_load_updates;
526 u64 nr_switches;
527
528 struct cfs_rq cfs;
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100529 struct rt_rq rt;
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100530
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200531#ifdef CONFIG_FAIR_GROUP_SCHED
Ingo Molnard8016492007-10-18 21:32:55 +0200532 /* list of leaf cfs_rq on this cpu: */
533 struct list_head leaf_cfs_rq_list;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100534#endif
535#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +0100536 struct list_head leaf_rt_rq_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538
539 /*
540 * This is part of a global counter where only the total sum
541 * over all CPUs matters. A task can increase this counter on
542 * one CPU and if it got migrated afterwards it may decrease
543 * it on another CPU. Always updated under the runqueue lock:
544 */
545 unsigned long nr_uninterruptible;
546
Ingo Molnar36c8b582006-07-03 00:25:41 -0700547 struct task_struct *curr, *idle;
Christoph Lameterc9819f42006-12-10 02:20:25 -0800548 unsigned long next_balance;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 struct mm_struct *prev_mm;
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200550
Peter Zijlstra3e51f332008-05-03 18:29:28 +0200551 u64 clock;
Ingo Molnar6aa645e2007-07-09 18:51:58 +0200552
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 atomic_t nr_iowait;
554
555#ifdef CONFIG_SMP
Ingo Molnar0eab9142008-01-25 21:08:19 +0100556 struct root_domain *rd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 struct sched_domain *sd;
558
559 /* For active balancing */
560 int active_balance;
561 int push_cpu;
Ingo Molnard8016492007-10-18 21:32:55 +0200562 /* cpu of this runqueue: */
563 int cpu;
Gregory Haskins1f11eb62008-06-04 15:04:05 -0400564 int online;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
Peter Zijlstraa8a51d52008-06-27 13:41:26 +0200566 unsigned long avg_load_per_task;
567
Ingo Molnar36c8b582006-07-03 00:25:41 -0700568 struct task_struct *migration_thread;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 struct list_head migration_queue;
570#endif
571
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +0100572#ifdef CONFIG_SCHED_HRTICK
573 unsigned long hrtick_flags;
574 ktime_t hrtick_expire;
575 struct hrtimer hrtick_timer;
576#endif
577
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578#ifdef CONFIG_SCHEDSTATS
579 /* latency stats */
580 struct sched_info rq_sched_info;
581
582 /* sys_sched_yield() stats */
Ken Chen480b9432007-10-18 21:32:56 +0200583 unsigned int yld_exp_empty;
584 unsigned int yld_act_empty;
585 unsigned int yld_both_empty;
586 unsigned int yld_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588 /* schedule() stats */
Ken Chen480b9432007-10-18 21:32:56 +0200589 unsigned int sched_switch;
590 unsigned int sched_count;
591 unsigned int sched_goidle;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
593 /* try_to_wake_up() stats */
Ken Chen480b9432007-10-18 21:32:56 +0200594 unsigned int ttwu_count;
595 unsigned int ttwu_local;
Ingo Molnarb8efb562007-10-15 17:00:10 +0200596
597 /* BKL stats */
Ken Chen480b9432007-10-18 21:32:56 +0200598 unsigned int bkl_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599#endif
Ingo Molnarfcb99372006-07-03 00:25:10 -0700600 struct lock_class_key rq_lock_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601};
602
Fenghua Yuf34e3b62007-07-19 01:48:13 -0700603static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
Ingo Molnardd41f592007-07-09 18:51:59 +0200605static inline void check_preempt_curr(struct rq *rq, struct task_struct *p)
606{
607 rq->curr->sched_class->check_preempt_curr(rq, p);
608}
609
Christoph Lameter0a2966b2006-09-25 23:30:51 -0700610static inline int cpu_of(struct rq *rq)
611{
612#ifdef CONFIG_SMP
613 return rq->cpu;
614#else
615 return 0;
616#endif
617}
618
Ingo Molnar20d315d2007-07-09 18:51:58 +0200619/*
Nick Piggin674311d2005-06-25 14:57:27 -0700620 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -0700621 * See detach_destroy_domains: synchronize_sched for details.
Nick Piggin674311d2005-06-25 14:57:27 -0700622 *
623 * The domain tree of any CPU may only be accessed from within
624 * preempt-disabled sections.
625 */
Ingo Molnar48f24c42006-07-03 00:25:40 -0700626#define for_each_domain(cpu, __sd) \
627 for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
630#define this_rq() (&__get_cpu_var(runqueues))
631#define task_rq(p) cpu_rq(task_cpu(p))
632#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
633
Peter Zijlstra3e51f332008-05-03 18:29:28 +0200634static inline void update_rq_clock(struct rq *rq)
635{
636 rq->clock = sched_clock_cpu(cpu_of(rq));
637}
638
Ingo Molnare436d802007-07-19 21:28:35 +0200639/*
Ingo Molnarbf5c91b2007-10-15 17:00:04 +0200640 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
641 */
642#ifdef CONFIG_SCHED_DEBUG
643# define const_debug __read_mostly
644#else
645# define const_debug static const
646#endif
647
648/*
649 * Debugging: various feature bits
650 */
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200651
652#define SCHED_FEAT(name, enabled) \
653 __SCHED_FEAT_##name ,
654
Ingo Molnarbf5c91b2007-10-15 17:00:04 +0200655enum {
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200656#include "sched_features.h"
Ingo Molnarbf5c91b2007-10-15 17:00:04 +0200657};
658
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200659#undef SCHED_FEAT
Ingo Molnarbf5c91b2007-10-15 17:00:04 +0200660
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200661#define SCHED_FEAT(name, enabled) \
662 (1UL << __SCHED_FEAT_##name) * enabled |
663
664const_debug unsigned int sysctl_sched_features =
665#include "sched_features.h"
666 0;
667
668#undef SCHED_FEAT
669
670#ifdef CONFIG_SCHED_DEBUG
671#define SCHED_FEAT(name, enabled) \
672 #name ,
673
Harvey Harrison983ed7a2008-04-24 18:17:55 -0700674static __read_mostly char *sched_feat_names[] = {
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200675#include "sched_features.h"
676 NULL
677};
678
679#undef SCHED_FEAT
680
Harvey Harrison983ed7a2008-04-24 18:17:55 -0700681static int sched_feat_open(struct inode *inode, struct file *filp)
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200682{
683 filp->private_data = inode->i_private;
684 return 0;
685}
686
687static ssize_t
688sched_feat_read(struct file *filp, char __user *ubuf,
689 size_t cnt, loff_t *ppos)
690{
691 char *buf;
692 int r = 0;
693 int len = 0;
694 int i;
695
696 for (i = 0; sched_feat_names[i]; i++) {
697 len += strlen(sched_feat_names[i]);
698 len += 4;
699 }
700
701 buf = kmalloc(len + 2, GFP_KERNEL);
702 if (!buf)
703 return -ENOMEM;
704
705 for (i = 0; sched_feat_names[i]; i++) {
706 if (sysctl_sched_features & (1UL << i))
707 r += sprintf(buf + r, "%s ", sched_feat_names[i]);
708 else
Ingo Molnarc24b7c52008-04-18 10:55:34 +0200709 r += sprintf(buf + r, "NO_%s ", sched_feat_names[i]);
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200710 }
711
712 r += sprintf(buf + r, "\n");
713 WARN_ON(r >= len + 2);
714
715 r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
716
717 kfree(buf);
718
719 return r;
720}
721
722static ssize_t
723sched_feat_write(struct file *filp, const char __user *ubuf,
724 size_t cnt, loff_t *ppos)
725{
726 char buf[64];
727 char *cmp = buf;
728 int neg = 0;
729 int i;
730
731 if (cnt > 63)
732 cnt = 63;
733
734 if (copy_from_user(&buf, ubuf, cnt))
735 return -EFAULT;
736
737 buf[cnt] = 0;
738
Ingo Molnarc24b7c52008-04-18 10:55:34 +0200739 if (strncmp(buf, "NO_", 3) == 0) {
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200740 neg = 1;
741 cmp += 3;
742 }
743
744 for (i = 0; sched_feat_names[i]; i++) {
745 int len = strlen(sched_feat_names[i]);
746
747 if (strncmp(cmp, sched_feat_names[i], len) == 0) {
748 if (neg)
749 sysctl_sched_features &= ~(1UL << i);
750 else
751 sysctl_sched_features |= (1UL << i);
752 break;
753 }
754 }
755
756 if (!sched_feat_names[i])
757 return -EINVAL;
758
759 filp->f_pos += cnt;
760
761 return cnt;
762}
763
764static struct file_operations sched_feat_fops = {
765 .open = sched_feat_open,
766 .read = sched_feat_read,
767 .write = sched_feat_write,
768};
769
770static __init int sched_init_debug(void)
771{
Peter Zijlstraf00b45c2008-04-19 19:45:00 +0200772 debugfs_create_file("sched_features", 0644, NULL, NULL,
773 &sched_feat_fops);
774
775 return 0;
776}
777late_initcall(sched_init_debug);
778
779#endif
780
781#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
Ingo Molnarbf5c91b2007-10-15 17:00:04 +0200782
783/*
Peter Zijlstrab82d9fd2007-11-09 22:39:39 +0100784 * Number of tasks to iterate in a single balance run.
785 * Limited because this is done with IRQs disabled.
786 */
787const_debug unsigned int sysctl_sched_nr_migrate = 32;
788
789/*
Peter Zijlstra2398f2c2008-06-27 13:41:35 +0200790 * ratelimit for updating the group shares.
791 * default: 0.5ms
792 */
793const_debug unsigned int sysctl_sched_shares_ratelimit = 500000;
794
795/*
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +0100796 * period over which we measure -rt task cpu usage in us.
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100797 * default: 1s
798 */
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +0100799unsigned int sysctl_sched_rt_period = 1000000;
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100800
Ingo Molnar6892b752008-02-13 14:02:36 +0100801static __read_mostly int scheduler_running;
802
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100803/*
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +0100804 * part of the period that we allow rt tasks to run in us.
805 * default: 0.95s
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100806 */
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +0100807int sysctl_sched_rt_runtime = 950000;
808
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +0200809static inline u64 global_rt_period(void)
810{
811 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
812}
813
814static inline u64 global_rt_runtime(void)
815{
816 if (sysctl_sched_rt_period < 0)
817 return RUNTIME_INF;
818
819 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
820}
Peter Zijlstrafa85ae22008-01-25 21:08:29 +0100821
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822#ifndef prepare_arch_switch
Nick Piggin4866cde2005-06-25 14:57:23 -0700823# define prepare_arch_switch(next) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824#endif
Nick Piggin4866cde2005-06-25 14:57:23 -0700825#ifndef finish_arch_switch
826# define finish_arch_switch(prev) do { } while (0)
827#endif
828
Dmitry Adamushko051a1d12007-12-18 15:21:13 +0100829static inline int task_current(struct rq *rq, struct task_struct *p)
830{
831 return rq->curr == p;
832}
833
Nick Piggin4866cde2005-06-25 14:57:23 -0700834#ifndef __ARCH_WANT_UNLOCKED_CTXSW
Ingo Molnar70b97a72006-07-03 00:25:42 -0700835static inline int task_running(struct rq *rq, struct task_struct *p)
Nick Piggin4866cde2005-06-25 14:57:23 -0700836{
Dmitry Adamushko051a1d12007-12-18 15:21:13 +0100837 return task_current(rq, p);
Nick Piggin4866cde2005-06-25 14:57:23 -0700838}
839
Ingo Molnar70b97a72006-07-03 00:25:42 -0700840static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
Nick Piggin4866cde2005-06-25 14:57:23 -0700841{
842}
843
Ingo Molnar70b97a72006-07-03 00:25:42 -0700844static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
Nick Piggin4866cde2005-06-25 14:57:23 -0700845{
Ingo Molnarda04c032005-09-13 11:17:59 +0200846#ifdef CONFIG_DEBUG_SPINLOCK
847 /* this is a valid case when another task releases the spinlock */
848 rq->lock.owner = current;
849#endif
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700850 /*
851 * If we are tracking spinlock dependencies then we have to
852 * fix up the runqueue lock - which gets 'carried over' from
853 * prev into current:
854 */
855 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
856
Nick Piggin4866cde2005-06-25 14:57:23 -0700857 spin_unlock_irq(&rq->lock);
858}
859
860#else /* __ARCH_WANT_UNLOCKED_CTXSW */
Ingo Molnar70b97a72006-07-03 00:25:42 -0700861static inline int task_running(struct rq *rq, struct task_struct *p)
Nick Piggin4866cde2005-06-25 14:57:23 -0700862{
863#ifdef CONFIG_SMP
864 return p->oncpu;
865#else
Dmitry Adamushko051a1d12007-12-18 15:21:13 +0100866 return task_current(rq, p);
Nick Piggin4866cde2005-06-25 14:57:23 -0700867#endif
868}
869
Ingo Molnar70b97a72006-07-03 00:25:42 -0700870static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
Nick Piggin4866cde2005-06-25 14:57:23 -0700871{
872#ifdef CONFIG_SMP
873 /*
874 * We can optimise this out completely for !SMP, because the
875 * SMP rebalancing from interrupt is the only thing that cares
876 * here.
877 */
878 next->oncpu = 1;
879#endif
880#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
881 spin_unlock_irq(&rq->lock);
882#else
883 spin_unlock(&rq->lock);
884#endif
885}
886
Ingo Molnar70b97a72006-07-03 00:25:42 -0700887static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
Nick Piggin4866cde2005-06-25 14:57:23 -0700888{
889#ifdef CONFIG_SMP
890 /*
891 * After ->oncpu is cleared, the task can be moved to a different CPU.
892 * We must ensure this doesn't happen until the switch is completely
893 * finished.
894 */
895 smp_wmb();
896 prev->oncpu = 0;
897#endif
898#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
899 local_irq_enable();
900#endif
901}
902#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
904/*
Ingo Molnarb29739f2006-06-27 02:54:51 -0700905 * __task_rq_lock - lock the runqueue a given task resides on.
906 * Must be called interrupts disabled.
907 */
Ingo Molnar70b97a72006-07-03 00:25:42 -0700908static inline struct rq *__task_rq_lock(struct task_struct *p)
Ingo Molnarb29739f2006-06-27 02:54:51 -0700909 __acquires(rq->lock)
910{
Andi Kleen3a5c3592007-10-15 17:00:14 +0200911 for (;;) {
912 struct rq *rq = task_rq(p);
913 spin_lock(&rq->lock);
914 if (likely(rq == task_rq(p)))
915 return rq;
Ingo Molnarb29739f2006-06-27 02:54:51 -0700916 spin_unlock(&rq->lock);
Ingo Molnarb29739f2006-06-27 02:54:51 -0700917 }
Ingo Molnarb29739f2006-06-27 02:54:51 -0700918}
919
920/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 * task_rq_lock - lock the runqueue a given task resides on and disable
Ingo Molnar41a2d6c2007-12-05 15:46:09 +0100922 * interrupts. Note the ordering: we can safely lookup the task_rq without
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 * explicitly disabling preemption.
924 */
Ingo Molnar70b97a72006-07-03 00:25:42 -0700925static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 __acquires(rq->lock)
927{
Ingo Molnar70b97a72006-07-03 00:25:42 -0700928 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929
Andi Kleen3a5c3592007-10-15 17:00:14 +0200930 for (;;) {
931 local_irq_save(*flags);
932 rq = task_rq(p);
933 spin_lock(&rq->lock);
934 if (likely(rq == task_rq(p)))
935 return rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 spin_unlock_irqrestore(&rq->lock, *flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938}
939
Alexey Dobriyana9957442007-10-15 17:00:13 +0200940static void __task_rq_unlock(struct rq *rq)
Ingo Molnarb29739f2006-06-27 02:54:51 -0700941 __releases(rq->lock)
942{
943 spin_unlock(&rq->lock);
944}
945
Ingo Molnar70b97a72006-07-03 00:25:42 -0700946static inline void task_rq_unlock(struct rq *rq, unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 __releases(rq->lock)
948{
949 spin_unlock_irqrestore(&rq->lock, *flags);
950}
951
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952/*
Robert P. J. Daycc2a73b2006-12-10 02:20:00 -0800953 * this_rq_lock - lock this runqueue and disable interrupts.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 */
Alexey Dobriyana9957442007-10-15 17:00:13 +0200955static struct rq *this_rq_lock(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 __acquires(rq->lock)
957{
Ingo Molnar70b97a72006-07-03 00:25:42 -0700958 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959
960 local_irq_disable();
961 rq = this_rq();
962 spin_lock(&rq->lock);
963
964 return rq;
965}
966
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +0100967static void __resched_task(struct task_struct *p, int tif_bit);
968
969static inline void resched_task(struct task_struct *p)
970{
971 __resched_task(p, TIF_NEED_RESCHED);
972}
973
974#ifdef CONFIG_SCHED_HRTICK
975/*
976 * Use HR-timers to deliver accurate preemption points.
977 *
978 * Its all a bit involved since we cannot program an hrt while holding the
979 * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
980 * reschedule event.
981 *
982 * When we get rescheduled we reprogram the hrtick_timer outside of the
983 * rq->lock.
984 */
985static inline void resched_hrt(struct task_struct *p)
986{
987 __resched_task(p, TIF_HRTICK_RESCHED);
988}
989
990static inline void resched_rq(struct rq *rq)
991{
992 unsigned long flags;
993
994 spin_lock_irqsave(&rq->lock, flags);
995 resched_task(rq->curr);
996 spin_unlock_irqrestore(&rq->lock, flags);
997}
998
999enum {
1000 HRTICK_SET, /* re-programm hrtick_timer */
1001 HRTICK_RESET, /* not a new slice */
Peter Zijlstrab328ca12008-04-29 10:02:46 +02001002 HRTICK_BLOCK, /* stop hrtick operations */
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001003};
1004
1005/*
1006 * Use hrtick when:
1007 * - enabled by features
1008 * - hrtimer is actually high res
1009 */
1010static inline int hrtick_enabled(struct rq *rq)
1011{
1012 if (!sched_feat(HRTICK))
1013 return 0;
Peter Zijlstrab328ca12008-04-29 10:02:46 +02001014 if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags)))
1015 return 0;
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001016 return hrtimer_is_hres_active(&rq->hrtick_timer);
1017}
1018
1019/*
1020 * Called to set the hrtick timer state.
1021 *
1022 * called with rq->lock held and irqs disabled
1023 */
1024static void hrtick_start(struct rq *rq, u64 delay, int reset)
1025{
1026 assert_spin_locked(&rq->lock);
1027
1028 /*
1029 * preempt at: now + delay
1030 */
1031 rq->hrtick_expire =
1032 ktime_add_ns(rq->hrtick_timer.base->get_time(), delay);
1033 /*
1034 * indicate we need to program the timer
1035 */
1036 __set_bit(HRTICK_SET, &rq->hrtick_flags);
1037 if (reset)
1038 __set_bit(HRTICK_RESET, &rq->hrtick_flags);
1039
1040 /*
1041 * New slices are called from the schedule path and don't need a
1042 * forced reschedule.
1043 */
1044 if (reset)
1045 resched_hrt(rq->curr);
1046}
1047
1048static void hrtick_clear(struct rq *rq)
1049{
1050 if (hrtimer_active(&rq->hrtick_timer))
1051 hrtimer_cancel(&rq->hrtick_timer);
1052}
1053
1054/*
1055 * Update the timer from the possible pending state.
1056 */
1057static void hrtick_set(struct rq *rq)
1058{
1059 ktime_t time;
1060 int set, reset;
1061 unsigned long flags;
1062
1063 WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
1064
1065 spin_lock_irqsave(&rq->lock, flags);
1066 set = __test_and_clear_bit(HRTICK_SET, &rq->hrtick_flags);
1067 reset = __test_and_clear_bit(HRTICK_RESET, &rq->hrtick_flags);
1068 time = rq->hrtick_expire;
1069 clear_thread_flag(TIF_HRTICK_RESCHED);
1070 spin_unlock_irqrestore(&rq->lock, flags);
1071
1072 if (set) {
1073 hrtimer_start(&rq->hrtick_timer, time, HRTIMER_MODE_ABS);
1074 if (reset && !hrtimer_active(&rq->hrtick_timer))
1075 resched_rq(rq);
1076 } else
1077 hrtick_clear(rq);
1078}
1079
1080/*
1081 * High-resolution timer tick.
1082 * Runs from hardirq context with interrupts disabled.
1083 */
1084static enum hrtimer_restart hrtick(struct hrtimer *timer)
1085{
1086 struct rq *rq = container_of(timer, struct rq, hrtick_timer);
1087
1088 WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
1089
1090 spin_lock(&rq->lock);
Peter Zijlstra3e51f332008-05-03 18:29:28 +02001091 update_rq_clock(rq);
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001092 rq->curr->sched_class->task_tick(rq, rq->curr, 1);
1093 spin_unlock(&rq->lock);
1094
1095 return HRTIMER_NORESTART;
1096}
1097
Rabin Vincent81d41d72008-05-11 05:55:33 +05301098#ifdef CONFIG_SMP
Peter Zijlstrab328ca12008-04-29 10:02:46 +02001099static void hotplug_hrtick_disable(int cpu)
1100{
1101 struct rq *rq = cpu_rq(cpu);
1102 unsigned long flags;
1103
1104 spin_lock_irqsave(&rq->lock, flags);
1105 rq->hrtick_flags = 0;
1106 __set_bit(HRTICK_BLOCK, &rq->hrtick_flags);
1107 spin_unlock_irqrestore(&rq->lock, flags);
1108
1109 hrtick_clear(rq);
1110}
1111
1112static void hotplug_hrtick_enable(int cpu)
1113{
1114 struct rq *rq = cpu_rq(cpu);
1115 unsigned long flags;
1116
1117 spin_lock_irqsave(&rq->lock, flags);
1118 __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags);
1119 spin_unlock_irqrestore(&rq->lock, flags);
1120}
1121
1122static int
1123hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
1124{
1125 int cpu = (int)(long)hcpu;
1126
1127 switch (action) {
1128 case CPU_UP_CANCELED:
1129 case CPU_UP_CANCELED_FROZEN:
1130 case CPU_DOWN_PREPARE:
1131 case CPU_DOWN_PREPARE_FROZEN:
1132 case CPU_DEAD:
1133 case CPU_DEAD_FROZEN:
1134 hotplug_hrtick_disable(cpu);
1135 return NOTIFY_OK;
1136
1137 case CPU_UP_PREPARE:
1138 case CPU_UP_PREPARE_FROZEN:
1139 case CPU_DOWN_FAILED:
1140 case CPU_DOWN_FAILED_FROZEN:
1141 case CPU_ONLINE:
1142 case CPU_ONLINE_FROZEN:
1143 hotplug_hrtick_enable(cpu);
1144 return NOTIFY_OK;
1145 }
1146
1147 return NOTIFY_DONE;
1148}
1149
1150static void init_hrtick(void)
1151{
1152 hotcpu_notifier(hotplug_hrtick, 0);
1153}
Rabin Vincent81d41d72008-05-11 05:55:33 +05301154#endif /* CONFIG_SMP */
Peter Zijlstrab328ca12008-04-29 10:02:46 +02001155
1156static void init_rq_hrtick(struct rq *rq)
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001157{
1158 rq->hrtick_flags = 0;
1159 hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1160 rq->hrtick_timer.function = hrtick;
1161 rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
1162}
1163
1164void hrtick_resched(void)
1165{
1166 struct rq *rq;
1167 unsigned long flags;
1168
1169 if (!test_thread_flag(TIF_HRTICK_RESCHED))
1170 return;
1171
1172 local_irq_save(flags);
1173 rq = cpu_rq(smp_processor_id());
1174 hrtick_set(rq);
1175 local_irq_restore(flags);
1176}
1177#else
1178static inline void hrtick_clear(struct rq *rq)
1179{
1180}
1181
1182static inline void hrtick_set(struct rq *rq)
1183{
1184}
1185
1186static inline void init_rq_hrtick(struct rq *rq)
1187{
1188}
1189
1190void hrtick_resched(void)
1191{
1192}
Peter Zijlstrab328ca12008-04-29 10:02:46 +02001193
1194static inline void init_hrtick(void)
1195{
1196}
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001197#endif
1198
Ingo Molnar1b9f19c2007-07-09 18:51:59 +02001199/*
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001200 * resched_task - mark a task 'to be rescheduled now'.
1201 *
1202 * On UP this means the setting of the need_resched flag, on SMP it
1203 * might also involve a cross-CPU call to trigger the scheduler on
1204 * the target CPU.
1205 */
1206#ifdef CONFIG_SMP
1207
1208#ifndef tsk_is_polling
1209#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
1210#endif
1211
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001212static void __resched_task(struct task_struct *p, int tif_bit)
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001213{
1214 int cpu;
1215
1216 assert_spin_locked(&task_rq(p)->lock);
1217
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001218 if (unlikely(test_tsk_thread_flag(p, tif_bit)))
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001219 return;
1220
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001221 set_tsk_thread_flag(p, tif_bit);
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001222
1223 cpu = task_cpu(p);
1224 if (cpu == smp_processor_id())
1225 return;
1226
1227 /* NEED_RESCHED must be visible before we test polling */
1228 smp_mb();
1229 if (!tsk_is_polling(p))
1230 smp_send_reschedule(cpu);
1231}
1232
1233static void resched_cpu(int cpu)
1234{
1235 struct rq *rq = cpu_rq(cpu);
1236 unsigned long flags;
1237
1238 if (!spin_trylock_irqsave(&rq->lock, flags))
1239 return;
1240 resched_task(cpu_curr(cpu));
1241 spin_unlock_irqrestore(&rq->lock, flags);
1242}
Thomas Gleixner06d83082008-03-22 09:20:24 +01001243
1244#ifdef CONFIG_NO_HZ
1245/*
1246 * When add_timer_on() enqueues a timer into the timer wheel of an
1247 * idle CPU then this timer might expire before the next timer event
1248 * which is scheduled to wake up that CPU. In case of a completely
1249 * idle system the next event might even be infinite time into the
1250 * future. wake_up_idle_cpu() ensures that the CPU is woken up and
1251 * leaves the inner idle loop so the newly added timer is taken into
1252 * account when the CPU goes back to idle and evaluates the timer
1253 * wheel for the next timer event.
1254 */
1255void wake_up_idle_cpu(int cpu)
1256{
1257 struct rq *rq = cpu_rq(cpu);
1258
1259 if (cpu == smp_processor_id())
1260 return;
1261
1262 /*
1263 * This is safe, as this function is called with the timer
1264 * wheel base lock of (cpu) held. When the CPU is on the way
1265 * to idle and has not yet set rq->curr to idle then it will
1266 * be serialized on the timer wheel base lock and take the new
1267 * timer into account automatically.
1268 */
1269 if (rq->curr != rq->idle)
1270 return;
1271
1272 /*
1273 * We can set TIF_RESCHED on the idle task of the other CPU
1274 * lockless. The worst case is that the other CPU runs the
1275 * idle task through an additional NOOP schedule()
1276 */
1277 set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED);
1278
1279 /* NEED_RESCHED must be visible before we test polling */
1280 smp_mb();
1281 if (!tsk_is_polling(rq->idle))
1282 smp_send_reschedule(cpu);
1283}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02001284#endif /* CONFIG_NO_HZ */
Thomas Gleixner06d83082008-03-22 09:20:24 +01001285
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02001286#else /* !CONFIG_SMP */
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001287static void __resched_task(struct task_struct *p, int tif_bit)
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001288{
1289 assert_spin_locked(&task_rq(p)->lock);
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01001290 set_tsk_thread_flag(p, tif_bit);
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001291}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02001292#endif /* CONFIG_SMP */
Ingo Molnarc24d20d2007-07-09 18:51:59 +02001293
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001294#if BITS_PER_LONG == 32
1295# define WMULT_CONST (~0UL)
1296#else
1297# define WMULT_CONST (1UL << 32)
1298#endif
1299
1300#define WMULT_SHIFT 32
1301
Ingo Molnar194081e2007-08-09 11:16:51 +02001302/*
1303 * Shift right and round:
1304 */
Ingo Molnarcf2ab462007-09-05 14:32:49 +02001305#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
Ingo Molnar194081e2007-08-09 11:16:51 +02001306
Peter Zijlstraa7be37a2008-06-27 13:41:11 +02001307/*
1308 * delta *= weight / lw
1309 */
Ingo Molnarcb1c4fc2007-08-02 17:41:40 +02001310static unsigned long
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001311calc_delta_mine(unsigned long delta_exec, unsigned long weight,
1312 struct load_weight *lw)
1313{
1314 u64 tmp;
1315
Lai Jiangshan7a232e02008-06-12 16:43:07 +08001316 if (!lw->inv_weight) {
1317 if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST))
1318 lw->inv_weight = 1;
1319 else
1320 lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2)
1321 / (lw->weight+1);
1322 }
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001323
1324 tmp = (u64)delta_exec * weight;
1325 /*
1326 * Check whether we'd overflow the 64-bit multiplication:
1327 */
Ingo Molnar194081e2007-08-09 11:16:51 +02001328 if (unlikely(tmp > WMULT_CONST))
Ingo Molnarcf2ab462007-09-05 14:32:49 +02001329 tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
Ingo Molnar194081e2007-08-09 11:16:51 +02001330 WMULT_SHIFT/2);
1331 else
Ingo Molnarcf2ab462007-09-05 14:32:49 +02001332 tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT);
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001333
Ingo Molnarecf691d2007-08-02 17:41:40 +02001334 return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001335}
1336
Ingo Molnar10919852007-10-15 17:00:04 +02001337static inline void update_load_add(struct load_weight *lw, unsigned long inc)
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001338{
1339 lw->weight += inc;
Ingo Molnare89996a2008-03-14 23:48:28 +01001340 lw->inv_weight = 0;
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001341}
1342
Ingo Molnar10919852007-10-15 17:00:04 +02001343static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001344{
1345 lw->weight -= dec;
Ingo Molnare89996a2008-03-14 23:48:28 +01001346 lw->inv_weight = 0;
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001347}
1348
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349/*
Peter Williams2dd73a42006-06-27 02:54:34 -07001350 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1351 * of tasks with abnormal "nice" values across CPUs the contribution that
1352 * each task makes to its run queue's load is weighted according to its
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01001353 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
Peter Williams2dd73a42006-06-27 02:54:34 -07001354 * scaled version of the new time slice allocation that they receive on time
1355 * slice expiry etc.
1356 */
1357
Ingo Molnardd41f592007-07-09 18:51:59 +02001358#define WEIGHT_IDLEPRIO 2
1359#define WMULT_IDLEPRIO (1 << 31)
1360
1361/*
1362 * Nice levels are multiplicative, with a gentle 10% change for every
1363 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
1364 * nice 1, it will get ~10% less CPU time than another CPU-bound task
1365 * that remained on nice 0.
1366 *
1367 * The "10% effect" is relative and cumulative: from _any_ nice level,
1368 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
Ingo Molnarf9153ee2007-07-16 09:46:30 +02001369 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
1370 * If a task goes up by ~10% and another task goes down by ~10% then
1371 * the relative distance between them is ~25%.)
Ingo Molnardd41f592007-07-09 18:51:59 +02001372 */
1373static const int prio_to_weight[40] = {
Ingo Molnar254753d2007-08-09 11:16:51 +02001374 /* -20 */ 88761, 71755, 56483, 46273, 36291,
1375 /* -15 */ 29154, 23254, 18705, 14949, 11916,
1376 /* -10 */ 9548, 7620, 6100, 4904, 3906,
1377 /* -5 */ 3121, 2501, 1991, 1586, 1277,
1378 /* 0 */ 1024, 820, 655, 526, 423,
1379 /* 5 */ 335, 272, 215, 172, 137,
1380 /* 10 */ 110, 87, 70, 56, 45,
1381 /* 15 */ 36, 29, 23, 18, 15,
Ingo Molnardd41f592007-07-09 18:51:59 +02001382};
1383
Ingo Molnar5714d2d2007-07-16 09:46:31 +02001384/*
1385 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
1386 *
1387 * In cases where the weight does not change often, we can use the
1388 * precalculated inverse to speed up arithmetics by turning divisions
1389 * into multiplications:
1390 */
Ingo Molnardd41f592007-07-09 18:51:59 +02001391static const u32 prio_to_wmult[40] = {
Ingo Molnar254753d2007-08-09 11:16:51 +02001392 /* -20 */ 48388, 59856, 76040, 92818, 118348,
1393 /* -15 */ 147320, 184698, 229616, 287308, 360437,
1394 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
1395 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
1396 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
1397 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
1398 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
1399 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
Ingo Molnardd41f592007-07-09 18:51:59 +02001400};
Peter Williams2dd73a42006-06-27 02:54:34 -07001401
Ingo Molnardd41f592007-07-09 18:51:59 +02001402static void activate_task(struct rq *rq, struct task_struct *p, int wakeup);
1403
1404/*
1405 * runqueue iterator, to support SMP load-balancing between different
1406 * scheduling classes, without having to expose their internal data
1407 * structures to the load-balancing proper:
1408 */
1409struct rq_iterator {
1410 void *arg;
1411 struct task_struct *(*start)(void *);
1412 struct task_struct *(*next)(void *);
1413};
1414
Peter Williamse1d14842007-10-24 18:23:51 +02001415#ifdef CONFIG_SMP
1416static unsigned long
1417balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
1418 unsigned long max_load_move, struct sched_domain *sd,
1419 enum cpu_idle_type idle, int *all_pinned,
1420 int *this_best_prio, struct rq_iterator *iterator);
1421
1422static int
1423iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
1424 struct sched_domain *sd, enum cpu_idle_type idle,
1425 struct rq_iterator *iterator);
Peter Williamse1d14842007-10-24 18:23:51 +02001426#endif
Ingo Molnardd41f592007-07-09 18:51:59 +02001427
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01001428#ifdef CONFIG_CGROUP_CPUACCT
1429static void cpuacct_charge(struct task_struct *tsk, u64 cputime);
1430#else
1431static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
1432#endif
1433
Peter Zijlstra18d95a22008-04-19 19:45:00 +02001434static inline void inc_cpu_load(struct rq *rq, unsigned long load)
1435{
1436 update_load_add(&rq->load, load);
1437}
1438
1439static inline void dec_cpu_load(struct rq *rq, unsigned long load)
1440{
1441 update_load_sub(&rq->load, load);
1442}
1443
Gregory Haskinse7693a32008-01-25 21:08:09 +01001444#ifdef CONFIG_SMP
1445static unsigned long source_load(int cpu, int type);
1446static unsigned long target_load(int cpu, int type);
Gregory Haskinse7693a32008-01-25 21:08:09 +01001447static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001448
Peter Zijlstraa8a51d52008-06-27 13:41:26 +02001449static unsigned long cpu_avg_load_per_task(int cpu)
1450{
1451 struct rq *rq = cpu_rq(cpu);
1452
1453 if (rq->nr_running)
1454 rq->avg_load_per_task = rq->load.weight / rq->nr_running;
1455
1456 return rq->avg_load_per_task;
1457}
1458
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001459#ifdef CONFIG_FAIR_GROUP_SCHED
1460
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001461typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001462
1463/*
1464 * Iterate the full tree, calling @down when first entering a node and @up when
1465 * leaving it for the final time.
1466 */
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001467static void
1468walk_tg_tree(tg_visitor down, tg_visitor up, int cpu, struct sched_domain *sd)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001469{
1470 struct task_group *parent, *child;
1471
1472 rcu_read_lock();
1473 parent = &root_task_group;
1474down:
Peter Zijlstrab6a86c72008-06-27 13:41:18 +02001475 (*down)(parent, cpu, sd);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001476 list_for_each_entry_rcu(child, &parent->children, siblings) {
1477 parent = child;
1478 goto down;
1479
1480up:
1481 continue;
1482 }
Peter Zijlstrab6a86c72008-06-27 13:41:18 +02001483 (*up)(parent, cpu, sd);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001484
1485 child = parent;
1486 parent = parent->parent;
1487 if (parent)
1488 goto up;
1489 rcu_read_unlock();
1490}
1491
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001492static void __set_se_shares(struct sched_entity *se, unsigned long shares);
1493
1494/*
1495 * Calculate and set the cpu's group shares.
1496 */
1497static void
Peter Zijlstrab6a86c72008-06-27 13:41:18 +02001498__update_group_shares_cpu(struct task_group *tg, int cpu,
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001499 unsigned long sd_shares, unsigned long sd_rq_weight)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001500{
1501 int boost = 0;
1502 unsigned long shares;
1503 unsigned long rq_weight;
1504
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001505 if (!tg->se[cpu])
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001506 return;
1507
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001508 rq_weight = tg->cfs_rq[cpu]->load.weight;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001509
1510 /*
1511 * If there are currently no tasks on the cpu pretend there is one of
1512 * average load so that when a new task gets to run here it will not
1513 * get delayed by group starvation.
1514 */
1515 if (!rq_weight) {
1516 boost = 1;
1517 rq_weight = NICE_0_LOAD;
1518 }
1519
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001520 if (unlikely(rq_weight > sd_rq_weight))
1521 rq_weight = sd_rq_weight;
1522
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001523 /*
1524 * \Sum shares * rq_weight
1525 * shares = -----------------------
1526 * \Sum rq_weight
1527 *
1528 */
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001529 shares = (sd_shares * rq_weight) / (sd_rq_weight + 1);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001530
1531 /*
1532 * record the actual number of shares, not the boosted amount.
1533 */
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001534 tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
Peter Zijlstraf1d239f2008-06-27 13:41:38 +02001535 tg->cfs_rq[cpu]->rq_weight = rq_weight;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001536
1537 if (shares < MIN_SHARES)
1538 shares = MIN_SHARES;
1539 else if (shares > MAX_SHARES)
1540 shares = MAX_SHARES;
1541
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001542 __set_se_shares(tg->se[cpu], shares);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001543}
1544
1545/*
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001546 * Re-compute the task group their per cpu shares over the given domain.
1547 * This needs to be done in a bottom-up fashion because the rq weight of a
1548 * parent group depends on the shares of its child groups.
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001549 */
1550static void
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001551tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001552{
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001553 unsigned long rq_weight = 0;
1554 unsigned long shares = 0;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001555 int i;
1556
1557 for_each_cpu_mask(i, sd->span) {
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001558 rq_weight += tg->cfs_rq[i]->load.weight;
1559 shares += tg->cfs_rq[i]->shares;
1560 }
1561
1562 if ((!shares && rq_weight) || shares > tg->shares)
1563 shares = tg->shares;
1564
1565 if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
1566 shares = tg->shares;
1567
Peter Zijlstracd809172008-06-27 13:41:34 +02001568 if (!rq_weight)
1569 rq_weight = cpus_weight(sd->span) * NICE_0_LOAD;
1570
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001571 for_each_cpu_mask(i, sd->span) {
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001572 struct rq *rq = cpu_rq(i);
1573 unsigned long flags;
1574
1575 spin_lock_irqsave(&rq->lock, flags);
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001576 __update_group_shares_cpu(tg, i, shares, rq_weight);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001577 spin_unlock_irqrestore(&rq->lock, flags);
1578 }
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001579}
1580
1581/*
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001582 * Compute the cpu's hierarchical load factor for each task group.
1583 * This needs to be done in a top-down fashion because the load of a child
1584 * group is a fraction of its parents load.
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001585 */
Peter Zijlstrab6a86c72008-06-27 13:41:18 +02001586static void
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001587tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001588{
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001589 unsigned long load;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001590
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001591 if (!tg->parent) {
1592 load = cpu_rq(cpu)->load.weight;
1593 } else {
1594 load = tg->parent->cfs_rq[cpu]->h_load;
1595 load *= tg->cfs_rq[cpu]->shares;
1596 load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
1597 }
1598
1599 tg->cfs_rq[cpu]->h_load = load;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001600}
1601
Peter Zijlstra4d8d5952008-06-27 13:41:19 +02001602static void
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001603tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)
Peter Zijlstra4d8d5952008-06-27 13:41:19 +02001604{
1605}
1606
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001607static void update_shares(struct sched_domain *sd)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001608{
Peter Zijlstra2398f2c2008-06-27 13:41:35 +02001609 u64 now = cpu_clock(raw_smp_processor_id());
1610 s64 elapsed = now - sd->last_update;
1611
1612 if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
1613 sd->last_update = now;
1614 walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
1615 }
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001616}
1617
Peter Zijlstra3e5459b2008-06-27 13:41:24 +02001618static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
1619{
1620 spin_unlock(&rq->lock);
1621 update_shares(sd);
1622 spin_lock(&rq->lock);
1623}
1624
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001625static void update_h_load(int cpu)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001626{
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001627 walk_tg_tree(tg_load_down, tg_nop, cpu, NULL);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001628}
1629
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001630#else
1631
Peter Zijlstrac8cba852008-06-27 13:41:23 +02001632static inline void update_shares(struct sched_domain *sd)
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001633{
1634}
1635
Peter Zijlstra3e5459b2008-06-27 13:41:24 +02001636static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd)
1637{
1638}
1639
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001640#endif
1641
Peter Zijlstra18d95a22008-04-19 19:45:00 +02001642#endif
1643
Vegard Nossum30432092008-06-27 21:35:50 +02001644#ifdef CONFIG_FAIR_GROUP_SCHED
Ingo Molnar34e83e82008-06-27 15:42:36 +02001645static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
1646{
Vegard Nossum30432092008-06-27 21:35:50 +02001647#ifdef CONFIG_SMP
Ingo Molnar34e83e82008-06-27 15:42:36 +02001648 cfs_rq->shares = shares;
1649#endif
1650}
Vegard Nossum30432092008-06-27 21:35:50 +02001651#endif
Ingo Molnar34e83e82008-06-27 15:42:36 +02001652
Ingo Molnardd41f592007-07-09 18:51:59 +02001653#include "sched_stats.h"
Ingo Molnardd41f592007-07-09 18:51:59 +02001654#include "sched_idletask.c"
Ingo Molnar5522d5d2007-10-15 17:00:12 +02001655#include "sched_fair.c"
1656#include "sched_rt.c"
Ingo Molnardd41f592007-07-09 18:51:59 +02001657#ifdef CONFIG_SCHED_DEBUG
1658# include "sched_debug.c"
1659#endif
1660
1661#define sched_class_highest (&rt_sched_class)
Gregory Haskins1f11eb62008-06-04 15:04:05 -04001662#define for_each_class(class) \
1663 for (class = sched_class_highest; class; class = class->next)
Ingo Molnardd41f592007-07-09 18:51:59 +02001664
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001665static void inc_nr_running(struct rq *rq)
Ingo Molnar6363ca52008-05-29 11:28:57 +02001666{
1667 rq->nr_running++;
Ingo Molnar6363ca52008-05-29 11:28:57 +02001668}
1669
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001670static void dec_nr_running(struct rq *rq)
Ingo Molnar9c217242007-08-02 17:41:40 +02001671{
1672 rq->nr_running--;
Ingo Molnar9c217242007-08-02 17:41:40 +02001673}
1674
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001675static void set_load_weight(struct task_struct *p)
1676{
1677 if (task_has_rt_policy(p)) {
Ingo Molnardd41f592007-07-09 18:51:59 +02001678 p->se.load.weight = prio_to_weight[0] * 2;
1679 p->se.load.inv_weight = prio_to_wmult[0] >> 1;
1680 return;
1681 }
1682
1683 /*
1684 * SCHED_IDLE tasks get minimal weight:
1685 */
1686 if (p->policy == SCHED_IDLE) {
1687 p->se.load.weight = WEIGHT_IDLEPRIO;
1688 p->se.load.inv_weight = WMULT_IDLEPRIO;
1689 return;
1690 }
1691
1692 p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO];
1693 p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO];
Ingo Molnar45bf76d2007-07-09 18:51:59 +02001694}
1695
Ingo Molnar8159f872007-08-09 11:16:49 +02001696static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
Ingo Molnar71f8bd42007-07-09 18:51:59 +02001697{
1698 sched_info_queued(p);
Ingo Molnarfd390f62007-08-09 11:16:48 +02001699 p->sched_class->enqueue_task(rq, p, wakeup);
Ingo Molnardd41f592007-07-09 18:51:59 +02001700 p->se.on_rq = 1;
1701}
1702
Ingo Molnar69be72c2007-08-09 11:16:49 +02001703static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
Ingo Molnardd41f592007-07-09 18:51:59 +02001704{
Ingo Molnarf02231e2007-08-09 11:16:48 +02001705 p->sched_class->dequeue_task(rq, p, sleep);
Ingo Molnardd41f592007-07-09 18:51:59 +02001706 p->se.on_rq = 0;
Ingo Molnar71f8bd42007-07-09 18:51:59 +02001707}
1708
1709/*
Ingo Molnardd41f592007-07-09 18:51:59 +02001710 * __normal_prio - return the priority that is based on the static prio
Ingo Molnar71f8bd42007-07-09 18:51:59 +02001711 */
Ingo Molnar14531182007-07-09 18:51:59 +02001712static inline int __normal_prio(struct task_struct *p)
1713{
Ingo Molnardd41f592007-07-09 18:51:59 +02001714 return p->static_prio;
Ingo Molnar14531182007-07-09 18:51:59 +02001715}
1716
1717/*
Ingo Molnarb29739f2006-06-27 02:54:51 -07001718 * Calculate the expected normal priority: i.e. priority
1719 * without taking RT-inheritance into account. Might be
1720 * boosted by interactivity modifiers. Changes upon fork,
1721 * setprio syscalls, and whenever the interactivity
1722 * estimator recalculates.
1723 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07001724static inline int normal_prio(struct task_struct *p)
Ingo Molnarb29739f2006-06-27 02:54:51 -07001725{
1726 int prio;
1727
Ingo Molnare05606d2007-07-09 18:51:59 +02001728 if (task_has_rt_policy(p))
Ingo Molnarb29739f2006-06-27 02:54:51 -07001729 prio = MAX_RT_PRIO-1 - p->rt_priority;
1730 else
1731 prio = __normal_prio(p);
1732 return prio;
1733}
1734
1735/*
1736 * Calculate the current priority, i.e. the priority
1737 * taken into account by the scheduler. This value might
1738 * be boosted by RT tasks, or might be boosted by
1739 * interactivity modifiers. Will be RT if the task got
1740 * RT-boosted. If not then it returns p->normal_prio.
1741 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07001742static int effective_prio(struct task_struct *p)
Ingo Molnarb29739f2006-06-27 02:54:51 -07001743{
1744 p->normal_prio = normal_prio(p);
1745 /*
1746 * If we are RT tasks or we were boosted to RT priority,
1747 * keep the priority unchanged. Otherwise, update priority
1748 * to the normal priority:
1749 */
1750 if (!rt_prio(p->prio))
1751 return p->normal_prio;
1752 return p->prio;
1753}
1754
1755/*
Ingo Molnardd41f592007-07-09 18:51:59 +02001756 * activate_task - move a task to the runqueue.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 */
Ingo Molnardd41f592007-07-09 18:51:59 +02001758static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759{
Matthew Wilcoxd9514f62007-12-06 11:07:07 -05001760 if (task_contributes_to_load(p))
Ingo Molnardd41f592007-07-09 18:51:59 +02001761 rq->nr_uninterruptible--;
1762
Ingo Molnar8159f872007-08-09 11:16:49 +02001763 enqueue_task(rq, p, wakeup);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001764 inc_nr_running(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765}
1766
1767/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 * deactivate_task - remove a task from the runqueue.
1769 */
Ingo Molnar2e1cb742007-08-09 11:16:49 +02001770static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771{
Matthew Wilcoxd9514f62007-12-06 11:07:07 -05001772 if (task_contributes_to_load(p))
Ingo Molnardd41f592007-07-09 18:51:59 +02001773 rq->nr_uninterruptible++;
1774
Ingo Molnar69be72c2007-08-09 11:16:49 +02001775 dequeue_task(rq, p, sleep);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02001776 dec_nr_running(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777}
1778
Linus Torvalds1da177e2005-04-16 15:20:36 -07001779/**
1780 * task_curr - is this task currently executing on a CPU?
1781 * @p: the task in question.
1782 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07001783inline int task_curr(const struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784{
1785 return cpu_curr(task_cpu(p)) == p;
1786}
1787
Ingo Molnardd41f592007-07-09 18:51:59 +02001788static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
1789{
Peter Zijlstra6f505b12008-01-25 21:08:30 +01001790 set_task_rq(p, cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02001791#ifdef CONFIG_SMP
Dmitry Adamushkoce96b5a2007-11-15 20:57:40 +01001792 /*
1793 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
1794 * successfuly executed on another CPU. We must ensure that updates of
1795 * per-task data have been completed by this moment.
1796 */
1797 smp_wmb();
Ingo Molnardd41f592007-07-09 18:51:59 +02001798 task_thread_info(p)->cpu = cpu;
Ingo Molnardd41f592007-07-09 18:51:59 +02001799#endif
Peter Williams2dd73a42006-06-27 02:54:34 -07001800}
1801
Steven Rostedtcb469842008-01-25 21:08:22 +01001802static inline void check_class_changed(struct rq *rq, struct task_struct *p,
1803 const struct sched_class *prev_class,
1804 int oldprio, int running)
1805{
1806 if (prev_class != p->sched_class) {
1807 if (prev_class->switched_from)
1808 prev_class->switched_from(rq, p, running);
1809 p->sched_class->switched_to(rq, p, running);
1810 } else
1811 p->sched_class->prio_changed(rq, p, oldprio, running);
1812}
1813
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814#ifdef CONFIG_SMP
Ingo Molnarc65cc872007-07-09 18:51:58 +02001815
Thomas Gleixnere958b362008-06-04 23:22:32 +02001816/* Used instead of source_load when we know the type == 0 */
1817static unsigned long weighted_cpuload(const int cpu)
1818{
1819 return cpu_rq(cpu)->load.weight;
1820}
1821
Ingo Molnarcc367732007-10-15 17:00:18 +02001822/*
1823 * Is this task likely cache-hot:
1824 */
Gregory Haskinse7693a32008-01-25 21:08:09 +01001825static int
Ingo Molnarcc367732007-10-15 17:00:18 +02001826task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
1827{
1828 s64 delta;
1829
Ingo Molnarf540a602008-03-15 17:10:34 +01001830 /*
1831 * Buddy candidates are cache hot:
1832 */
Ingo Molnard25ce4c2008-03-17 09:36:53 +01001833 if (sched_feat(CACHE_HOT_BUDDY) && (&p->se == cfs_rq_of(&p->se)->next))
Ingo Molnarf540a602008-03-15 17:10:34 +01001834 return 1;
1835
Ingo Molnarcc367732007-10-15 17:00:18 +02001836 if (p->sched_class != &fair_sched_class)
1837 return 0;
1838
Ingo Molnar6bc16652007-10-15 17:00:18 +02001839 if (sysctl_sched_migration_cost == -1)
1840 return 1;
1841 if (sysctl_sched_migration_cost == 0)
1842 return 0;
1843
Ingo Molnarcc367732007-10-15 17:00:18 +02001844 delta = now - p->se.exec_start;
1845
1846 return delta < (s64)sysctl_sched_migration_cost;
1847}
1848
1849
Ingo Molnardd41f592007-07-09 18:51:59 +02001850void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
Ingo Molnarc65cc872007-07-09 18:51:58 +02001851{
Ingo Molnardd41f592007-07-09 18:51:59 +02001852 int old_cpu = task_cpu(p);
1853 struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
Srivatsa Vaddagiri2830cf82007-10-15 17:00:12 +02001854 struct cfs_rq *old_cfsrq = task_cfs_rq(p),
1855 *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu);
Ingo Molnarbbdba7c2007-10-15 17:00:06 +02001856 u64 clock_offset;
Ingo Molnardd41f592007-07-09 18:51:59 +02001857
1858 clock_offset = old_rq->clock - new_rq->clock;
Ingo Molnar6cfb0d52007-08-02 17:41:40 +02001859
1860#ifdef CONFIG_SCHEDSTATS
1861 if (p->se.wait_start)
1862 p->se.wait_start -= clock_offset;
Ingo Molnardd41f592007-07-09 18:51:59 +02001863 if (p->se.sleep_start)
1864 p->se.sleep_start -= clock_offset;
1865 if (p->se.block_start)
1866 p->se.block_start -= clock_offset;
Ingo Molnarcc367732007-10-15 17:00:18 +02001867 if (old_cpu != new_cpu) {
1868 schedstat_inc(p, se.nr_migrations);
1869 if (task_hot(p, old_rq->clock, NULL))
1870 schedstat_inc(p, se.nr_forced2_migrations);
1871 }
Ingo Molnar6cfb0d52007-08-02 17:41:40 +02001872#endif
Srivatsa Vaddagiri2830cf82007-10-15 17:00:12 +02001873 p->se.vruntime -= old_cfsrq->min_vruntime -
1874 new_cfsrq->min_vruntime;
Ingo Molnardd41f592007-07-09 18:51:59 +02001875
1876 __set_task_cpu(p, new_cpu);
Ingo Molnarc65cc872007-07-09 18:51:58 +02001877}
1878
Ingo Molnar70b97a72006-07-03 00:25:42 -07001879struct migration_req {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001880 struct list_head list;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001881
Ingo Molnar36c8b582006-07-03 00:25:41 -07001882 struct task_struct *task;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 int dest_cpu;
1884
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 struct completion done;
Ingo Molnar70b97a72006-07-03 00:25:42 -07001886};
Linus Torvalds1da177e2005-04-16 15:20:36 -07001887
1888/*
1889 * The task's runqueue lock must be held.
1890 * Returns true if you have to wait for migration thread.
1891 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07001892static int
Ingo Molnar70b97a72006-07-03 00:25:42 -07001893migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894{
Ingo Molnar70b97a72006-07-03 00:25:42 -07001895 struct rq *rq = task_rq(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896
1897 /*
1898 * If the task is not on a runqueue (and not running), then
1899 * it is sufficient to simply update the task's cpu field.
1900 */
Ingo Molnardd41f592007-07-09 18:51:59 +02001901 if (!p->se.on_rq && !task_running(rq, p)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001902 set_task_cpu(p, dest_cpu);
1903 return 0;
1904 }
1905
1906 init_completion(&req->done);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 req->task = p;
1908 req->dest_cpu = dest_cpu;
1909 list_add(&req->list, &rq->migration_queue);
Ingo Molnar48f24c42006-07-03 00:25:40 -07001910
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 return 1;
1912}
1913
1914/*
1915 * wait_task_inactive - wait for a thread to unschedule.
1916 *
1917 * The caller must ensure that the task *will* unschedule sometime soon,
1918 * else this function might spin for a *long* time. This function can't
1919 * be called with interrupts off, or it may introduce deadlock with
1920 * smp_call_function() if an IPI is sent by the same process we are
1921 * waiting to become inactive.
1922 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07001923void wait_task_inactive(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001924{
1925 unsigned long flags;
Ingo Molnardd41f592007-07-09 18:51:59 +02001926 int running, on_rq;
Ingo Molnar70b97a72006-07-03 00:25:42 -07001927 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001928
Andi Kleen3a5c3592007-10-15 17:00:14 +02001929 for (;;) {
1930 /*
1931 * We do the initial early heuristics without holding
1932 * any task-queue locks at all. We'll only try to get
1933 * the runqueue lock when things look like they will
1934 * work out!
1935 */
1936 rq = task_rq(p);
Linus Torvaldsfa490cf2007-06-18 09:34:40 -07001937
Andi Kleen3a5c3592007-10-15 17:00:14 +02001938 /*
1939 * If the task is actively running on another CPU
1940 * still, just relax and busy-wait without holding
1941 * any locks.
1942 *
1943 * NOTE! Since we don't hold any locks, it's not
1944 * even sure that "rq" stays as the right runqueue!
1945 * But we don't care, since "task_running()" will
1946 * return false if the runqueue has changed and p
1947 * is actually now running somewhere else!
1948 */
1949 while (task_running(rq, p))
1950 cpu_relax();
Linus Torvaldsfa490cf2007-06-18 09:34:40 -07001951
Andi Kleen3a5c3592007-10-15 17:00:14 +02001952 /*
1953 * Ok, time to look more closely! We need the rq
1954 * lock now, to be *sure*. If we're wrong, we'll
1955 * just go back and repeat.
1956 */
1957 rq = task_rq_lock(p, &flags);
1958 running = task_running(rq, p);
1959 on_rq = p->se.on_rq;
1960 task_rq_unlock(rq, &flags);
Linus Torvaldsfa490cf2007-06-18 09:34:40 -07001961
Andi Kleen3a5c3592007-10-15 17:00:14 +02001962 /*
1963 * Was it really running after all now that we
1964 * checked with the proper locks actually held?
1965 *
1966 * Oops. Go back and try again..
1967 */
1968 if (unlikely(running)) {
1969 cpu_relax();
1970 continue;
1971 }
1972
1973 /*
1974 * It's not enough that it's not actively running,
1975 * it must be off the runqueue _entirely_, and not
1976 * preempted!
1977 *
1978 * So if it wa still runnable (but just not actively
1979 * running right now), it's preempted, and we should
1980 * yield - it could be a while.
1981 */
1982 if (unlikely(on_rq)) {
1983 schedule_timeout_uninterruptible(1);
1984 continue;
1985 }
1986
1987 /*
1988 * Ahh, all good. It wasn't running, and it wasn't
1989 * runnable, which means that it will never become
1990 * running in the future either. We're all done!
1991 */
1992 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001993 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994}
1995
1996/***
1997 * kick_process - kick a running thread to enter/exit the kernel
1998 * @p: the to-be-kicked thread
1999 *
2000 * Cause a process which is running on another CPU to enter
2001 * kernel-mode, without any delay. (to get signals handled.)
2002 *
2003 * NOTE: this function doesnt have to take the runqueue lock,
2004 * because all it wants to ensure is that the remote task enters
2005 * the kernel. If the IPI races and the task has been migrated
2006 * to another CPU then no harm is done and the purpose has been
2007 * achieved as well.
2008 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07002009void kick_process(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002010{
2011 int cpu;
2012
2013 preempt_disable();
2014 cpu = task_cpu(p);
2015 if ((cpu != smp_processor_id()) && task_curr(p))
2016 smp_send_reschedule(cpu);
2017 preempt_enable();
2018}
2019
2020/*
Peter Williams2dd73a42006-06-27 02:54:34 -07002021 * Return a low guess at the load of a migration-source cpu weighted
2022 * according to the scheduling class and "nice" value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002023 *
2024 * We want to under-estimate the load of migration sources, to
2025 * balance conservatively.
2026 */
Alexey Dobriyana9957442007-10-15 17:00:13 +02002027static unsigned long source_load(int cpu, int type)
Con Kolivasb9104722005-11-08 21:38:55 -08002028{
Ingo Molnar70b97a72006-07-03 00:25:42 -07002029 struct rq *rq = cpu_rq(cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02002030 unsigned long total = weighted_cpuload(cpu);
Nick Piggina2000572006-02-10 01:51:02 -08002031
Peter Zijlstra93b75212008-06-27 13:41:33 +02002032 if (type == 0 || !sched_feat(LB_BIAS))
Ingo Molnardd41f592007-07-09 18:51:59 +02002033 return total;
Peter Williams2dd73a42006-06-27 02:54:34 -07002034
Ingo Molnardd41f592007-07-09 18:51:59 +02002035 return min(rq->cpu_load[type-1], total);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002036}
2037
2038/*
Peter Williams2dd73a42006-06-27 02:54:34 -07002039 * Return a high guess at the load of a migration-target cpu weighted
2040 * according to the scheduling class and "nice" value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002041 */
Alexey Dobriyana9957442007-10-15 17:00:13 +02002042static unsigned long target_load(int cpu, int type)
Con Kolivasb9104722005-11-08 21:38:55 -08002043{
Ingo Molnar70b97a72006-07-03 00:25:42 -07002044 struct rq *rq = cpu_rq(cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02002045 unsigned long total = weighted_cpuload(cpu);
Nick Piggina2000572006-02-10 01:51:02 -08002046
Peter Zijlstra93b75212008-06-27 13:41:33 +02002047 if (type == 0 || !sched_feat(LB_BIAS))
Ingo Molnardd41f592007-07-09 18:51:59 +02002048 return total;
Peter Williams2dd73a42006-06-27 02:54:34 -07002049
Ingo Molnardd41f592007-07-09 18:51:59 +02002050 return max(rq->cpu_load[type-1], total);
Peter Williams2dd73a42006-06-27 02:54:34 -07002051}
2052
2053/*
Nick Piggin147cbb42005-06-25 14:57:19 -07002054 * find_idlest_group finds and returns the least busy CPU group within the
2055 * domain.
2056 */
2057static struct sched_group *
2058find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
2059{
2060 struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups;
2061 unsigned long min_load = ULONG_MAX, this_load = 0;
2062 int load_idx = sd->forkexec_idx;
2063 int imbalance = 100 + (sd->imbalance_pct-100)/2;
2064
2065 do {
2066 unsigned long load, avg_load;
2067 int local_group;
2068 int i;
2069
M.Baris Demirayda5a5522005-09-10 00:26:09 -07002070 /* Skip over this group if it has no CPUs allowed */
2071 if (!cpus_intersects(group->cpumask, p->cpus_allowed))
Andi Kleen3a5c3592007-10-15 17:00:14 +02002072 continue;
M.Baris Demirayda5a5522005-09-10 00:26:09 -07002073
Nick Piggin147cbb42005-06-25 14:57:19 -07002074 local_group = cpu_isset(this_cpu, group->cpumask);
Nick Piggin147cbb42005-06-25 14:57:19 -07002075
2076 /* Tally up the load of all CPUs in the group */
2077 avg_load = 0;
2078
2079 for_each_cpu_mask(i, group->cpumask) {
2080 /* Bias balancing toward cpus of our domain */
2081 if (local_group)
2082 load = source_load(i, load_idx);
2083 else
2084 load = target_load(i, load_idx);
2085
2086 avg_load += load;
2087 }
2088
2089 /* Adjust by relative CPU power of the group */
Eric Dumazet5517d862007-05-08 00:32:57 -07002090 avg_load = sg_div_cpu_power(group,
2091 avg_load * SCHED_LOAD_SCALE);
Nick Piggin147cbb42005-06-25 14:57:19 -07002092
2093 if (local_group) {
2094 this_load = avg_load;
2095 this = group;
2096 } else if (avg_load < min_load) {
2097 min_load = avg_load;
2098 idlest = group;
2099 }
Andi Kleen3a5c3592007-10-15 17:00:14 +02002100 } while (group = group->next, group != sd->groups);
Nick Piggin147cbb42005-06-25 14:57:19 -07002101
2102 if (!idlest || 100*this_load < imbalance*min_load)
2103 return NULL;
2104 return idlest;
2105}
2106
2107/*
Satoru Takeuchi0feaece2006-10-03 01:14:10 -07002108 * find_idlest_cpu - find the idlest cpu among the cpus in group.
Nick Piggin147cbb42005-06-25 14:57:19 -07002109 */
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07002110static int
Mike Travis7c16ec52008-04-04 18:11:11 -07002111find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu,
2112 cpumask_t *tmp)
Nick Piggin147cbb42005-06-25 14:57:19 -07002113{
2114 unsigned long load, min_load = ULONG_MAX;
2115 int idlest = -1;
2116 int i;
2117
M.Baris Demirayda5a5522005-09-10 00:26:09 -07002118 /* Traverse only the allowed CPUs */
Mike Travis7c16ec52008-04-04 18:11:11 -07002119 cpus_and(*tmp, group->cpumask, p->cpus_allowed);
M.Baris Demirayda5a5522005-09-10 00:26:09 -07002120
Mike Travis7c16ec52008-04-04 18:11:11 -07002121 for_each_cpu_mask(i, *tmp) {
Peter Williams2dd73a42006-06-27 02:54:34 -07002122 load = weighted_cpuload(i);
Nick Piggin147cbb42005-06-25 14:57:19 -07002123
2124 if (load < min_load || (load == min_load && i == this_cpu)) {
2125 min_load = load;
2126 idlest = i;
2127 }
2128 }
2129
2130 return idlest;
2131}
2132
Nick Piggin476d1392005-06-25 14:57:29 -07002133/*
2134 * sched_balance_self: balance the current task (running on cpu) in domains
2135 * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
2136 * SD_BALANCE_EXEC.
2137 *
2138 * Balance, ie. select the least loaded group.
2139 *
2140 * Returns the target CPU number, or the same CPU if no balancing is needed.
2141 *
2142 * preempt must be disabled.
2143 */
2144static int sched_balance_self(int cpu, int flag)
2145{
2146 struct task_struct *t = current;
2147 struct sched_domain *tmp, *sd = NULL;
Nick Piggin147cbb42005-06-25 14:57:19 -07002148
Chen, Kenneth Wc96d1452006-06-27 02:54:28 -07002149 for_each_domain(cpu, tmp) {
Ingo Molnar9761eea2007-07-09 18:52:00 +02002150 /*
2151 * If power savings logic is enabled for a domain, stop there.
2152 */
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07002153 if (tmp->flags & SD_POWERSAVINGS_BALANCE)
2154 break;
Nick Piggin476d1392005-06-25 14:57:29 -07002155 if (tmp->flags & flag)
2156 sd = tmp;
Chen, Kenneth Wc96d1452006-06-27 02:54:28 -07002157 }
Nick Piggin476d1392005-06-25 14:57:29 -07002158
Peter Zijlstra039a1c42008-06-27 13:41:25 +02002159 if (sd)
2160 update_shares(sd);
2161
Nick Piggin476d1392005-06-25 14:57:29 -07002162 while (sd) {
Mike Travis7c16ec52008-04-04 18:11:11 -07002163 cpumask_t span, tmpmask;
Nick Piggin476d1392005-06-25 14:57:29 -07002164 struct sched_group *group;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07002165 int new_cpu, weight;
2166
2167 if (!(sd->flags & flag)) {
2168 sd = sd->child;
2169 continue;
2170 }
Nick Piggin476d1392005-06-25 14:57:29 -07002171
2172 span = sd->span;
2173 group = find_idlest_group(sd, t, cpu);
Siddha, Suresh B1a848872006-10-03 01:14:08 -07002174 if (!group) {
2175 sd = sd->child;
2176 continue;
2177 }
Nick Piggin476d1392005-06-25 14:57:29 -07002178
Mike Travis7c16ec52008-04-04 18:11:11 -07002179 new_cpu = find_idlest_cpu(group, t, cpu, &tmpmask);
Siddha, Suresh B1a848872006-10-03 01:14:08 -07002180 if (new_cpu == -1 || new_cpu == cpu) {
2181 /* Now try balancing at a lower domain level of cpu */
2182 sd = sd->child;
2183 continue;
2184 }
Nick Piggin476d1392005-06-25 14:57:29 -07002185
Siddha, Suresh B1a848872006-10-03 01:14:08 -07002186 /* Now try balancing at a lower domain level of new_cpu */
Nick Piggin476d1392005-06-25 14:57:29 -07002187 cpu = new_cpu;
Nick Piggin476d1392005-06-25 14:57:29 -07002188 sd = NULL;
2189 weight = cpus_weight(span);
2190 for_each_domain(cpu, tmp) {
2191 if (weight <= cpus_weight(tmp->span))
2192 break;
2193 if (tmp->flags & flag)
2194 sd = tmp;
2195 }
2196 /* while loop will break here if sd == NULL */
2197 }
2198
2199 return cpu;
2200}
2201
2202#endif /* CONFIG_SMP */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002203
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204/***
2205 * try_to_wake_up - wake up a thread
2206 * @p: the to-be-woken-up thread
2207 * @state: the mask of task states that can be woken
2208 * @sync: do a synchronous wakeup?
2209 *
2210 * Put it on the run-queue if it's not already there. The "current"
2211 * thread is always on the run-queue (except when the actual
2212 * re-schedule is in progress), and as such you're allowed to do
2213 * the simpler "current->state = TASK_RUNNING" to mark yourself
2214 * runnable without the overhead of this.
2215 *
2216 * returns failure only if the task is already active.
2217 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07002218static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002219{
Ingo Molnarcc367732007-10-15 17:00:18 +02002220 int cpu, orig_cpu, this_cpu, success = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002221 unsigned long flags;
2222 long old_state;
Ingo Molnar70b97a72006-07-03 00:25:42 -07002223 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002224
Ingo Molnarb85d0662008-03-16 20:03:22 +01002225 if (!sched_feat(SYNC_WAKEUPS))
2226 sync = 0;
2227
Peter Zijlstra2398f2c2008-06-27 13:41:35 +02002228#ifdef CONFIG_SMP
2229 if (sched_feat(LB_WAKEUP_UPDATE)) {
2230 struct sched_domain *sd;
2231
2232 this_cpu = raw_smp_processor_id();
2233 cpu = task_cpu(p);
2234
2235 for_each_domain(this_cpu, sd) {
2236 if (cpu_isset(cpu, sd->span)) {
2237 update_shares(sd);
2238 break;
2239 }
2240 }
2241 }
2242#endif
2243
Linus Torvalds04e2f172008-02-23 18:05:03 -08002244 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 rq = task_rq_lock(p, &flags);
2246 old_state = p->state;
2247 if (!(old_state & state))
2248 goto out;
2249
Ingo Molnardd41f592007-07-09 18:51:59 +02002250 if (p->se.on_rq)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002251 goto out_running;
2252
2253 cpu = task_cpu(p);
Ingo Molnarcc367732007-10-15 17:00:18 +02002254 orig_cpu = cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 this_cpu = smp_processor_id();
2256
2257#ifdef CONFIG_SMP
2258 if (unlikely(task_running(rq, p)))
2259 goto out_activate;
2260
Dmitry Adamushko5d2f5a62008-01-25 21:08:21 +01002261 cpu = p->sched_class->select_task_rq(p, sync);
2262 if (cpu != orig_cpu) {
2263 set_task_cpu(p, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264 task_rq_unlock(rq, &flags);
2265 /* might preempt at this point */
2266 rq = task_rq_lock(p, &flags);
2267 old_state = p->state;
2268 if (!(old_state & state))
2269 goto out;
Ingo Molnardd41f592007-07-09 18:51:59 +02002270 if (p->se.on_rq)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002271 goto out_running;
2272
2273 this_cpu = smp_processor_id();
2274 cpu = task_cpu(p);
2275 }
2276
Gregory Haskinse7693a32008-01-25 21:08:09 +01002277#ifdef CONFIG_SCHEDSTATS
2278 schedstat_inc(rq, ttwu_count);
2279 if (cpu == this_cpu)
2280 schedstat_inc(rq, ttwu_local);
2281 else {
2282 struct sched_domain *sd;
2283 for_each_domain(this_cpu, sd) {
2284 if (cpu_isset(cpu, sd->span)) {
2285 schedstat_inc(sd, ttwu_wake_remote);
2286 break;
2287 }
2288 }
2289 }
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02002290#endif /* CONFIG_SCHEDSTATS */
Gregory Haskinse7693a32008-01-25 21:08:09 +01002291
Linus Torvalds1da177e2005-04-16 15:20:36 -07002292out_activate:
2293#endif /* CONFIG_SMP */
Ingo Molnarcc367732007-10-15 17:00:18 +02002294 schedstat_inc(p, se.nr_wakeups);
2295 if (sync)
2296 schedstat_inc(p, se.nr_wakeups_sync);
2297 if (orig_cpu != cpu)
2298 schedstat_inc(p, se.nr_wakeups_migrate);
2299 if (cpu == this_cpu)
2300 schedstat_inc(p, se.nr_wakeups_local);
2301 else
2302 schedstat_inc(p, se.nr_wakeups_remote);
Ingo Molnar2daa3572007-08-09 11:16:51 +02002303 update_rq_clock(rq);
Ingo Molnardd41f592007-07-09 18:51:59 +02002304 activate_task(rq, p, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 success = 1;
2306
2307out_running:
Ingo Molnar4ae7d5c2008-03-19 01:42:00 +01002308 check_preempt_curr(rq, p);
2309
Linus Torvalds1da177e2005-04-16 15:20:36 -07002310 p->state = TASK_RUNNING;
Steven Rostedt9a897c52008-01-25 21:08:22 +01002311#ifdef CONFIG_SMP
2312 if (p->sched_class->task_wake_up)
2313 p->sched_class->task_wake_up(rq, p);
2314#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002315out:
2316 task_rq_unlock(rq, &flags);
2317
2318 return success;
2319}
2320
Harvey Harrison7ad5b3a2008-02-08 04:19:53 -08002321int wake_up_process(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002322{
Matthew Wilcoxd9514f62007-12-06 11:07:07 -05002323 return try_to_wake_up(p, TASK_ALL, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002324}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002325EXPORT_SYMBOL(wake_up_process);
2326
Harvey Harrison7ad5b3a2008-02-08 04:19:53 -08002327int wake_up_state(struct task_struct *p, unsigned int state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002328{
2329 return try_to_wake_up(p, state, 0);
2330}
2331
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332/*
2333 * Perform scheduler related setup for a newly forked process p.
2334 * p is forked by current.
Ingo Molnardd41f592007-07-09 18:51:59 +02002335 *
2336 * __sched_fork() is basic setup used by init_idle() too:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002337 */
Ingo Molnardd41f592007-07-09 18:51:59 +02002338static void __sched_fork(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002339{
Ingo Molnardd41f592007-07-09 18:51:59 +02002340 p->se.exec_start = 0;
2341 p->se.sum_exec_runtime = 0;
Ingo Molnarf6cf8912007-08-28 12:53:24 +02002342 p->se.prev_sum_exec_runtime = 0;
Ingo Molnar4ae7d5c2008-03-19 01:42:00 +01002343 p->se.last_wakeup = 0;
2344 p->se.avg_overlap = 0;
Ingo Molnar6cfb0d52007-08-02 17:41:40 +02002345
2346#ifdef CONFIG_SCHEDSTATS
2347 p->se.wait_start = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02002348 p->se.sum_sleep_runtime = 0;
2349 p->se.sleep_start = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02002350 p->se.block_start = 0;
2351 p->se.sleep_max = 0;
2352 p->se.block_max = 0;
2353 p->se.exec_max = 0;
Ingo Molnareba1ed42007-10-15 17:00:02 +02002354 p->se.slice_max = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02002355 p->se.wait_max = 0;
Ingo Molnar6cfb0d52007-08-02 17:41:40 +02002356#endif
Nick Piggin476d1392005-06-25 14:57:29 -07002357
Peter Zijlstrafa717062008-01-25 21:08:27 +01002358 INIT_LIST_HEAD(&p->rt.run_list);
Ingo Molnardd41f592007-07-09 18:51:59 +02002359 p->se.on_rq = 0;
Peter Zijlstra4a55bd52008-04-19 19:45:00 +02002360 INIT_LIST_HEAD(&p->se.group_node);
Nick Piggin476d1392005-06-25 14:57:29 -07002361
Avi Kivitye107be32007-07-26 13:40:43 +02002362#ifdef CONFIG_PREEMPT_NOTIFIERS
2363 INIT_HLIST_HEAD(&p->preempt_notifiers);
2364#endif
2365
Linus Torvalds1da177e2005-04-16 15:20:36 -07002366 /*
2367 * We mark the process as running here, but have not actually
2368 * inserted it onto the runqueue yet. This guarantees that
2369 * nobody will actually run it, and a signal or other external
2370 * event cannot wake it up and insert it on the runqueue either.
2371 */
2372 p->state = TASK_RUNNING;
Ingo Molnardd41f592007-07-09 18:51:59 +02002373}
2374
2375/*
2376 * fork()/clone()-time setup:
2377 */
2378void sched_fork(struct task_struct *p, int clone_flags)
2379{
2380 int cpu = get_cpu();
2381
2382 __sched_fork(p);
2383
2384#ifdef CONFIG_SMP
2385 cpu = sched_balance_self(cpu, SD_BALANCE_FORK);
2386#endif
Ingo Molnar02e4bac2007-10-15 17:00:11 +02002387 set_task_cpu(p, cpu);
Ingo Molnarb29739f2006-06-27 02:54:51 -07002388
2389 /*
2390 * Make sure we do not leak PI boosting priority to the child:
2391 */
2392 p->prio = current->normal_prio;
Hiroshi Shimamoto2ddbf952007-10-15 17:00:11 +02002393 if (!rt_prio(p->prio))
2394 p->sched_class = &fair_sched_class;
Ingo Molnarb29739f2006-06-27 02:54:51 -07002395
Chandra Seetharaman52f17b62006-07-14 00:24:38 -07002396#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
Ingo Molnardd41f592007-07-09 18:51:59 +02002397 if (likely(sched_info_on()))
Chandra Seetharaman52f17b62006-07-14 00:24:38 -07002398 memset(&p->sched_info, 0, sizeof(p->sched_info));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002399#endif
Chen, Kenneth Wd6077cb2006-02-14 13:53:10 -08002400#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
Nick Piggin4866cde2005-06-25 14:57:23 -07002401 p->oncpu = 0;
2402#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002403#ifdef CONFIG_PREEMPT
Nick Piggin4866cde2005-06-25 14:57:23 -07002404 /* Want to start with kernel preemption disabled. */
Al Viroa1261f52005-11-13 16:06:55 -08002405 task_thread_info(p)->preempt_count = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002406#endif
Nick Piggin476d1392005-06-25 14:57:29 -07002407 put_cpu();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002408}
2409
2410/*
2411 * wake_up_new_task - wake up a newly created task for the first time.
2412 *
2413 * This function will do some initial scheduler statistics housekeeping
2414 * that must be done for every newly created context, then puts the task
2415 * on the runqueue and wakes it.
2416 */
Harvey Harrison7ad5b3a2008-02-08 04:19:53 -08002417void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002418{
2419 unsigned long flags;
Ingo Molnardd41f592007-07-09 18:51:59 +02002420 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002421
2422 rq = task_rq_lock(p, &flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002423 BUG_ON(p->state != TASK_RUNNING);
Ingo Molnara8e504d2007-08-09 11:16:47 +02002424 update_rq_clock(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002425
2426 p->prio = effective_prio(p);
2427
Srivatsa Vaddagirib9dca1e2007-10-17 16:55:11 +02002428 if (!p->sched_class->task_new || !current->se.on_rq) {
Ingo Molnardd41f592007-07-09 18:51:59 +02002429 activate_task(rq, p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002430 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002431 /*
Ingo Molnardd41f592007-07-09 18:51:59 +02002432 * Let the scheduling class do new task startup
2433 * management (if any):
Linus Torvalds1da177e2005-04-16 15:20:36 -07002434 */
Ingo Molnaree0827d2007-08-09 11:16:49 +02002435 p->sched_class->task_new(rq, p);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02002436 inc_nr_running(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437 }
Ingo Molnardd41f592007-07-09 18:51:59 +02002438 check_preempt_curr(rq, p);
Steven Rostedt9a897c52008-01-25 21:08:22 +01002439#ifdef CONFIG_SMP
2440 if (p->sched_class->task_wake_up)
2441 p->sched_class->task_wake_up(rq, p);
2442#endif
Ingo Molnardd41f592007-07-09 18:51:59 +02002443 task_rq_unlock(rq, &flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002444}
2445
Avi Kivitye107be32007-07-26 13:40:43 +02002446#ifdef CONFIG_PREEMPT_NOTIFIERS
2447
2448/**
Randy Dunlap421cee22007-07-31 00:37:50 -07002449 * preempt_notifier_register - tell me when current is being being preempted & rescheduled
2450 * @notifier: notifier struct to register
Avi Kivitye107be32007-07-26 13:40:43 +02002451 */
2452void preempt_notifier_register(struct preempt_notifier *notifier)
2453{
2454 hlist_add_head(&notifier->link, &current->preempt_notifiers);
2455}
2456EXPORT_SYMBOL_GPL(preempt_notifier_register);
2457
2458/**
2459 * preempt_notifier_unregister - no longer interested in preemption notifications
Randy Dunlap421cee22007-07-31 00:37:50 -07002460 * @notifier: notifier struct to unregister
Avi Kivitye107be32007-07-26 13:40:43 +02002461 *
2462 * This is safe to call from within a preemption notifier.
2463 */
2464void preempt_notifier_unregister(struct preempt_notifier *notifier)
2465{
2466 hlist_del(&notifier->link);
2467}
2468EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
2469
2470static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
2471{
2472 struct preempt_notifier *notifier;
2473 struct hlist_node *node;
2474
2475 hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
2476 notifier->ops->sched_in(notifier, raw_smp_processor_id());
2477}
2478
2479static void
2480fire_sched_out_preempt_notifiers(struct task_struct *curr,
2481 struct task_struct *next)
2482{
2483 struct preempt_notifier *notifier;
2484 struct hlist_node *node;
2485
2486 hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
2487 notifier->ops->sched_out(notifier, next);
2488}
2489
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02002490#else /* !CONFIG_PREEMPT_NOTIFIERS */
Avi Kivitye107be32007-07-26 13:40:43 +02002491
2492static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
2493{
2494}
2495
2496static void
2497fire_sched_out_preempt_notifiers(struct task_struct *curr,
2498 struct task_struct *next)
2499{
2500}
2501
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02002502#endif /* CONFIG_PREEMPT_NOTIFIERS */
Avi Kivitye107be32007-07-26 13:40:43 +02002503
Linus Torvalds1da177e2005-04-16 15:20:36 -07002504/**
Nick Piggin4866cde2005-06-25 14:57:23 -07002505 * prepare_task_switch - prepare to switch tasks
2506 * @rq: the runqueue preparing to switch
Randy Dunlap421cee22007-07-31 00:37:50 -07002507 * @prev: the current task that is being switched out
Nick Piggin4866cde2005-06-25 14:57:23 -07002508 * @next: the task we are going to switch to.
2509 *
2510 * This is called with the rq lock held and interrupts off. It must
2511 * be paired with a subsequent finish_task_switch after the context
2512 * switch.
2513 *
2514 * prepare_task_switch sets up locking and calls architecture specific
2515 * hooks.
2516 */
Avi Kivitye107be32007-07-26 13:40:43 +02002517static inline void
2518prepare_task_switch(struct rq *rq, struct task_struct *prev,
2519 struct task_struct *next)
Nick Piggin4866cde2005-06-25 14:57:23 -07002520{
Avi Kivitye107be32007-07-26 13:40:43 +02002521 fire_sched_out_preempt_notifiers(prev, next);
Nick Piggin4866cde2005-06-25 14:57:23 -07002522 prepare_lock_switch(rq, next);
2523 prepare_arch_switch(next);
2524}
2525
2526/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002527 * finish_task_switch - clean up after a task-switch
Jeff Garzik344baba2005-09-07 01:15:17 -04002528 * @rq: runqueue associated with task-switch
Linus Torvalds1da177e2005-04-16 15:20:36 -07002529 * @prev: the thread we just switched away from.
2530 *
Nick Piggin4866cde2005-06-25 14:57:23 -07002531 * finish_task_switch must be called after the context switch, paired
2532 * with a prepare_task_switch call before the context switch.
2533 * finish_task_switch will reconcile locking set up by prepare_task_switch,
2534 * and do any other architecture-specific cleanup actions.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002535 *
2536 * Note that we may have delayed dropping an mm in context_switch(). If
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01002537 * so, we finish that here outside of the runqueue lock. (Doing it
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 * with the lock held can cause deadlocks; see schedule() for
2539 * details.)
2540 */
Alexey Dobriyana9957442007-10-15 17:00:13 +02002541static void finish_task_switch(struct rq *rq, struct task_struct *prev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002542 __releases(rq->lock)
2543{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002544 struct mm_struct *mm = rq->prev_mm;
Oleg Nesterov55a101f2006-09-29 02:01:10 -07002545 long prev_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002546
2547 rq->prev_mm = NULL;
2548
2549 /*
2550 * A task struct has one reference for the use as "current".
Oleg Nesterovc394cc92006-09-29 02:01:11 -07002551 * If a task dies, then it sets TASK_DEAD in tsk->state and calls
Oleg Nesterov55a101f2006-09-29 02:01:10 -07002552 * schedule one last time. The schedule call will never return, and
2553 * the scheduled task must drop that reference.
Oleg Nesterovc394cc92006-09-29 02:01:11 -07002554 * The test for TASK_DEAD must occur while the runqueue locks are
Linus Torvalds1da177e2005-04-16 15:20:36 -07002555 * still held, otherwise prev could be scheduled on another cpu, die
2556 * there before we look at prev->state, and then the reference would
2557 * be dropped twice.
2558 * Manfred Spraul <manfred@colorfullife.com>
2559 */
Oleg Nesterov55a101f2006-09-29 02:01:10 -07002560 prev_state = prev->state;
Nick Piggin4866cde2005-06-25 14:57:23 -07002561 finish_arch_switch(prev);
2562 finish_lock_switch(rq, prev);
Steven Rostedt9a897c52008-01-25 21:08:22 +01002563#ifdef CONFIG_SMP
2564 if (current->sched_class->post_schedule)
2565 current->sched_class->post_schedule(rq);
2566#endif
Steven Rostedte8fa1362008-01-25 21:08:05 +01002567
Avi Kivitye107be32007-07-26 13:40:43 +02002568 fire_sched_in_preempt_notifiers(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002569 if (mm)
2570 mmdrop(mm);
Oleg Nesterovc394cc92006-09-29 02:01:11 -07002571 if (unlikely(prev_state == TASK_DEAD)) {
bibo maoc6fd91f2006-03-26 01:38:20 -08002572 /*
2573 * Remove function-return probe instances associated with this
2574 * task and put them back on the free list.
Ingo Molnar9761eea2007-07-09 18:52:00 +02002575 */
bibo maoc6fd91f2006-03-26 01:38:20 -08002576 kprobe_flush_task(prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002577 put_task_struct(prev);
bibo maoc6fd91f2006-03-26 01:38:20 -08002578 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002579}
2580
2581/**
2582 * schedule_tail - first thing a freshly forked thread must call.
2583 * @prev: the thread we just switched away from.
2584 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07002585asmlinkage void schedule_tail(struct task_struct *prev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002586 __releases(rq->lock)
2587{
Ingo Molnar70b97a72006-07-03 00:25:42 -07002588 struct rq *rq = this_rq();
2589
Nick Piggin4866cde2005-06-25 14:57:23 -07002590 finish_task_switch(rq, prev);
2591#ifdef __ARCH_WANT_UNLOCKED_CTXSW
2592 /* In this case, finish_task_switch does not reenable preemption */
2593 preempt_enable();
2594#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002595 if (current->set_child_tid)
Pavel Emelyanovb4888932007-10-18 23:40:14 -07002596 put_user(task_pid_vnr(current), current->set_child_tid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002597}
2598
2599/*
2600 * context_switch - switch to the new MM and the new
2601 * thread's register state.
2602 */
Ingo Molnardd41f592007-07-09 18:51:59 +02002603static inline void
Ingo Molnar70b97a72006-07-03 00:25:42 -07002604context_switch(struct rq *rq, struct task_struct *prev,
Ingo Molnar36c8b582006-07-03 00:25:41 -07002605 struct task_struct *next)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002606{
Ingo Molnardd41f592007-07-09 18:51:59 +02002607 struct mm_struct *mm, *oldmm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002608
Avi Kivitye107be32007-07-26 13:40:43 +02002609 prepare_task_switch(rq, prev, next);
Ingo Molnardd41f592007-07-09 18:51:59 +02002610 mm = next->mm;
2611 oldmm = prev->active_mm;
Zachary Amsden9226d122007-02-13 13:26:21 +01002612 /*
2613 * For paravirt, this is coupled with an exit in switch_to to
2614 * combine the page table reload and the switch backend into
2615 * one hypercall.
2616 */
2617 arch_enter_lazy_cpu_mode();
2618
Ingo Molnardd41f592007-07-09 18:51:59 +02002619 if (unlikely(!mm)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002620 next->active_mm = oldmm;
2621 atomic_inc(&oldmm->mm_count);
2622 enter_lazy_tlb(oldmm, next);
2623 } else
2624 switch_mm(oldmm, mm, next);
2625
Ingo Molnardd41f592007-07-09 18:51:59 +02002626 if (unlikely(!prev->mm)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002627 prev->active_mm = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002628 rq->prev_mm = oldmm;
2629 }
Ingo Molnar3a5f5e42006-07-14 00:24:27 -07002630 /*
2631 * Since the runqueue lock will be released by the next
2632 * task (which is an invalid locking op but in the case
2633 * of the scheduler it's an obvious special-case), so we
2634 * do an early lockdep release here:
2635 */
2636#ifndef __ARCH_WANT_UNLOCKED_CTXSW
Ingo Molnar8a25d5d2006-07-03 00:24:54 -07002637 spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
Ingo Molnar3a5f5e42006-07-14 00:24:27 -07002638#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002639
2640 /* Here we just switch the register state and the stack. */
2641 switch_to(prev, next, prev);
2642
Ingo Molnardd41f592007-07-09 18:51:59 +02002643 barrier();
2644 /*
2645 * this_rq must be evaluated again because prev may have moved
2646 * CPUs since it called schedule(), thus the 'rq' on its stack
2647 * frame will be invalid.
2648 */
2649 finish_task_switch(this_rq(), prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002650}
2651
2652/*
2653 * nr_running, nr_uninterruptible and nr_context_switches:
2654 *
2655 * externally visible scheduler statistics: current number of runnable
2656 * threads, current number of uninterruptible-sleeping threads, total
2657 * number of context switches performed since bootup.
2658 */
2659unsigned long nr_running(void)
2660{
2661 unsigned long i, sum = 0;
2662
2663 for_each_online_cpu(i)
2664 sum += cpu_rq(i)->nr_running;
2665
2666 return sum;
2667}
2668
2669unsigned long nr_uninterruptible(void)
2670{
2671 unsigned long i, sum = 0;
2672
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08002673 for_each_possible_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002674 sum += cpu_rq(i)->nr_uninterruptible;
2675
2676 /*
2677 * Since we read the counters lockless, it might be slightly
2678 * inaccurate. Do not allow it to go below zero though:
2679 */
2680 if (unlikely((long)sum < 0))
2681 sum = 0;
2682
2683 return sum;
2684}
2685
2686unsigned long long nr_context_switches(void)
2687{
Steven Rostedtcc94abf2006-06-27 02:54:31 -07002688 int i;
2689 unsigned long long sum = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002690
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08002691 for_each_possible_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002692 sum += cpu_rq(i)->nr_switches;
2693
2694 return sum;
2695}
2696
2697unsigned long nr_iowait(void)
2698{
2699 unsigned long i, sum = 0;
2700
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08002701 for_each_possible_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002702 sum += atomic_read(&cpu_rq(i)->nr_iowait);
2703
2704 return sum;
2705}
2706
Jack Steinerdb1b1fe2006-03-31 02:31:21 -08002707unsigned long nr_active(void)
2708{
2709 unsigned long i, running = 0, uninterruptible = 0;
2710
2711 for_each_online_cpu(i) {
2712 running += cpu_rq(i)->nr_running;
2713 uninterruptible += cpu_rq(i)->nr_uninterruptible;
2714 }
2715
2716 if (unlikely((long)uninterruptible < 0))
2717 uninterruptible = 0;
2718
2719 return running + uninterruptible;
2720}
2721
Linus Torvalds1da177e2005-04-16 15:20:36 -07002722/*
Ingo Molnardd41f592007-07-09 18:51:59 +02002723 * Update rq->cpu_load[] statistics. This function is usually called every
2724 * scheduler tick (TICK_NSEC).
Ingo Molnar48f24c42006-07-03 00:25:40 -07002725 */
Ingo Molnardd41f592007-07-09 18:51:59 +02002726static void update_cpu_load(struct rq *this_rq)
Ingo Molnar48f24c42006-07-03 00:25:40 -07002727{
Dmitry Adamushko495eca42007-10-15 17:00:06 +02002728 unsigned long this_load = this_rq->load.weight;
Ingo Molnardd41f592007-07-09 18:51:59 +02002729 int i, scale;
2730
2731 this_rq->nr_load_updates++;
Ingo Molnardd41f592007-07-09 18:51:59 +02002732
2733 /* Update our load: */
2734 for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
2735 unsigned long old_load, new_load;
2736
2737 /* scale is effectively 1 << i now, and >> i divides by scale */
2738
2739 old_load = this_rq->cpu_load[i];
2740 new_load = this_load;
Ingo Molnara25707f2007-10-15 17:00:03 +02002741 /*
2742 * Round up the averaging division if load is increasing. This
2743 * prevents us from getting stuck on 9 if the load is 10, for
2744 * example.
2745 */
2746 if (new_load > old_load)
2747 new_load += scale-1;
Ingo Molnardd41f592007-07-09 18:51:59 +02002748 this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
2749 }
Ingo Molnar48f24c42006-07-03 00:25:40 -07002750}
2751
Ingo Molnardd41f592007-07-09 18:51:59 +02002752#ifdef CONFIG_SMP
2753
Ingo Molnar48f24c42006-07-03 00:25:40 -07002754/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002755 * double_rq_lock - safely lock two runqueues
2756 *
2757 * Note this does not disable interrupts like task_rq_lock,
2758 * you need to do so manually before calling.
2759 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07002760static void double_rq_lock(struct rq *rq1, struct rq *rq2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002761 __acquires(rq1->lock)
2762 __acquires(rq2->lock)
2763{
Kirill Korotaev054b9102006-12-10 02:20:11 -08002764 BUG_ON(!irqs_disabled());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002765 if (rq1 == rq2) {
2766 spin_lock(&rq1->lock);
2767 __acquire(rq2->lock); /* Fake it out ;) */
2768 } else {
Chen, Kenneth Wc96d1452006-06-27 02:54:28 -07002769 if (rq1 < rq2) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002770 spin_lock(&rq1->lock);
2771 spin_lock(&rq2->lock);
2772 } else {
2773 spin_lock(&rq2->lock);
2774 spin_lock(&rq1->lock);
2775 }
2776 }
Ingo Molnar6e82a3b2007-08-09 11:16:51 +02002777 update_rq_clock(rq1);
2778 update_rq_clock(rq2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002779}
2780
2781/*
2782 * double_rq_unlock - safely unlock two runqueues
2783 *
2784 * Note this does not restore interrupts like task_rq_unlock,
2785 * you need to do so manually after calling.
2786 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07002787static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002788 __releases(rq1->lock)
2789 __releases(rq2->lock)
2790{
2791 spin_unlock(&rq1->lock);
2792 if (rq1 != rq2)
2793 spin_unlock(&rq2->lock);
2794 else
2795 __release(rq2->lock);
2796}
2797
2798/*
2799 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
2800 */
Steven Rostedte8fa1362008-01-25 21:08:05 +01002801static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002802 __releases(this_rq->lock)
2803 __acquires(busiest->lock)
2804 __acquires(this_rq->lock)
2805{
Steven Rostedte8fa1362008-01-25 21:08:05 +01002806 int ret = 0;
2807
Kirill Korotaev054b9102006-12-10 02:20:11 -08002808 if (unlikely(!irqs_disabled())) {
2809 /* printk() doesn't work good under rq->lock */
2810 spin_unlock(&this_rq->lock);
2811 BUG_ON(1);
2812 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002813 if (unlikely(!spin_trylock(&busiest->lock))) {
Chen, Kenneth Wc96d1452006-06-27 02:54:28 -07002814 if (busiest < this_rq) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002815 spin_unlock(&this_rq->lock);
2816 spin_lock(&busiest->lock);
2817 spin_lock(&this_rq->lock);
Steven Rostedte8fa1362008-01-25 21:08:05 +01002818 ret = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002819 } else
2820 spin_lock(&busiest->lock);
2821 }
Steven Rostedte8fa1362008-01-25 21:08:05 +01002822 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002823}
2824
2825/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002826 * If dest_cpu is allowed for this process, migrate the task to it.
2827 * This is accomplished by forcing the cpu_allowed mask to only
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01002828 * allow dest_cpu, which will force the cpu onto dest_cpu. Then
Linus Torvalds1da177e2005-04-16 15:20:36 -07002829 * the cpu_allowed mask is restored.
2830 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07002831static void sched_migrate_task(struct task_struct *p, int dest_cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002832{
Ingo Molnar70b97a72006-07-03 00:25:42 -07002833 struct migration_req req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002834 unsigned long flags;
Ingo Molnar70b97a72006-07-03 00:25:42 -07002835 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002836
2837 rq = task_rq_lock(p, &flags);
2838 if (!cpu_isset(dest_cpu, p->cpus_allowed)
2839 || unlikely(cpu_is_offline(dest_cpu)))
2840 goto out;
2841
2842 /* force the process onto the specified CPU */
2843 if (migrate_task(p, dest_cpu, &req)) {
2844 /* Need to wait for migration thread (might exit: take ref). */
2845 struct task_struct *mt = rq->migration_thread;
Ingo Molnar36c8b582006-07-03 00:25:41 -07002846
Linus Torvalds1da177e2005-04-16 15:20:36 -07002847 get_task_struct(mt);
2848 task_rq_unlock(rq, &flags);
2849 wake_up_process(mt);
2850 put_task_struct(mt);
2851 wait_for_completion(&req.done);
Ingo Molnar36c8b582006-07-03 00:25:41 -07002852
Linus Torvalds1da177e2005-04-16 15:20:36 -07002853 return;
2854 }
2855out:
2856 task_rq_unlock(rq, &flags);
2857}
2858
2859/*
Nick Piggin476d1392005-06-25 14:57:29 -07002860 * sched_exec - execve() is a valuable balancing opportunity, because at
2861 * this point the task has the smallest effective memory and cache footprint.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002862 */
2863void sched_exec(void)
2864{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002865 int new_cpu, this_cpu = get_cpu();
Nick Piggin476d1392005-06-25 14:57:29 -07002866 new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002867 put_cpu();
Nick Piggin476d1392005-06-25 14:57:29 -07002868 if (new_cpu != this_cpu)
2869 sched_migrate_task(current, new_cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002870}
2871
2872/*
2873 * pull_task - move a task from a remote runqueue to the local runqueue.
2874 * Both runqueues must be locked.
2875 */
Ingo Molnardd41f592007-07-09 18:51:59 +02002876static void pull_task(struct rq *src_rq, struct task_struct *p,
2877 struct rq *this_rq, int this_cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002878{
Ingo Molnar2e1cb742007-08-09 11:16:49 +02002879 deactivate_task(src_rq, p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002880 set_task_cpu(p, this_cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02002881 activate_task(this_rq, p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002882 /*
2883 * Note that idle threads have a prio of MAX_PRIO, for this test
2884 * to be always true for them.
2885 */
Ingo Molnardd41f592007-07-09 18:51:59 +02002886 check_preempt_curr(this_rq, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002887}
2888
2889/*
2890 * can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
2891 */
Arjan van de Ven858119e2006-01-14 13:20:43 -08002892static
Ingo Molnar70b97a72006-07-03 00:25:42 -07002893int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
Ingo Molnard15bcfd2007-07-09 18:51:57 +02002894 struct sched_domain *sd, enum cpu_idle_type idle,
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07002895 int *all_pinned)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002896{
2897 /*
2898 * We do not migrate tasks that are:
2899 * 1) running (obviously), or
2900 * 2) cannot be migrated to this CPU due to cpus_allowed, or
2901 * 3) are cache-hot on their current CPU.
2902 */
Ingo Molnarcc367732007-10-15 17:00:18 +02002903 if (!cpu_isset(this_cpu, p->cpus_allowed)) {
2904 schedstat_inc(p, se.nr_failed_migrations_affine);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002905 return 0;
Ingo Molnarcc367732007-10-15 17:00:18 +02002906 }
Nick Piggin81026792005-06-25 14:57:07 -07002907 *all_pinned = 0;
2908
Ingo Molnarcc367732007-10-15 17:00:18 +02002909 if (task_running(rq, p)) {
2910 schedstat_inc(p, se.nr_failed_migrations_running);
Nick Piggin81026792005-06-25 14:57:07 -07002911 return 0;
Ingo Molnarcc367732007-10-15 17:00:18 +02002912 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002913
Ingo Molnarda84d962007-10-15 17:00:18 +02002914 /*
2915 * Aggressive migration if:
2916 * 1) task is cache cold, or
2917 * 2) too many balance attempts have failed.
2918 */
2919
Ingo Molnar6bc16652007-10-15 17:00:18 +02002920 if (!task_hot(p, rq->clock, sd) ||
2921 sd->nr_balance_failed > sd->cache_nice_tries) {
Ingo Molnarda84d962007-10-15 17:00:18 +02002922#ifdef CONFIG_SCHEDSTATS
Ingo Molnarcc367732007-10-15 17:00:18 +02002923 if (task_hot(p, rq->clock, sd)) {
Ingo Molnarda84d962007-10-15 17:00:18 +02002924 schedstat_inc(sd, lb_hot_gained[idle]);
Ingo Molnarcc367732007-10-15 17:00:18 +02002925 schedstat_inc(p, se.nr_forced_migrations);
2926 }
Ingo Molnarda84d962007-10-15 17:00:18 +02002927#endif
2928 return 1;
2929 }
2930
Ingo Molnarcc367732007-10-15 17:00:18 +02002931 if (task_hot(p, rq->clock, sd)) {
2932 schedstat_inc(p, se.nr_failed_migrations_hot);
Ingo Molnarda84d962007-10-15 17:00:18 +02002933 return 0;
Ingo Molnarcc367732007-10-15 17:00:18 +02002934 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002935 return 1;
2936}
2937
Peter Williamse1d14842007-10-24 18:23:51 +02002938static unsigned long
2939balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
2940 unsigned long max_load_move, struct sched_domain *sd,
2941 enum cpu_idle_type idle, int *all_pinned,
2942 int *this_best_prio, struct rq_iterator *iterator)
Ingo Molnardd41f592007-07-09 18:51:59 +02002943{
Peter Zijlstra051c6762008-06-27 13:41:31 +02002944 int loops = 0, pulled = 0, pinned = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02002945 struct task_struct *p;
2946 long rem_load_move = max_load_move;
2947
Peter Williamse1d14842007-10-24 18:23:51 +02002948 if (max_load_move == 0)
Ingo Molnardd41f592007-07-09 18:51:59 +02002949 goto out;
2950
2951 pinned = 1;
2952
2953 /*
2954 * Start the load-balancing iterator:
2955 */
2956 p = iterator->start(iterator->arg);
2957next:
Peter Zijlstrab82d9fd2007-11-09 22:39:39 +01002958 if (!p || loops++ > sysctl_sched_nr_migrate)
Ingo Molnardd41f592007-07-09 18:51:59 +02002959 goto out;
Peter Zijlstra051c6762008-06-27 13:41:31 +02002960
2961 if ((p->se.load.weight >> 1) > rem_load_move ||
Ingo Molnardd41f592007-07-09 18:51:59 +02002962 !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
Ingo Molnardd41f592007-07-09 18:51:59 +02002963 p = iterator->next(iterator->arg);
2964 goto next;
2965 }
2966
2967 pull_task(busiest, p, this_rq, this_cpu);
2968 pulled++;
2969 rem_load_move -= p->se.load.weight;
2970
2971 /*
Peter Zijlstrab82d9fd2007-11-09 22:39:39 +01002972 * We only want to steal up to the prescribed amount of weighted load.
Ingo Molnardd41f592007-07-09 18:51:59 +02002973 */
Peter Williamse1d14842007-10-24 18:23:51 +02002974 if (rem_load_move > 0) {
Peter Williamsa4ac01c2007-08-09 11:16:46 +02002975 if (p->prio < *this_best_prio)
2976 *this_best_prio = p->prio;
Ingo Molnardd41f592007-07-09 18:51:59 +02002977 p = iterator->next(iterator->arg);
2978 goto next;
2979 }
2980out:
2981 /*
Peter Williamse1d14842007-10-24 18:23:51 +02002982 * Right now, this is one of only two places pull_task() is called,
Ingo Molnardd41f592007-07-09 18:51:59 +02002983 * so we can safely collect pull_task() stats here rather than
2984 * inside pull_task().
2985 */
2986 schedstat_add(sd, lb_gained[idle], pulled);
2987
2988 if (all_pinned)
2989 *all_pinned = pinned;
Peter Williamse1d14842007-10-24 18:23:51 +02002990
2991 return max_load_move - rem_load_move;
Ingo Molnardd41f592007-07-09 18:51:59 +02002992}
Ingo Molnar48f24c42006-07-03 00:25:40 -07002993
Linus Torvalds1da177e2005-04-16 15:20:36 -07002994/*
Peter Williams43010652007-08-09 11:16:46 +02002995 * move_tasks tries to move up to max_load_move weighted load from busiest to
2996 * this_rq, as part of a balancing operation within domain "sd".
2997 * Returns 1 if successful and 0 otherwise.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002998 *
2999 * Called with both runqueues locked.
3000 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07003001static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
Peter Williams43010652007-08-09 11:16:46 +02003002 unsigned long max_load_move,
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003003 struct sched_domain *sd, enum cpu_idle_type idle,
Peter Williams2dd73a42006-06-27 02:54:34 -07003004 int *all_pinned)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003005{
Ingo Molnar5522d5d2007-10-15 17:00:12 +02003006 const struct sched_class *class = sched_class_highest;
Peter Williams43010652007-08-09 11:16:46 +02003007 unsigned long total_load_moved = 0;
Peter Williamsa4ac01c2007-08-09 11:16:46 +02003008 int this_best_prio = this_rq->curr->prio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003009
Ingo Molnardd41f592007-07-09 18:51:59 +02003010 do {
Peter Williams43010652007-08-09 11:16:46 +02003011 total_load_moved +=
3012 class->load_balance(this_rq, this_cpu, busiest,
Peter Williamse1d14842007-10-24 18:23:51 +02003013 max_load_move - total_load_moved,
Peter Williamsa4ac01c2007-08-09 11:16:46 +02003014 sd, idle, all_pinned, &this_best_prio);
Ingo Molnardd41f592007-07-09 18:51:59 +02003015 class = class->next;
Gregory Haskinsc4acb2c2008-06-27 14:29:55 -06003016
3017 if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
3018 break;
3019
Peter Williams43010652007-08-09 11:16:46 +02003020 } while (class && max_load_move > total_load_moved);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003021
Peter Williams43010652007-08-09 11:16:46 +02003022 return total_load_moved > 0;
3023}
3024
Peter Williamse1d14842007-10-24 18:23:51 +02003025static int
3026iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
3027 struct sched_domain *sd, enum cpu_idle_type idle,
3028 struct rq_iterator *iterator)
3029{
3030 struct task_struct *p = iterator->start(iterator->arg);
3031 int pinned = 0;
3032
3033 while (p) {
3034 if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
3035 pull_task(busiest, p, this_rq, this_cpu);
3036 /*
3037 * Right now, this is only the second place pull_task()
3038 * is called, so we can safely collect pull_task()
3039 * stats here rather than inside pull_task().
3040 */
3041 schedstat_inc(sd, lb_gained[idle]);
3042
3043 return 1;
3044 }
3045 p = iterator->next(iterator->arg);
3046 }
3047
3048 return 0;
3049}
3050
Peter Williams43010652007-08-09 11:16:46 +02003051/*
3052 * move_one_task tries to move exactly one task from busiest to this_rq, as
3053 * part of active balancing operations within "domain".
3054 * Returns 1 if successful and 0 otherwise.
3055 *
3056 * Called with both runqueues locked.
3057 */
3058static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
3059 struct sched_domain *sd, enum cpu_idle_type idle)
3060{
Ingo Molnar5522d5d2007-10-15 17:00:12 +02003061 const struct sched_class *class;
Peter Williams43010652007-08-09 11:16:46 +02003062
3063 for (class = sched_class_highest; class; class = class->next)
Peter Williamse1d14842007-10-24 18:23:51 +02003064 if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle))
Peter Williams43010652007-08-09 11:16:46 +02003065 return 1;
3066
3067 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003068}
3069
3070/*
3071 * find_busiest_group finds and returns the busiest CPU group within the
Ingo Molnar48f24c42006-07-03 00:25:40 -07003072 * domain. It calculates and returns the amount of weighted load which
3073 * should be moved to restore balance via the imbalance parameter.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003074 */
3075static struct sched_group *
3076find_busiest_group(struct sched_domain *sd, int this_cpu,
Ingo Molnardd41f592007-07-09 18:51:59 +02003077 unsigned long *imbalance, enum cpu_idle_type idle,
Mike Travis7c16ec52008-04-04 18:11:11 -07003078 int *sd_idle, const cpumask_t *cpus, int *balance)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003079{
3080 struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups;
3081 unsigned long max_load, avg_load, total_load, this_load, total_pwr;
Siddha, Suresh B0c117f12005-09-10 00:26:21 -07003082 unsigned long max_pull;
Peter Williams2dd73a42006-06-27 02:54:34 -07003083 unsigned long busiest_load_per_task, busiest_nr_running;
3084 unsigned long this_load_per_task, this_nr_running;
Ken Chen908a7c12007-10-17 16:55:11 +02003085 int load_idx, group_imb = 0;
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003086#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
3087 int power_savings_balance = 1;
3088 unsigned long leader_nr_running = 0, min_load_per_task = 0;
3089 unsigned long min_nr_running = ULONG_MAX;
3090 struct sched_group *group_min = NULL, *group_leader = NULL;
3091#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07003092
3093 max_load = this_load = total_load = total_pwr = 0;
Peter Williams2dd73a42006-06-27 02:54:34 -07003094 busiest_load_per_task = busiest_nr_running = 0;
3095 this_load_per_task = this_nr_running = 0;
Peter Zijlstra408ed062008-06-27 13:41:28 +02003096
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003097 if (idle == CPU_NOT_IDLE)
Nick Piggin78979862005-06-25 14:57:13 -07003098 load_idx = sd->busy_idx;
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003099 else if (idle == CPU_NEWLY_IDLE)
Nick Piggin78979862005-06-25 14:57:13 -07003100 load_idx = sd->newidle_idx;
3101 else
3102 load_idx = sd->idle_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003103
3104 do {
Ken Chen908a7c12007-10-17 16:55:11 +02003105 unsigned long load, group_capacity, max_cpu_load, min_cpu_load;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003106 int local_group;
3107 int i;
Ken Chen908a7c12007-10-17 16:55:11 +02003108 int __group_imb = 0;
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003109 unsigned int balance_cpu = -1, first_idle_cpu = 0;
Peter Williams2dd73a42006-06-27 02:54:34 -07003110 unsigned long sum_nr_running, sum_weighted_load;
Peter Zijlstra408ed062008-06-27 13:41:28 +02003111 unsigned long sum_avg_load_per_task;
3112 unsigned long avg_load_per_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003113
3114 local_group = cpu_isset(this_cpu, group->cpumask);
3115
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003116 if (local_group)
3117 balance_cpu = first_cpu(group->cpumask);
3118
Linus Torvalds1da177e2005-04-16 15:20:36 -07003119 /* Tally up the load of all CPUs in the group */
Peter Williams2dd73a42006-06-27 02:54:34 -07003120 sum_weighted_load = sum_nr_running = avg_load = 0;
Peter Zijlstra408ed062008-06-27 13:41:28 +02003121 sum_avg_load_per_task = avg_load_per_task = 0;
3122
Ken Chen908a7c12007-10-17 16:55:11 +02003123 max_cpu_load = 0;
3124 min_cpu_load = ~0UL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003125
3126 for_each_cpu_mask(i, group->cpumask) {
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003127 struct rq *rq;
3128
3129 if (!cpu_isset(i, *cpus))
3130 continue;
3131
3132 rq = cpu_rq(i);
Peter Williams2dd73a42006-06-27 02:54:34 -07003133
Suresh Siddha9439aab2007-07-19 21:28:35 +02003134 if (*sd_idle && rq->nr_running)
Nick Piggin5969fe02005-09-10 00:26:19 -07003135 *sd_idle = 0;
3136
Linus Torvalds1da177e2005-04-16 15:20:36 -07003137 /* Bias balancing toward cpus of our domain */
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003138 if (local_group) {
3139 if (idle_cpu(i) && !first_idle_cpu) {
3140 first_idle_cpu = 1;
3141 balance_cpu = i;
3142 }
3143
Nick Piggina2000572006-02-10 01:51:02 -08003144 load = target_load(i, load_idx);
Ken Chen908a7c12007-10-17 16:55:11 +02003145 } else {
Nick Piggina2000572006-02-10 01:51:02 -08003146 load = source_load(i, load_idx);
Ken Chen908a7c12007-10-17 16:55:11 +02003147 if (load > max_cpu_load)
3148 max_cpu_load = load;
3149 if (min_cpu_load > load)
3150 min_cpu_load = load;
3151 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003152
3153 avg_load += load;
Peter Williams2dd73a42006-06-27 02:54:34 -07003154 sum_nr_running += rq->nr_running;
Ingo Molnardd41f592007-07-09 18:51:59 +02003155 sum_weighted_load += weighted_cpuload(i);
Peter Zijlstra408ed062008-06-27 13:41:28 +02003156
3157 sum_avg_load_per_task += cpu_avg_load_per_task(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003158 }
3159
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003160 /*
3161 * First idle cpu or the first cpu(busiest) in this sched group
3162 * is eligible for doing load balancing at this and above
Suresh Siddha9439aab2007-07-19 21:28:35 +02003163 * domains. In the newly idle case, we will allow all the cpu's
3164 * to do the newly idle load balance.
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003165 */
Suresh Siddha9439aab2007-07-19 21:28:35 +02003166 if (idle != CPU_NEWLY_IDLE && local_group &&
3167 balance_cpu != this_cpu && balance) {
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003168 *balance = 0;
3169 goto ret;
3170 }
3171
Linus Torvalds1da177e2005-04-16 15:20:36 -07003172 total_load += avg_load;
Eric Dumazet5517d862007-05-08 00:32:57 -07003173 total_pwr += group->__cpu_power;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003174
3175 /* Adjust by relative CPU power of the group */
Eric Dumazet5517d862007-05-08 00:32:57 -07003176 avg_load = sg_div_cpu_power(group,
3177 avg_load * SCHED_LOAD_SCALE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003178
Peter Zijlstra408ed062008-06-27 13:41:28 +02003179
3180 /*
3181 * Consider the group unbalanced when the imbalance is larger
3182 * than the average weight of two tasks.
3183 *
3184 * APZ: with cgroup the avg task weight can vary wildly and
3185 * might not be a suitable number - should we keep a
3186 * normalized nr_running number somewhere that negates
3187 * the hierarchy?
3188 */
3189 avg_load_per_task = sg_div_cpu_power(group,
3190 sum_avg_load_per_task * SCHED_LOAD_SCALE);
3191
3192 if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
Ken Chen908a7c12007-10-17 16:55:11 +02003193 __group_imb = 1;
3194
Eric Dumazet5517d862007-05-08 00:32:57 -07003195 group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003196
Linus Torvalds1da177e2005-04-16 15:20:36 -07003197 if (local_group) {
3198 this_load = avg_load;
3199 this = group;
Peter Williams2dd73a42006-06-27 02:54:34 -07003200 this_nr_running = sum_nr_running;
3201 this_load_per_task = sum_weighted_load;
3202 } else if (avg_load > max_load &&
Ken Chen908a7c12007-10-17 16:55:11 +02003203 (sum_nr_running > group_capacity || __group_imb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003204 max_load = avg_load;
3205 busiest = group;
Peter Williams2dd73a42006-06-27 02:54:34 -07003206 busiest_nr_running = sum_nr_running;
3207 busiest_load_per_task = sum_weighted_load;
Ken Chen908a7c12007-10-17 16:55:11 +02003208 group_imb = __group_imb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003209 }
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003210
3211#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
3212 /*
3213 * Busy processors will not participate in power savings
3214 * balance.
3215 */
Ingo Molnardd41f592007-07-09 18:51:59 +02003216 if (idle == CPU_NOT_IDLE ||
3217 !(sd->flags & SD_POWERSAVINGS_BALANCE))
3218 goto group_next;
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003219
3220 /*
3221 * If the local group is idle or completely loaded
3222 * no need to do power savings balance at this domain
3223 */
3224 if (local_group && (this_nr_running >= group_capacity ||
3225 !this_nr_running))
3226 power_savings_balance = 0;
3227
Ingo Molnardd41f592007-07-09 18:51:59 +02003228 /*
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003229 * If a group is already running at full capacity or idle,
3230 * don't include that group in power savings calculations
Ingo Molnardd41f592007-07-09 18:51:59 +02003231 */
3232 if (!power_savings_balance || sum_nr_running >= group_capacity
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003233 || !sum_nr_running)
Ingo Molnardd41f592007-07-09 18:51:59 +02003234 goto group_next;
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003235
Ingo Molnardd41f592007-07-09 18:51:59 +02003236 /*
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003237 * Calculate the group which has the least non-idle load.
Ingo Molnardd41f592007-07-09 18:51:59 +02003238 * This is the group from where we need to pick up the load
3239 * for saving power
3240 */
3241 if ((sum_nr_running < min_nr_running) ||
3242 (sum_nr_running == min_nr_running &&
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003243 first_cpu(group->cpumask) <
3244 first_cpu(group_min->cpumask))) {
Ingo Molnardd41f592007-07-09 18:51:59 +02003245 group_min = group;
3246 min_nr_running = sum_nr_running;
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003247 min_load_per_task = sum_weighted_load /
3248 sum_nr_running;
Ingo Molnardd41f592007-07-09 18:51:59 +02003249 }
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003250
Ingo Molnardd41f592007-07-09 18:51:59 +02003251 /*
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003252 * Calculate the group which is almost near its
Ingo Molnardd41f592007-07-09 18:51:59 +02003253 * capacity but still has some space to pick up some load
3254 * from other group and save more power
3255 */
3256 if (sum_nr_running <= group_capacity - 1) {
3257 if (sum_nr_running > leader_nr_running ||
3258 (sum_nr_running == leader_nr_running &&
3259 first_cpu(group->cpumask) >
3260 first_cpu(group_leader->cpumask))) {
3261 group_leader = group;
3262 leader_nr_running = sum_nr_running;
3263 }
Ingo Molnar48f24c42006-07-03 00:25:40 -07003264 }
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003265group_next:
3266#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07003267 group = group->next;
3268 } while (group != sd->groups);
3269
Peter Williams2dd73a42006-06-27 02:54:34 -07003270 if (!busiest || this_load >= max_load || busiest_nr_running == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003271 goto out_balanced;
3272
3273 avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr;
3274
3275 if (this_load >= avg_load ||
3276 100*max_load <= sd->imbalance_pct*this_load)
3277 goto out_balanced;
3278
Peter Williams2dd73a42006-06-27 02:54:34 -07003279 busiest_load_per_task /= busiest_nr_running;
Ken Chen908a7c12007-10-17 16:55:11 +02003280 if (group_imb)
3281 busiest_load_per_task = min(busiest_load_per_task, avg_load);
3282
Linus Torvalds1da177e2005-04-16 15:20:36 -07003283 /*
3284 * We're trying to get all the cpus to the average_load, so we don't
3285 * want to push ourselves above the average load, nor do we wish to
3286 * reduce the max loaded cpu below the average load, as either of these
3287 * actions would just result in more rebalancing later, and ping-pong
3288 * tasks around. Thus we look for the minimum possible imbalance.
3289 * Negative imbalances (*we* are more loaded than anyone else) will
3290 * be counted as no imbalance for these purposes -- we can't fix that
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01003291 * by pulling tasks to us. Be careful of negative numbers as they'll
Linus Torvalds1da177e2005-04-16 15:20:36 -07003292 * appear as very large values with unsigned longs.
3293 */
Peter Williams2dd73a42006-06-27 02:54:34 -07003294 if (max_load <= busiest_load_per_task)
3295 goto out_balanced;
3296
3297 /*
3298 * In the presence of smp nice balancing, certain scenarios can have
3299 * max load less than avg load(as we skip the groups at or below
3300 * its cpu_power, while calculating max_load..)
3301 */
3302 if (max_load < avg_load) {
3303 *imbalance = 0;
3304 goto small_imbalance;
3305 }
Siddha, Suresh B0c117f12005-09-10 00:26:21 -07003306
3307 /* Don't want to pull so many tasks that a group would go idle */
Peter Williams2dd73a42006-06-27 02:54:34 -07003308 max_pull = min(max_load - avg_load, max_load - busiest_load_per_task);
Siddha, Suresh B0c117f12005-09-10 00:26:21 -07003309
Linus Torvalds1da177e2005-04-16 15:20:36 -07003310 /* How much load to actually move to equalise the imbalance */
Eric Dumazet5517d862007-05-08 00:32:57 -07003311 *imbalance = min(max_pull * busiest->__cpu_power,
3312 (avg_load - this_load) * this->__cpu_power)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003313 / SCHED_LOAD_SCALE;
3314
Peter Williams2dd73a42006-06-27 02:54:34 -07003315 /*
3316 * if *imbalance is less than the average load per runnable task
3317 * there is no gaurantee that any tasks will be moved so we'll have
3318 * a think about bumping its value to force at least one task to be
3319 * moved
3320 */
Suresh Siddha7fd0d2d2007-09-05 14:32:48 +02003321 if (*imbalance < busiest_load_per_task) {
Ingo Molnar48f24c42006-07-03 00:25:40 -07003322 unsigned long tmp, pwr_now, pwr_move;
Peter Williams2dd73a42006-06-27 02:54:34 -07003323 unsigned int imbn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003324
Peter Williams2dd73a42006-06-27 02:54:34 -07003325small_imbalance:
3326 pwr_move = pwr_now = 0;
3327 imbn = 2;
3328 if (this_nr_running) {
3329 this_load_per_task /= this_nr_running;
3330 if (busiest_load_per_task > this_load_per_task)
3331 imbn = 1;
3332 } else
Peter Zijlstra408ed062008-06-27 13:41:28 +02003333 this_load_per_task = cpu_avg_load_per_task(this_cpu);
Peter Williams2dd73a42006-06-27 02:54:34 -07003334
Peter Zijlstra408ed062008-06-27 13:41:28 +02003335 if (max_load - this_load + 2*busiest_load_per_task >=
Ingo Molnardd41f592007-07-09 18:51:59 +02003336 busiest_load_per_task * imbn) {
Peter Williams2dd73a42006-06-27 02:54:34 -07003337 *imbalance = busiest_load_per_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003338 return busiest;
3339 }
3340
3341 /*
3342 * OK, we don't have enough imbalance to justify moving tasks,
3343 * however we may be able to increase total CPU power used by
3344 * moving them.
3345 */
3346
Eric Dumazet5517d862007-05-08 00:32:57 -07003347 pwr_now += busiest->__cpu_power *
3348 min(busiest_load_per_task, max_load);
3349 pwr_now += this->__cpu_power *
3350 min(this_load_per_task, this_load);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003351 pwr_now /= SCHED_LOAD_SCALE;
3352
3353 /* Amount of load we'd subtract */
Eric Dumazet5517d862007-05-08 00:32:57 -07003354 tmp = sg_div_cpu_power(busiest,
3355 busiest_load_per_task * SCHED_LOAD_SCALE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003356 if (max_load > tmp)
Eric Dumazet5517d862007-05-08 00:32:57 -07003357 pwr_move += busiest->__cpu_power *
Peter Williams2dd73a42006-06-27 02:54:34 -07003358 min(busiest_load_per_task, max_load - tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003359
3360 /* Amount of load we'd add */
Eric Dumazet5517d862007-05-08 00:32:57 -07003361 if (max_load * busiest->__cpu_power <
Miguel Ojeda Sandonis33859f72006-12-10 02:20:38 -08003362 busiest_load_per_task * SCHED_LOAD_SCALE)
Eric Dumazet5517d862007-05-08 00:32:57 -07003363 tmp = sg_div_cpu_power(this,
3364 max_load * busiest->__cpu_power);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003365 else
Eric Dumazet5517d862007-05-08 00:32:57 -07003366 tmp = sg_div_cpu_power(this,
3367 busiest_load_per_task * SCHED_LOAD_SCALE);
3368 pwr_move += this->__cpu_power *
3369 min(this_load_per_task, this_load + tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003370 pwr_move /= SCHED_LOAD_SCALE;
3371
3372 /* Move if we gain throughput */
Suresh Siddha7fd0d2d2007-09-05 14:32:48 +02003373 if (pwr_move > pwr_now)
3374 *imbalance = busiest_load_per_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003375 }
3376
Linus Torvalds1da177e2005-04-16 15:20:36 -07003377 return busiest;
3378
3379out_balanced:
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003380#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003381 if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE))
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003382 goto ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003383
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003384 if (this == group_leader && group_leader != group_min) {
3385 *imbalance = min_load_per_task;
3386 return group_min;
3387 }
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07003388#endif
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003389ret:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003390 *imbalance = 0;
3391 return NULL;
3392}
3393
3394/*
3395 * find_busiest_queue - find the busiest runqueue among the cpus in group.
3396 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07003397static struct rq *
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003398find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle,
Mike Travis7c16ec52008-04-04 18:11:11 -07003399 unsigned long imbalance, const cpumask_t *cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003400{
Ingo Molnar70b97a72006-07-03 00:25:42 -07003401 struct rq *busiest = NULL, *rq;
Peter Williams2dd73a42006-06-27 02:54:34 -07003402 unsigned long max_load = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003403 int i;
3404
3405 for_each_cpu_mask(i, group->cpumask) {
Ingo Molnardd41f592007-07-09 18:51:59 +02003406 unsigned long wl;
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003407
3408 if (!cpu_isset(i, *cpus))
3409 continue;
3410
Ingo Molnar48f24c42006-07-03 00:25:40 -07003411 rq = cpu_rq(i);
Ingo Molnardd41f592007-07-09 18:51:59 +02003412 wl = weighted_cpuload(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003413
Ingo Molnardd41f592007-07-09 18:51:59 +02003414 if (rq->nr_running == 1 && wl > imbalance)
Peter Williams2dd73a42006-06-27 02:54:34 -07003415 continue;
3416
Ingo Molnardd41f592007-07-09 18:51:59 +02003417 if (wl > max_load) {
3418 max_load = wl;
Ingo Molnar48f24c42006-07-03 00:25:40 -07003419 busiest = rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003420 }
3421 }
3422
3423 return busiest;
3424}
3425
3426/*
Nick Piggin77391d72005-06-25 14:57:30 -07003427 * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but
3428 * so long as it is large enough.
3429 */
3430#define MAX_PINNED_INTERVAL 512
3431
3432/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003433 * Check this_cpu to ensure it is balanced within domain. Attempt to move
3434 * tasks if there is an imbalance.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003435 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07003436static int load_balance(int this_cpu, struct rq *this_rq,
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003437 struct sched_domain *sd, enum cpu_idle_type idle,
Mike Travis7c16ec52008-04-04 18:11:11 -07003438 int *balance, cpumask_t *cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003439{
Peter Williams43010652007-08-09 11:16:46 +02003440 int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003441 struct sched_group *group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003442 unsigned long imbalance;
Ingo Molnar70b97a72006-07-03 00:25:42 -07003443 struct rq *busiest;
Christoph Lameterfe2eea32006-12-10 02:20:21 -08003444 unsigned long flags;
Nick Piggin5969fe02005-09-10 00:26:19 -07003445
Mike Travis7c16ec52008-04-04 18:11:11 -07003446 cpus_setall(*cpus);
3447
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003448 /*
3449 * When power savings policy is enabled for the parent domain, idle
3450 * sibling can pick up load irrespective of busy siblings. In this case,
Ingo Molnardd41f592007-07-09 18:51:59 +02003451 * let the state of idle sibling percolate up as CPU_IDLE, instead of
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003452 * portraying it as CPU_NOT_IDLE.
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003453 */
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003454 if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER &&
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003455 !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
Nick Piggin5969fe02005-09-10 00:26:19 -07003456 sd_idle = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003457
Ingo Molnar2d723762007-10-15 17:00:12 +02003458 schedstat_inc(sd, lb_count[idle]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003459
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003460redo:
Peter Zijlstrac8cba852008-06-27 13:41:23 +02003461 update_shares(sd);
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003462 group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle,
Mike Travis7c16ec52008-04-04 18:11:11 -07003463 cpus, balance);
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003464
Chen, Kenneth W06066712006-12-10 02:20:35 -08003465 if (*balance == 0)
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003466 goto out_balanced;
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003467
Linus Torvalds1da177e2005-04-16 15:20:36 -07003468 if (!group) {
3469 schedstat_inc(sd, lb_nobusyg[idle]);
3470 goto out_balanced;
3471 }
3472
Mike Travis7c16ec52008-04-04 18:11:11 -07003473 busiest = find_busiest_queue(group, idle, imbalance, cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003474 if (!busiest) {
3475 schedstat_inc(sd, lb_nobusyq[idle]);
3476 goto out_balanced;
3477 }
3478
Nick Piggindb935db2005-06-25 14:57:11 -07003479 BUG_ON(busiest == this_rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003480
3481 schedstat_add(sd, lb_imbalance[idle], imbalance);
3482
Peter Williams43010652007-08-09 11:16:46 +02003483 ld_moved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003484 if (busiest->nr_running > 1) {
3485 /*
3486 * Attempt to move tasks. If find_busiest_group has found
3487 * an imbalance but busiest->nr_running <= 1, the group is
Peter Williams43010652007-08-09 11:16:46 +02003488 * still unbalanced. ld_moved simply stays zero, so it is
Linus Torvalds1da177e2005-04-16 15:20:36 -07003489 * correctly treated as an imbalance.
3490 */
Christoph Lameterfe2eea32006-12-10 02:20:21 -08003491 local_irq_save(flags);
Nick Piggine17224b2005-09-10 00:26:18 -07003492 double_rq_lock(this_rq, busiest);
Peter Williams43010652007-08-09 11:16:46 +02003493 ld_moved = move_tasks(this_rq, this_cpu, busiest,
Ingo Molnar48f24c42006-07-03 00:25:40 -07003494 imbalance, sd, idle, &all_pinned);
Nick Piggine17224b2005-09-10 00:26:18 -07003495 double_rq_unlock(this_rq, busiest);
Christoph Lameterfe2eea32006-12-10 02:20:21 -08003496 local_irq_restore(flags);
Nick Piggin81026792005-06-25 14:57:07 -07003497
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003498 /*
3499 * some other cpu did the load balance for us.
3500 */
Peter Williams43010652007-08-09 11:16:46 +02003501 if (ld_moved && this_cpu != smp_processor_id())
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003502 resched_cpu(this_cpu);
3503
Nick Piggin81026792005-06-25 14:57:07 -07003504 /* All tasks on this runqueue were pinned by CPU affinity */
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003505 if (unlikely(all_pinned)) {
Mike Travis7c16ec52008-04-04 18:11:11 -07003506 cpu_clear(cpu_of(busiest), *cpus);
3507 if (!cpus_empty(*cpus))
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003508 goto redo;
Nick Piggin81026792005-06-25 14:57:07 -07003509 goto out_balanced;
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003510 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003511 }
Nick Piggin81026792005-06-25 14:57:07 -07003512
Peter Williams43010652007-08-09 11:16:46 +02003513 if (!ld_moved) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003514 schedstat_inc(sd, lb_failed[idle]);
3515 sd->nr_balance_failed++;
3516
3517 if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003518
Christoph Lameterfe2eea32006-12-10 02:20:21 -08003519 spin_lock_irqsave(&busiest->lock, flags);
Siddha, Suresh Bfa3b6dd2005-09-10 00:26:21 -07003520
3521 /* don't kick the migration_thread, if the curr
3522 * task on busiest cpu can't be moved to this_cpu
3523 */
3524 if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) {
Christoph Lameterfe2eea32006-12-10 02:20:21 -08003525 spin_unlock_irqrestore(&busiest->lock, flags);
Siddha, Suresh Bfa3b6dd2005-09-10 00:26:21 -07003526 all_pinned = 1;
3527 goto out_one_pinned;
3528 }
3529
Linus Torvalds1da177e2005-04-16 15:20:36 -07003530 if (!busiest->active_balance) {
3531 busiest->active_balance = 1;
3532 busiest->push_cpu = this_cpu;
Nick Piggin81026792005-06-25 14:57:07 -07003533 active_balance = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003534 }
Christoph Lameterfe2eea32006-12-10 02:20:21 -08003535 spin_unlock_irqrestore(&busiest->lock, flags);
Nick Piggin81026792005-06-25 14:57:07 -07003536 if (active_balance)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003537 wake_up_process(busiest->migration_thread);
3538
3539 /*
3540 * We've kicked active balancing, reset the failure
3541 * counter.
3542 */
Nick Piggin39507452005-06-25 14:57:09 -07003543 sd->nr_balance_failed = sd->cache_nice_tries+1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003544 }
Nick Piggin81026792005-06-25 14:57:07 -07003545 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07003546 sd->nr_balance_failed = 0;
3547
Nick Piggin81026792005-06-25 14:57:07 -07003548 if (likely(!active_balance)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003549 /* We were unbalanced, so reset the balancing interval */
3550 sd->balance_interval = sd->min_interval;
Nick Piggin81026792005-06-25 14:57:07 -07003551 } else {
3552 /*
3553 * If we've begun active balancing, start to back off. This
3554 * case may not be covered by the all_pinned logic if there
3555 * is only 1 task on the busy runqueue (because we don't call
3556 * move_tasks).
3557 */
3558 if (sd->balance_interval < sd->max_interval)
3559 sd->balance_interval *= 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003560 }
3561
Peter Williams43010652007-08-09 11:16:46 +02003562 if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003563 !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
Peter Zijlstrac09595f2008-06-27 13:41:14 +02003564 ld_moved = -1;
3565
3566 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003567
3568out_balanced:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003569 schedstat_inc(sd, lb_balanced[idle]);
3570
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003571 sd->nr_balance_failed = 0;
Siddha, Suresh Bfa3b6dd2005-09-10 00:26:21 -07003572
3573out_one_pinned:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003574 /* tune up the balancing interval */
Nick Piggin77391d72005-06-25 14:57:30 -07003575 if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) ||
3576 (sd->balance_interval < sd->max_interval))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003577 sd->balance_interval *= 2;
3578
Ingo Molnar48f24c42006-07-03 00:25:40 -07003579 if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003580 !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
Peter Zijlstrac09595f2008-06-27 13:41:14 +02003581 ld_moved = -1;
3582 else
3583 ld_moved = 0;
3584out:
Peter Zijlstrac8cba852008-06-27 13:41:23 +02003585 if (ld_moved)
3586 update_shares(sd);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02003587 return ld_moved;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003588}
3589
3590/*
3591 * Check this_cpu to ensure it is balanced within domain. Attempt to move
3592 * tasks if there is an imbalance.
3593 *
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003594 * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE).
Linus Torvalds1da177e2005-04-16 15:20:36 -07003595 * this_rq is locked.
3596 */
Ingo Molnar48f24c42006-07-03 00:25:40 -07003597static int
Mike Travis7c16ec52008-04-04 18:11:11 -07003598load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd,
3599 cpumask_t *cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003600{
3601 struct sched_group *group;
Ingo Molnar70b97a72006-07-03 00:25:42 -07003602 struct rq *busiest = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003603 unsigned long imbalance;
Peter Williams43010652007-08-09 11:16:46 +02003604 int ld_moved = 0;
Nick Piggin5969fe02005-09-10 00:26:19 -07003605 int sd_idle = 0;
Suresh Siddha969bb4e2007-07-19 21:28:35 +02003606 int all_pinned = 0;
Mike Travis7c16ec52008-04-04 18:11:11 -07003607
3608 cpus_setall(*cpus);
Nick Piggin5969fe02005-09-10 00:26:19 -07003609
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003610 /*
3611 * When power savings policy is enabled for the parent domain, idle
3612 * sibling can pick up load irrespective of busy siblings. In this case,
3613 * let the state of idle sibling percolate up as IDLE, instead of
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003614 * portraying it as CPU_NOT_IDLE.
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003615 */
3616 if (sd->flags & SD_SHARE_CPUPOWER &&
3617 !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
Nick Piggin5969fe02005-09-10 00:26:19 -07003618 sd_idle = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003619
Ingo Molnar2d723762007-10-15 17:00:12 +02003620 schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]);
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003621redo:
Peter Zijlstra3e5459b2008-06-27 13:41:24 +02003622 update_shares_locked(this_rq, sd);
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003623 group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE,
Mike Travis7c16ec52008-04-04 18:11:11 -07003624 &sd_idle, cpus, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003625 if (!group) {
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003626 schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]);
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003627 goto out_balanced;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003628 }
3629
Mike Travis7c16ec52008-04-04 18:11:11 -07003630 busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus);
Nick Piggindb935db2005-06-25 14:57:11 -07003631 if (!busiest) {
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003632 schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]);
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003633 goto out_balanced;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003634 }
3635
Nick Piggindb935db2005-06-25 14:57:11 -07003636 BUG_ON(busiest == this_rq);
3637
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003638 schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance);
Nick Piggind6d5cfa2005-09-10 00:26:16 -07003639
Peter Williams43010652007-08-09 11:16:46 +02003640 ld_moved = 0;
Nick Piggind6d5cfa2005-09-10 00:26:16 -07003641 if (busiest->nr_running > 1) {
3642 /* Attempt to move tasks */
3643 double_lock_balance(this_rq, busiest);
Ingo Molnar6e82a3b2007-08-09 11:16:51 +02003644 /* this_rq->clock is already updated */
3645 update_rq_clock(busiest);
Peter Williams43010652007-08-09 11:16:46 +02003646 ld_moved = move_tasks(this_rq, this_cpu, busiest,
Suresh Siddha969bb4e2007-07-19 21:28:35 +02003647 imbalance, sd, CPU_NEWLY_IDLE,
3648 &all_pinned);
Nick Piggind6d5cfa2005-09-10 00:26:16 -07003649 spin_unlock(&busiest->lock);
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003650
Suresh Siddha969bb4e2007-07-19 21:28:35 +02003651 if (unlikely(all_pinned)) {
Mike Travis7c16ec52008-04-04 18:11:11 -07003652 cpu_clear(cpu_of(busiest), *cpus);
3653 if (!cpus_empty(*cpus))
Christoph Lameter0a2966b2006-09-25 23:30:51 -07003654 goto redo;
3655 }
Nick Piggind6d5cfa2005-09-10 00:26:16 -07003656 }
3657
Peter Williams43010652007-08-09 11:16:46 +02003658 if (!ld_moved) {
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003659 schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]);
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003660 if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
3661 !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
Nick Piggin5969fe02005-09-10 00:26:19 -07003662 return -1;
3663 } else
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003664 sd->nr_balance_failed = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003665
Peter Zijlstra3e5459b2008-06-27 13:41:24 +02003666 update_shares_locked(this_rq, sd);
Peter Williams43010652007-08-09 11:16:46 +02003667 return ld_moved;
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003668
3669out_balanced:
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003670 schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]);
Ingo Molnar48f24c42006-07-03 00:25:40 -07003671 if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
Siddha, Suresh B89c47102006-10-03 01:14:09 -07003672 !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
Nick Piggin5969fe02005-09-10 00:26:19 -07003673 return -1;
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003674 sd->nr_balance_failed = 0;
Ingo Molnar48f24c42006-07-03 00:25:40 -07003675
Nick Piggin16cfb1c2005-06-25 14:57:08 -07003676 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003677}
3678
3679/*
3680 * idle_balance is called by schedule() if this_cpu is about to become
3681 * idle. Attempts to pull tasks from other CPUs.
3682 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07003683static void idle_balance(int this_cpu, struct rq *this_rq)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003684{
3685 struct sched_domain *sd;
Ingo Molnardd41f592007-07-09 18:51:59 +02003686 int pulled_task = -1;
3687 unsigned long next_balance = jiffies + HZ;
Mike Travis7c16ec52008-04-04 18:11:11 -07003688 cpumask_t tmpmask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003689
3690 for_each_domain(this_cpu, sd) {
Christoph Lameter92c4ca52007-06-23 17:16:33 -07003691 unsigned long interval;
3692
3693 if (!(sd->flags & SD_LOAD_BALANCE))
3694 continue;
3695
3696 if (sd->flags & SD_BALANCE_NEWIDLE)
Ingo Molnar48f24c42006-07-03 00:25:40 -07003697 /* If we've pulled tasks over stop searching: */
Mike Travis7c16ec52008-04-04 18:11:11 -07003698 pulled_task = load_balance_newidle(this_cpu, this_rq,
3699 sd, &tmpmask);
Christoph Lameter92c4ca52007-06-23 17:16:33 -07003700
3701 interval = msecs_to_jiffies(sd->balance_interval);
3702 if (time_after(next_balance, sd->last_balance + interval))
3703 next_balance = sd->last_balance + interval;
3704 if (pulled_task)
3705 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003706 }
Ingo Molnardd41f592007-07-09 18:51:59 +02003707 if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
Christoph Lameter1bd77f22006-12-10 02:20:27 -08003708 /*
3709 * We are going idle. next_balance may be set based on
3710 * a busy processor. So reset next_balance.
3711 */
3712 this_rq->next_balance = next_balance;
Ingo Molnardd41f592007-07-09 18:51:59 +02003713 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003714}
3715
3716/*
3717 * active_load_balance is run by migration threads. It pushes running tasks
3718 * off the busiest CPU onto idle CPUs. It requires at least 1 task to be
3719 * running on each physical CPU where possible, and avoids physical /
3720 * logical imbalances.
3721 *
3722 * Called with busiest_rq locked.
3723 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07003724static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003725{
Nick Piggin39507452005-06-25 14:57:09 -07003726 int target_cpu = busiest_rq->push_cpu;
Ingo Molnar70b97a72006-07-03 00:25:42 -07003727 struct sched_domain *sd;
3728 struct rq *target_rq;
Nick Piggin39507452005-06-25 14:57:09 -07003729
Ingo Molnar48f24c42006-07-03 00:25:40 -07003730 /* Is there any task to move? */
Nick Piggin39507452005-06-25 14:57:09 -07003731 if (busiest_rq->nr_running <= 1)
Nick Piggin39507452005-06-25 14:57:09 -07003732 return;
3733
3734 target_rq = cpu_rq(target_cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003735
3736 /*
Nick Piggin39507452005-06-25 14:57:09 -07003737 * This condition is "impossible", if it occurs
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01003738 * we need to fix it. Originally reported by
Nick Piggin39507452005-06-25 14:57:09 -07003739 * Bjorn Helgaas on a 128-cpu setup.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003740 */
Nick Piggin39507452005-06-25 14:57:09 -07003741 BUG_ON(busiest_rq == target_rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003742
Nick Piggin39507452005-06-25 14:57:09 -07003743 /* move a task from busiest_rq to target_rq */
3744 double_lock_balance(busiest_rq, target_rq);
Ingo Molnar6e82a3b2007-08-09 11:16:51 +02003745 update_rq_clock(busiest_rq);
3746 update_rq_clock(target_rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003747
Nick Piggin39507452005-06-25 14:57:09 -07003748 /* Search for an sd spanning us and the target CPU. */
Chen, Kenneth Wc96d1452006-06-27 02:54:28 -07003749 for_each_domain(target_cpu, sd) {
Nick Piggin39507452005-06-25 14:57:09 -07003750 if ((sd->flags & SD_LOAD_BALANCE) &&
Ingo Molnar48f24c42006-07-03 00:25:40 -07003751 cpu_isset(busiest_cpu, sd->span))
Nick Piggin39507452005-06-25 14:57:09 -07003752 break;
Chen, Kenneth Wc96d1452006-06-27 02:54:28 -07003753 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003754
Ingo Molnar48f24c42006-07-03 00:25:40 -07003755 if (likely(sd)) {
Ingo Molnar2d723762007-10-15 17:00:12 +02003756 schedstat_inc(sd, alb_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003757
Peter Williams43010652007-08-09 11:16:46 +02003758 if (move_one_task(target_rq, target_cpu, busiest_rq,
3759 sd, CPU_IDLE))
Ingo Molnar48f24c42006-07-03 00:25:40 -07003760 schedstat_inc(sd, alb_pushed);
3761 else
3762 schedstat_inc(sd, alb_failed);
3763 }
Nick Piggin39507452005-06-25 14:57:09 -07003764 spin_unlock(&target_rq->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003765}
3766
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003767#ifdef CONFIG_NO_HZ
3768static struct {
3769 atomic_t load_balancer;
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01003770 cpumask_t cpu_mask;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003771} nohz ____cacheline_aligned = {
3772 .load_balancer = ATOMIC_INIT(-1),
3773 .cpu_mask = CPU_MASK_NONE,
3774};
3775
Christoph Lameter7835b982006-12-10 02:20:22 -08003776/*
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003777 * This routine will try to nominate the ilb (idle load balancing)
3778 * owner among the cpus whose ticks are stopped. ilb owner will do the idle
3779 * load balancing on behalf of all those cpus. If all the cpus in the system
3780 * go into this tickless mode, then there will be no ilb owner (as there is
3781 * no need for one) and all the cpus will sleep till the next wakeup event
3782 * arrives...
Christoph Lameter7835b982006-12-10 02:20:22 -08003783 *
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003784 * For the ilb owner, tick is not stopped. And this tick will be used
3785 * for idle load balancing. ilb owner will still be part of
3786 * nohz.cpu_mask..
3787 *
3788 * While stopping the tick, this cpu will become the ilb owner if there
3789 * is no other owner. And will be the owner till that cpu becomes busy
3790 * or if all cpus in the system stop their ticks at which point
3791 * there is no need for ilb owner.
3792 *
3793 * When the ilb owner becomes busy, it nominates another owner, during the
3794 * next busy scheduler_tick()
3795 */
3796int select_nohz_load_balancer(int stop_tick)
3797{
3798 int cpu = smp_processor_id();
3799
3800 if (stop_tick) {
3801 cpu_set(cpu, nohz.cpu_mask);
3802 cpu_rq(cpu)->in_nohz_recently = 1;
3803
3804 /*
3805 * If we are going offline and still the leader, give up!
3806 */
3807 if (cpu_is_offline(cpu) &&
3808 atomic_read(&nohz.load_balancer) == cpu) {
3809 if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
3810 BUG();
3811 return 0;
3812 }
3813
3814 /* time for ilb owner also to sleep */
3815 if (cpus_weight(nohz.cpu_mask) == num_online_cpus()) {
3816 if (atomic_read(&nohz.load_balancer) == cpu)
3817 atomic_set(&nohz.load_balancer, -1);
3818 return 0;
3819 }
3820
3821 if (atomic_read(&nohz.load_balancer) == -1) {
3822 /* make me the ilb owner */
3823 if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
3824 return 1;
3825 } else if (atomic_read(&nohz.load_balancer) == cpu)
3826 return 1;
3827 } else {
3828 if (!cpu_isset(cpu, nohz.cpu_mask))
3829 return 0;
3830
3831 cpu_clear(cpu, nohz.cpu_mask);
3832
3833 if (atomic_read(&nohz.load_balancer) == cpu)
3834 if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
3835 BUG();
3836 }
3837 return 0;
3838}
3839#endif
3840
3841static DEFINE_SPINLOCK(balancing);
3842
3843/*
Christoph Lameter7835b982006-12-10 02:20:22 -08003844 * It checks each scheduling domain to see if it is due to be balanced,
3845 * and initiates a balancing operation if so.
3846 *
3847 * Balancing parameters are set up in arch_init_sched_domains.
3848 */
Alexey Dobriyana9957442007-10-15 17:00:13 +02003849static void rebalance_domains(int cpu, enum cpu_idle_type idle)
Christoph Lameter7835b982006-12-10 02:20:22 -08003850{
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003851 int balance = 1;
3852 struct rq *rq = cpu_rq(cpu);
Christoph Lameter7835b982006-12-10 02:20:22 -08003853 unsigned long interval;
3854 struct sched_domain *sd;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003855 /* Earliest time when we have to do rebalance again */
Christoph Lameterc9819f42006-12-10 02:20:25 -08003856 unsigned long next_balance = jiffies + 60*HZ;
Suresh Siddhaf549da82007-08-23 15:18:02 +02003857 int update_next_balance = 0;
Dmitry Adamushkod07355f2008-05-12 21:21:15 +02003858 int need_serialize;
Mike Travis7c16ec52008-04-04 18:11:11 -07003859 cpumask_t tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003860
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003861 for_each_domain(cpu, sd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003862 if (!(sd->flags & SD_LOAD_BALANCE))
3863 continue;
3864
3865 interval = sd->balance_interval;
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003866 if (idle != CPU_IDLE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003867 interval *= sd->busy_factor;
3868
3869 /* scale ms to jiffies */
3870 interval = msecs_to_jiffies(interval);
3871 if (unlikely(!interval))
3872 interval = 1;
Ingo Molnardd41f592007-07-09 18:51:59 +02003873 if (interval > HZ*NR_CPUS/10)
3874 interval = HZ*NR_CPUS/10;
3875
Dmitry Adamushkod07355f2008-05-12 21:21:15 +02003876 need_serialize = sd->flags & SD_SERIALIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003877
Dmitry Adamushkod07355f2008-05-12 21:21:15 +02003878 if (need_serialize) {
Christoph Lameter08c183f2006-12-10 02:20:29 -08003879 if (!spin_trylock(&balancing))
3880 goto out;
3881 }
3882
Christoph Lameterc9819f42006-12-10 02:20:25 -08003883 if (time_after_eq(jiffies, sd->last_balance + interval)) {
Mike Travis7c16ec52008-04-04 18:11:11 -07003884 if (load_balance(cpu, rq, sd, idle, &balance, &tmp)) {
Siddha, Suresh Bfa3b6dd2005-09-10 00:26:21 -07003885 /*
3886 * We've pulled tasks over so either we're no
Nick Piggin5969fe02005-09-10 00:26:19 -07003887 * longer idle, or one of our SMT siblings is
3888 * not idle.
3889 */
Ingo Molnard15bcfd2007-07-09 18:51:57 +02003890 idle = CPU_NOT_IDLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003891 }
Christoph Lameter1bd77f22006-12-10 02:20:27 -08003892 sd->last_balance = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003893 }
Dmitry Adamushkod07355f2008-05-12 21:21:15 +02003894 if (need_serialize)
Christoph Lameter08c183f2006-12-10 02:20:29 -08003895 spin_unlock(&balancing);
3896out:
Suresh Siddhaf549da82007-08-23 15:18:02 +02003897 if (time_after(next_balance, sd->last_balance + interval)) {
Christoph Lameterc9819f42006-12-10 02:20:25 -08003898 next_balance = sd->last_balance + interval;
Suresh Siddhaf549da82007-08-23 15:18:02 +02003899 update_next_balance = 1;
3900 }
Siddha, Suresh B783609c2006-12-10 02:20:33 -08003901
3902 /*
3903 * Stop the load balance at this level. There is another
3904 * CPU in our sched group which is doing load balancing more
3905 * actively.
3906 */
3907 if (!balance)
3908 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003909 }
Suresh Siddhaf549da82007-08-23 15:18:02 +02003910
3911 /*
3912 * next_balance will be updated only when there is a need.
3913 * When the cpu is attached to null domain for ex, it will not be
3914 * updated.
3915 */
3916 if (likely(update_next_balance))
3917 rq->next_balance = next_balance;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003918}
3919
3920/*
3921 * run_rebalance_domains is triggered when needed from the scheduler tick.
3922 * In CONFIG_NO_HZ case, the idle load balance owner will do the
3923 * rebalancing for all the cpus for whom scheduler ticks are stopped.
3924 */
3925static void run_rebalance_domains(struct softirq_action *h)
3926{
Ingo Molnardd41f592007-07-09 18:51:59 +02003927 int this_cpu = smp_processor_id();
3928 struct rq *this_rq = cpu_rq(this_cpu);
3929 enum cpu_idle_type idle = this_rq->idle_at_tick ?
3930 CPU_IDLE : CPU_NOT_IDLE;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003931
Ingo Molnardd41f592007-07-09 18:51:59 +02003932 rebalance_domains(this_cpu, idle);
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003933
3934#ifdef CONFIG_NO_HZ
3935 /*
3936 * If this cpu is the owner for idle load balancing, then do the
3937 * balancing on behalf of the other idle cpus whose ticks are
3938 * stopped.
3939 */
Ingo Molnardd41f592007-07-09 18:51:59 +02003940 if (this_rq->idle_at_tick &&
3941 atomic_read(&nohz.load_balancer) == this_cpu) {
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003942 cpumask_t cpus = nohz.cpu_mask;
3943 struct rq *rq;
3944 int balance_cpu;
3945
Ingo Molnardd41f592007-07-09 18:51:59 +02003946 cpu_clear(this_cpu, cpus);
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003947 for_each_cpu_mask(balance_cpu, cpus) {
3948 /*
3949 * If this cpu gets work to do, stop the load balancing
3950 * work being done for other cpus. Next load
3951 * balancing owner will pick it up.
3952 */
3953 if (need_resched())
3954 break;
3955
Oleg Nesterovde0cf892007-08-12 18:08:19 +02003956 rebalance_domains(balance_cpu, CPU_IDLE);
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003957
3958 rq = cpu_rq(balance_cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02003959 if (time_after(this_rq->next_balance, rq->next_balance))
3960 this_rq->next_balance = rq->next_balance;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003961 }
3962 }
3963#endif
3964}
3965
3966/*
3967 * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
3968 *
3969 * In case of CONFIG_NO_HZ, this is the place where we nominate a new
3970 * idle load balancing owner or decide to stop the periodic load balancing,
3971 * if the whole system is idle.
3972 */
Ingo Molnardd41f592007-07-09 18:51:59 +02003973static inline void trigger_load_balance(struct rq *rq, int cpu)
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003974{
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07003975#ifdef CONFIG_NO_HZ
3976 /*
3977 * If we were in the nohz mode recently and busy at the current
3978 * scheduler tick, then check if we need to nominate new idle
3979 * load balancer.
3980 */
3981 if (rq->in_nohz_recently && !rq->idle_at_tick) {
3982 rq->in_nohz_recently = 0;
3983
3984 if (atomic_read(&nohz.load_balancer) == cpu) {
3985 cpu_clear(cpu, nohz.cpu_mask);
3986 atomic_set(&nohz.load_balancer, -1);
3987 }
3988
3989 if (atomic_read(&nohz.load_balancer) == -1) {
3990 /*
3991 * simple selection for now: Nominate the
3992 * first cpu in the nohz list to be the next
3993 * ilb owner.
3994 *
3995 * TBD: Traverse the sched domains and nominate
3996 * the nearest cpu in the nohz.cpu_mask.
3997 */
3998 int ilb = first_cpu(nohz.cpu_mask);
3999
Mike Travis434d53b2008-04-04 18:11:04 -07004000 if (ilb < nr_cpu_ids)
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -07004001 resched_cpu(ilb);
4002 }
4003 }
4004
4005 /*
4006 * If this cpu is idle and doing idle load balancing for all the
4007 * cpus with ticks stopped, is it time for that to stop?
4008 */
4009 if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu &&
4010 cpus_weight(nohz.cpu_mask) == num_online_cpus()) {
4011 resched_cpu(cpu);
4012 return;
4013 }
4014
4015 /*
4016 * If this cpu is idle and the idle load balancing is done by
4017 * someone else, then no need raise the SCHED_SOFTIRQ
4018 */
4019 if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu &&
4020 cpu_isset(cpu, nohz.cpu_mask))
4021 return;
4022#endif
4023 if (time_after_eq(jiffies, rq->next_balance))
4024 raise_softirq(SCHED_SOFTIRQ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004025}
Ingo Molnardd41f592007-07-09 18:51:59 +02004026
4027#else /* CONFIG_SMP */
4028
Linus Torvalds1da177e2005-04-16 15:20:36 -07004029/*
4030 * on UP we do not need to balance between CPUs:
4031 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07004032static inline void idle_balance(int cpu, struct rq *rq)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004033{
4034}
Ingo Molnardd41f592007-07-09 18:51:59 +02004035
Linus Torvalds1da177e2005-04-16 15:20:36 -07004036#endif
4037
Linus Torvalds1da177e2005-04-16 15:20:36 -07004038DEFINE_PER_CPU(struct kernel_stat, kstat);
4039
4040EXPORT_PER_CPU_SYMBOL(kstat);
4041
4042/*
Ingo Molnar41b86e92007-07-09 18:51:58 +02004043 * Return p->sum_exec_runtime plus any more ns on the sched_clock
4044 * that have not yet been banked in case the task is currently running.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004045 */
Ingo Molnar41b86e92007-07-09 18:51:58 +02004046unsigned long long task_sched_runtime(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004047{
Linus Torvalds1da177e2005-04-16 15:20:36 -07004048 unsigned long flags;
Ingo Molnar41b86e92007-07-09 18:51:58 +02004049 u64 ns, delta_exec;
4050 struct rq *rq;
Ingo Molnar48f24c42006-07-03 00:25:40 -07004051
Ingo Molnar41b86e92007-07-09 18:51:58 +02004052 rq = task_rq_lock(p, &flags);
4053 ns = p->se.sum_exec_runtime;
Dmitry Adamushko051a1d12007-12-18 15:21:13 +01004054 if (task_current(rq, p)) {
Ingo Molnara8e504d2007-08-09 11:16:47 +02004055 update_rq_clock(rq);
4056 delta_exec = rq->clock - p->se.exec_start;
Ingo Molnar41b86e92007-07-09 18:51:58 +02004057 if ((s64)delta_exec > 0)
4058 ns += delta_exec;
4059 }
4060 task_rq_unlock(rq, &flags);
Ingo Molnar48f24c42006-07-03 00:25:40 -07004061
Linus Torvalds1da177e2005-04-16 15:20:36 -07004062 return ns;
4063}
4064
4065/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07004066 * Account user cpu time to a process.
4067 * @p: the process that the cpu time gets accounted to
Linus Torvalds1da177e2005-04-16 15:20:36 -07004068 * @cputime: the cpu time spent in user space since the last update
4069 */
4070void account_user_time(struct task_struct *p, cputime_t cputime)
4071{
4072 struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
4073 cputime64_t tmp;
4074
4075 p->utime = cputime_add(p->utime, cputime);
4076
4077 /* Add user time to cpustat. */
4078 tmp = cputime_to_cputime64(cputime);
4079 if (TASK_NICE(p) > 0)
4080 cpustat->nice = cputime64_add(cpustat->nice, tmp);
4081 else
4082 cpustat->user = cputime64_add(cpustat->user, tmp);
4083}
4084
4085/*
Laurent Vivier94886b82007-10-15 17:00:19 +02004086 * Account guest cpu time to a process.
4087 * @p: the process that the cpu time gets accounted to
4088 * @cputime: the cpu time spent in virtual machine since the last update
4089 */
Adrian Bunkf7402e02007-10-29 21:18:10 +01004090static void account_guest_time(struct task_struct *p, cputime_t cputime)
Laurent Vivier94886b82007-10-15 17:00:19 +02004091{
4092 cputime64_t tmp;
4093 struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
4094
4095 tmp = cputime_to_cputime64(cputime);
4096
4097 p->utime = cputime_add(p->utime, cputime);
4098 p->gtime = cputime_add(p->gtime, cputime);
4099
4100 cpustat->user = cputime64_add(cpustat->user, tmp);
4101 cpustat->guest = cputime64_add(cpustat->guest, tmp);
4102}
4103
4104/*
Michael Neulingc66f08b2007-10-18 03:06:34 -07004105 * Account scaled user cpu time to a process.
4106 * @p: the process that the cpu time gets accounted to
4107 * @cputime: the cpu time spent in user space since the last update
4108 */
4109void account_user_time_scaled(struct task_struct *p, cputime_t cputime)
4110{
4111 p->utimescaled = cputime_add(p->utimescaled, cputime);
4112}
4113
4114/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07004115 * Account system cpu time to a process.
4116 * @p: the process that the cpu time gets accounted to
4117 * @hardirq_offset: the offset to subtract from hardirq_count()
4118 * @cputime: the cpu time spent in kernel space since the last update
4119 */
4120void account_system_time(struct task_struct *p, int hardirq_offset,
4121 cputime_t cputime)
4122{
4123 struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
Ingo Molnar70b97a72006-07-03 00:25:42 -07004124 struct rq *rq = this_rq();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004125 cputime64_t tmp;
4126
Harvey Harrison983ed7a2008-04-24 18:17:55 -07004127 if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
4128 account_guest_time(p, cputime);
4129 return;
4130 }
Laurent Vivier94886b82007-10-15 17:00:19 +02004131
Linus Torvalds1da177e2005-04-16 15:20:36 -07004132 p->stime = cputime_add(p->stime, cputime);
4133
4134 /* Add system time to cpustat. */
4135 tmp = cputime_to_cputime64(cputime);
4136 if (hardirq_count() - hardirq_offset)
4137 cpustat->irq = cputime64_add(cpustat->irq, tmp);
4138 else if (softirq_count())
4139 cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
Andrew Mortoncfb52852007-11-14 16:59:45 -08004140 else if (p != rq->idle)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004141 cpustat->system = cputime64_add(cpustat->system, tmp);
Andrew Mortoncfb52852007-11-14 16:59:45 -08004142 else if (atomic_read(&rq->nr_iowait) > 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004143 cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
4144 else
4145 cpustat->idle = cputime64_add(cpustat->idle, tmp);
4146 /* Account for system time used */
4147 acct_update_integrals(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004148}
4149
4150/*
Michael Neulingc66f08b2007-10-18 03:06:34 -07004151 * Account scaled system cpu time to a process.
4152 * @p: the process that the cpu time gets accounted to
4153 * @hardirq_offset: the offset to subtract from hardirq_count()
4154 * @cputime: the cpu time spent in kernel space since the last update
4155 */
4156void account_system_time_scaled(struct task_struct *p, cputime_t cputime)
4157{
4158 p->stimescaled = cputime_add(p->stimescaled, cputime);
4159}
4160
4161/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07004162 * Account for involuntary wait time.
4163 * @p: the process from which the cpu time has been stolen
4164 * @steal: the cpu time spent in involuntary wait
4165 */
4166void account_steal_time(struct task_struct *p, cputime_t steal)
4167{
4168 struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
4169 cputime64_t tmp = cputime_to_cputime64(steal);
Ingo Molnar70b97a72006-07-03 00:25:42 -07004170 struct rq *rq = this_rq();
Linus Torvalds1da177e2005-04-16 15:20:36 -07004171
4172 if (p == rq->idle) {
4173 p->stime = cputime_add(p->stime, steal);
4174 if (atomic_read(&rq->nr_iowait) > 0)
4175 cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
4176 else
4177 cpustat->idle = cputime64_add(cpustat->idle, tmp);
Andrew Mortoncfb52852007-11-14 16:59:45 -08004178 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07004179 cpustat->steal = cputime64_add(cpustat->steal, tmp);
4180}
4181
Christoph Lameter7835b982006-12-10 02:20:22 -08004182/*
4183 * This function gets called by the timer code, with HZ frequency.
4184 * We call it with interrupts disabled.
4185 *
4186 * It also gets called by the fork code, when changing the parent's
4187 * timeslices.
4188 */
4189void scheduler_tick(void)
4190{
Christoph Lameter7835b982006-12-10 02:20:22 -08004191 int cpu = smp_processor_id();
4192 struct rq *rq = cpu_rq(cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02004193 struct task_struct *curr = rq->curr;
Peter Zijlstra3e51f332008-05-03 18:29:28 +02004194
4195 sched_clock_tick();
Christoph Lameter7835b982006-12-10 02:20:22 -08004196
Ingo Molnardd41f592007-07-09 18:51:59 +02004197 spin_lock(&rq->lock);
Peter Zijlstra3e51f332008-05-03 18:29:28 +02004198 update_rq_clock(rq);
Ingo Molnarf1a438d2007-08-09 11:16:45 +02004199 update_cpu_load(rq);
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01004200 curr->sched_class->task_tick(rq, curr, 0);
Ingo Molnardd41f592007-07-09 18:51:59 +02004201 spin_unlock(&rq->lock);
4202
Christoph Lametere418e1c2006-12-10 02:20:23 -08004203#ifdef CONFIG_SMP
Ingo Molnardd41f592007-07-09 18:51:59 +02004204 rq->idle_at_tick = idle_cpu(cpu);
4205 trigger_load_balance(rq, cpu);
Christoph Lametere418e1c2006-12-10 02:20:23 -08004206#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07004207}
4208
Linus Torvalds1da177e2005-04-16 15:20:36 -07004209#if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
4210
Srinivasa Ds43627582008-02-23 15:24:04 -08004211void __kprobes add_preempt_count(int val)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004212{
4213 /*
4214 * Underflow?
4215 */
Ingo Molnar9a11b49a2006-07-03 00:24:33 -07004216 if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
4217 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004218 preempt_count() += val;
4219 /*
4220 * Spinlock count overflowing soon?
4221 */
Miguel Ojeda Sandonis33859f72006-12-10 02:20:38 -08004222 DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
4223 PREEMPT_MASK - 10);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004224}
4225EXPORT_SYMBOL(add_preempt_count);
4226
Srinivasa Ds43627582008-02-23 15:24:04 -08004227void __kprobes sub_preempt_count(int val)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004228{
4229 /*
4230 * Underflow?
4231 */
Ingo Molnar9a11b49a2006-07-03 00:24:33 -07004232 if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
4233 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004234 /*
4235 * Is the spinlock portion underflowing?
4236 */
Ingo Molnar9a11b49a2006-07-03 00:24:33 -07004237 if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
4238 !(preempt_count() & PREEMPT_MASK)))
4239 return;
4240
Linus Torvalds1da177e2005-04-16 15:20:36 -07004241 preempt_count() -= val;
4242}
4243EXPORT_SYMBOL(sub_preempt_count);
4244
4245#endif
4246
4247/*
Ingo Molnardd41f592007-07-09 18:51:59 +02004248 * Print scheduling while atomic bug:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004249 */
Ingo Molnardd41f592007-07-09 18:51:59 +02004250static noinline void __schedule_bug(struct task_struct *prev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004251{
Satyam Sharma838225b2007-10-24 18:23:50 +02004252 struct pt_regs *regs = get_irq_regs();
4253
4254 printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
4255 prev->comm, prev->pid, preempt_count());
4256
Ingo Molnardd41f592007-07-09 18:51:59 +02004257 debug_show_held_locks(prev);
Arjan van de Vene21f5b12008-05-23 09:05:58 -07004258 print_modules();
Ingo Molnardd41f592007-07-09 18:51:59 +02004259 if (irqs_disabled())
4260 print_irqtrace_events(prev);
Satyam Sharma838225b2007-10-24 18:23:50 +02004261
4262 if (regs)
4263 show_regs(regs);
4264 else
4265 dump_stack();
Ingo Molnardd41f592007-07-09 18:51:59 +02004266}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004267
Ingo Molnardd41f592007-07-09 18:51:59 +02004268/*
4269 * Various schedule()-time debugging checks and statistics:
4270 */
4271static inline void schedule_debug(struct task_struct *prev)
4272{
Linus Torvalds1da177e2005-04-16 15:20:36 -07004273 /*
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01004274 * Test if we are atomic. Since do_exit() needs to call into
Linus Torvalds1da177e2005-04-16 15:20:36 -07004275 * schedule() atomically, we ignore that path for now.
4276 * Otherwise, whine if we are scheduling when we should not be.
4277 */
Roel Kluin3f33a7c2008-05-13 23:44:11 +02004278 if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
Ingo Molnardd41f592007-07-09 18:51:59 +02004279 __schedule_bug(prev);
4280
Linus Torvalds1da177e2005-04-16 15:20:36 -07004281 profile_hit(SCHED_PROFILING, __builtin_return_address(0));
4282
Ingo Molnar2d723762007-10-15 17:00:12 +02004283 schedstat_inc(this_rq(), sched_count);
Ingo Molnarb8efb562007-10-15 17:00:10 +02004284#ifdef CONFIG_SCHEDSTATS
4285 if (unlikely(prev->lock_depth >= 0)) {
Ingo Molnar2d723762007-10-15 17:00:12 +02004286 schedstat_inc(this_rq(), bkl_count);
4287 schedstat_inc(prev, sched_info.bkl_count);
Ingo Molnarb8efb562007-10-15 17:00:10 +02004288 }
4289#endif
Ingo Molnardd41f592007-07-09 18:51:59 +02004290}
4291
4292/*
4293 * Pick up the highest-prio task:
4294 */
4295static inline struct task_struct *
Ingo Molnarff95f3d2007-08-09 11:16:49 +02004296pick_next_task(struct rq *rq, struct task_struct *prev)
Ingo Molnardd41f592007-07-09 18:51:59 +02004297{
Ingo Molnar5522d5d2007-10-15 17:00:12 +02004298 const struct sched_class *class;
Ingo Molnardd41f592007-07-09 18:51:59 +02004299 struct task_struct *p;
4300
4301 /*
4302 * Optimization: we know that if all tasks are in
4303 * the fair class we can call that function directly:
4304 */
4305 if (likely(rq->nr_running == rq->cfs.nr_running)) {
Ingo Molnarfb8d4722007-08-09 11:16:48 +02004306 p = fair_sched_class.pick_next_task(rq);
Ingo Molnardd41f592007-07-09 18:51:59 +02004307 if (likely(p))
4308 return p;
4309 }
4310
4311 class = sched_class_highest;
4312 for ( ; ; ) {
Ingo Molnarfb8d4722007-08-09 11:16:48 +02004313 p = class->pick_next_task(rq);
Ingo Molnardd41f592007-07-09 18:51:59 +02004314 if (p)
4315 return p;
4316 /*
4317 * Will never be NULL as the idle class always
4318 * returns a non-NULL p:
4319 */
4320 class = class->next;
4321 }
4322}
4323
4324/*
4325 * schedule() is the main scheduler function.
4326 */
4327asmlinkage void __sched schedule(void)
4328{
4329 struct task_struct *prev, *next;
Harvey Harrison67ca7bd2008-02-15 09:56:36 -08004330 unsigned long *switch_count;
Ingo Molnardd41f592007-07-09 18:51:59 +02004331 struct rq *rq;
Mike Galbraithf333fdc2008-05-12 21:20:55 +02004332 int cpu, hrtick = sched_feat(HRTICK);
Ingo Molnardd41f592007-07-09 18:51:59 +02004333
Linus Torvalds1da177e2005-04-16 15:20:36 -07004334need_resched:
4335 preempt_disable();
Ingo Molnardd41f592007-07-09 18:51:59 +02004336 cpu = smp_processor_id();
4337 rq = cpu_rq(cpu);
4338 rcu_qsctr_inc(cpu);
4339 prev = rq->curr;
4340 switch_count = &prev->nivcsw;
4341
Linus Torvalds1da177e2005-04-16 15:20:36 -07004342 release_kernel_lock(prev);
4343need_resched_nonpreemptible:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004344
Ingo Molnardd41f592007-07-09 18:51:59 +02004345 schedule_debug(prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004346
Mike Galbraithf333fdc2008-05-12 21:20:55 +02004347 if (hrtick)
4348 hrtick_clear(rq);
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01004349
Ingo Molnar1e819952007-10-15 17:00:13 +02004350 /*
4351 * Do the rq-clock update outside the rq lock:
4352 */
4353 local_irq_disable();
Peter Zijlstra3e51f332008-05-03 18:29:28 +02004354 update_rq_clock(rq);
Ingo Molnar1e819952007-10-15 17:00:13 +02004355 spin_lock(&rq->lock);
4356 clear_tsk_need_resched(prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004357
Ingo Molnardd41f592007-07-09 18:51:59 +02004358 if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
Oleg Nesterov16882c12008-06-08 21:20:41 +04004359 if (unlikely(signal_pending_state(prev->state, prev)))
Ingo Molnardd41f592007-07-09 18:51:59 +02004360 prev->state = TASK_RUNNING;
Oleg Nesterov16882c12008-06-08 21:20:41 +04004361 else
Ingo Molnar2e1cb742007-08-09 11:16:49 +02004362 deactivate_task(rq, prev, 1);
Ingo Molnardd41f592007-07-09 18:51:59 +02004363 switch_count = &prev->nvcsw;
4364 }
4365
Steven Rostedt9a897c52008-01-25 21:08:22 +01004366#ifdef CONFIG_SMP
4367 if (prev->sched_class->pre_schedule)
4368 prev->sched_class->pre_schedule(rq, prev);
4369#endif
Steven Rostedtf65eda42008-01-25 21:08:07 +01004370
Ingo Molnardd41f592007-07-09 18:51:59 +02004371 if (unlikely(!rq->nr_running))
4372 idle_balance(cpu, rq);
4373
Ingo Molnar31ee5292007-08-09 11:16:49 +02004374 prev->sched_class->put_prev_task(rq, prev);
Ingo Molnarff95f3d2007-08-09 11:16:49 +02004375 next = pick_next_task(rq, prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004376
Linus Torvalds1da177e2005-04-16 15:20:36 -07004377 if (likely(prev != next)) {
David Simner673a90a2008-04-29 10:08:59 +01004378 sched_info_switch(prev, next);
4379
Linus Torvalds1da177e2005-04-16 15:20:36 -07004380 rq->nr_switches++;
4381 rq->curr = next;
4382 ++*switch_count;
4383
Ingo Molnardd41f592007-07-09 18:51:59 +02004384 context_switch(rq, prev, next); /* unlocks the rq */
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01004385 /*
4386 * the context switch might have flipped the stack from under
4387 * us, hence refresh the local variables.
4388 */
4389 cpu = smp_processor_id();
4390 rq = cpu_rq(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004391 } else
4392 spin_unlock_irq(&rq->lock);
4393
Mike Galbraithf333fdc2008-05-12 21:20:55 +02004394 if (hrtick)
4395 hrtick_set(rq);
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01004396
4397 if (unlikely(reacquire_kernel_lock(current) < 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004398 goto need_resched_nonpreemptible;
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01004399
Linus Torvalds1da177e2005-04-16 15:20:36 -07004400 preempt_enable_no_resched();
4401 if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
4402 goto need_resched;
4403}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004404EXPORT_SYMBOL(schedule);
4405
4406#ifdef CONFIG_PREEMPT
4407/*
Andreas Mohr2ed6e342006-07-10 04:43:52 -07004408 * this is the entry point to schedule() from in-kernel preemption
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01004409 * off of preempt_enable. Kernel preemptions off return from interrupt
Linus Torvalds1da177e2005-04-16 15:20:36 -07004410 * occur there and call schedule directly.
4411 */
4412asmlinkage void __sched preempt_schedule(void)
4413{
4414 struct thread_info *ti = current_thread_info();
Ingo Molnar6478d882008-01-25 21:08:33 +01004415
Linus Torvalds1da177e2005-04-16 15:20:36 -07004416 /*
4417 * If there is a non-zero preempt_count or interrupts are disabled,
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01004418 * we do not want to preempt the current task. Just return..
Linus Torvalds1da177e2005-04-16 15:20:36 -07004419 */
Nick Pigginbeed33a2006-10-11 01:21:52 -07004420 if (likely(ti->preempt_count || irqs_disabled()))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004421 return;
4422
Andi Kleen3a5c3592007-10-15 17:00:14 +02004423 do {
4424 add_preempt_count(PREEMPT_ACTIVE);
Andi Kleen3a5c3592007-10-15 17:00:14 +02004425 schedule();
Andi Kleen3a5c3592007-10-15 17:00:14 +02004426 sub_preempt_count(PREEMPT_ACTIVE);
4427
4428 /*
4429 * Check again in case we missed a preemption opportunity
4430 * between schedule and now.
4431 */
4432 barrier();
4433 } while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004434}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004435EXPORT_SYMBOL(preempt_schedule);
4436
4437/*
Andreas Mohr2ed6e342006-07-10 04:43:52 -07004438 * this is the entry point to schedule() from kernel preemption
Linus Torvalds1da177e2005-04-16 15:20:36 -07004439 * off of irq context.
4440 * Note, that this is called and return with irqs disabled. This will
4441 * protect us against recursive calling from irq.
4442 */
4443asmlinkage void __sched preempt_schedule_irq(void)
4444{
4445 struct thread_info *ti = current_thread_info();
Ingo Molnar6478d882008-01-25 21:08:33 +01004446
Andreas Mohr2ed6e342006-07-10 04:43:52 -07004447 /* Catch callers which need to be fixed */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004448 BUG_ON(ti->preempt_count || !irqs_disabled());
4449
Andi Kleen3a5c3592007-10-15 17:00:14 +02004450 do {
4451 add_preempt_count(PREEMPT_ACTIVE);
Andi Kleen3a5c3592007-10-15 17:00:14 +02004452 local_irq_enable();
4453 schedule();
4454 local_irq_disable();
Andi Kleen3a5c3592007-10-15 17:00:14 +02004455 sub_preempt_count(PREEMPT_ACTIVE);
4456
4457 /*
4458 * Check again in case we missed a preemption opportunity
4459 * between schedule and now.
4460 */
4461 barrier();
4462 } while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004463}
4464
4465#endif /* CONFIG_PREEMPT */
4466
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07004467int default_wake_function(wait_queue_t *curr, unsigned mode, int sync,
4468 void *key)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004469{
Ingo Molnar48f24c42006-07-03 00:25:40 -07004470 return try_to_wake_up(curr->private, mode, sync);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004471}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004472EXPORT_SYMBOL(default_wake_function);
4473
4474/*
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01004475 * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
4476 * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
Linus Torvalds1da177e2005-04-16 15:20:36 -07004477 * number) then we wake all the non-exclusive tasks and one exclusive task.
4478 *
4479 * There are circumstances in which we can try to wake a task which has already
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01004480 * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
Linus Torvalds1da177e2005-04-16 15:20:36 -07004481 * zero in this (rare) case, and we handle it by continuing to scan the queue.
4482 */
4483static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
4484 int nr_exclusive, int sync, void *key)
4485{
Matthias Kaehlcke2e458742007-10-15 17:00:02 +02004486 wait_queue_t *curr, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004487
Matthias Kaehlcke2e458742007-10-15 17:00:02 +02004488 list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
Ingo Molnar48f24c42006-07-03 00:25:40 -07004489 unsigned flags = curr->flags;
4490
Linus Torvalds1da177e2005-04-16 15:20:36 -07004491 if (curr->func(curr, mode, sync, key) &&
Ingo Molnar48f24c42006-07-03 00:25:40 -07004492 (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004493 break;
4494 }
4495}
4496
4497/**
4498 * __wake_up - wake up threads blocked on a waitqueue.
4499 * @q: the waitqueue
4500 * @mode: which threads
4501 * @nr_exclusive: how many wake-one or wake-many threads to wake up
Martin Waitz67be2dd2005-05-01 08:59:26 -07004502 * @key: is directly passed to the wakeup function
Linus Torvalds1da177e2005-04-16 15:20:36 -07004503 */
Harvey Harrison7ad5b3a2008-02-08 04:19:53 -08004504void __wake_up(wait_queue_head_t *q, unsigned int mode,
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07004505 int nr_exclusive, void *key)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004506{
4507 unsigned long flags;
4508
4509 spin_lock_irqsave(&q->lock, flags);
4510 __wake_up_common(q, mode, nr_exclusive, 0, key);
4511 spin_unlock_irqrestore(&q->lock, flags);
4512}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004513EXPORT_SYMBOL(__wake_up);
4514
4515/*
4516 * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
4517 */
Harvey Harrison7ad5b3a2008-02-08 04:19:53 -08004518void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004519{
4520 __wake_up_common(q, mode, 1, 0, NULL);
4521}
4522
4523/**
Martin Waitz67be2dd2005-05-01 08:59:26 -07004524 * __wake_up_sync - wake up threads blocked on a waitqueue.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004525 * @q: the waitqueue
4526 * @mode: which threads
4527 * @nr_exclusive: how many wake-one or wake-many threads to wake up
4528 *
4529 * The sync wakeup differs that the waker knows that it will schedule
4530 * away soon, so while the target thread will be woken up, it will not
4531 * be migrated to another CPU - ie. the two threads are 'synchronized'
4532 * with each other. This can prevent needless bouncing between CPUs.
4533 *
4534 * On UP it can prevent extra preemption.
4535 */
Harvey Harrison7ad5b3a2008-02-08 04:19:53 -08004536void
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07004537__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004538{
4539 unsigned long flags;
4540 int sync = 1;
4541
4542 if (unlikely(!q))
4543 return;
4544
4545 if (unlikely(!nr_exclusive))
4546 sync = 0;
4547
4548 spin_lock_irqsave(&q->lock, flags);
4549 __wake_up_common(q, mode, nr_exclusive, sync, NULL);
4550 spin_unlock_irqrestore(&q->lock, flags);
4551}
4552EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
4553
Ingo Molnarb15136e2007-10-24 18:23:48 +02004554void complete(struct completion *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004555{
4556 unsigned long flags;
4557
4558 spin_lock_irqsave(&x->wait.lock, flags);
4559 x->done++;
Matthew Wilcoxd9514f62007-12-06 11:07:07 -05004560 __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004561 spin_unlock_irqrestore(&x->wait.lock, flags);
4562}
4563EXPORT_SYMBOL(complete);
4564
Ingo Molnarb15136e2007-10-24 18:23:48 +02004565void complete_all(struct completion *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004566{
4567 unsigned long flags;
4568
4569 spin_lock_irqsave(&x->wait.lock, flags);
4570 x->done += UINT_MAX/2;
Matthew Wilcoxd9514f62007-12-06 11:07:07 -05004571 __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004572 spin_unlock_irqrestore(&x->wait.lock, flags);
4573}
4574EXPORT_SYMBOL(complete_all);
4575
Andi Kleen8cbbe862007-10-15 17:00:14 +02004576static inline long __sched
4577do_wait_for_common(struct completion *x, long timeout, int state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004578{
Linus Torvalds1da177e2005-04-16 15:20:36 -07004579 if (!x->done) {
4580 DECLARE_WAITQUEUE(wait, current);
4581
4582 wait.flags |= WQ_FLAG_EXCLUSIVE;
4583 __add_wait_queue_tail(&x->wait, &wait);
4584 do {
Matthew Wilcox009e5772007-12-06 12:29:54 -05004585 if ((state == TASK_INTERRUPTIBLE &&
4586 signal_pending(current)) ||
4587 (state == TASK_KILLABLE &&
4588 fatal_signal_pending(current))) {
Oleg Nesterovea71a542008-06-20 18:32:20 +04004589 timeout = -ERESTARTSYS;
4590 break;
Andi Kleen8cbbe862007-10-15 17:00:14 +02004591 }
4592 __set_current_state(state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004593 spin_unlock_irq(&x->wait.lock);
Andi Kleen8cbbe862007-10-15 17:00:14 +02004594 timeout = schedule_timeout(timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004595 spin_lock_irq(&x->wait.lock);
Oleg Nesterovea71a542008-06-20 18:32:20 +04004596 } while (!x->done && timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004597 __remove_wait_queue(&x->wait, &wait);
Oleg Nesterovea71a542008-06-20 18:32:20 +04004598 if (!x->done)
4599 return timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004600 }
4601 x->done--;
Oleg Nesterovea71a542008-06-20 18:32:20 +04004602 return timeout ?: 1;
Andi Kleen8cbbe862007-10-15 17:00:14 +02004603}
4604
4605static long __sched
4606wait_for_common(struct completion *x, long timeout, int state)
4607{
4608 might_sleep();
4609
4610 spin_lock_irq(&x->wait.lock);
4611 timeout = do_wait_for_common(x, timeout, state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004612 spin_unlock_irq(&x->wait.lock);
Andi Kleen8cbbe862007-10-15 17:00:14 +02004613 return timeout;
4614}
4615
Ingo Molnarb15136e2007-10-24 18:23:48 +02004616void __sched wait_for_completion(struct completion *x)
Andi Kleen8cbbe862007-10-15 17:00:14 +02004617{
4618 wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004619}
4620EXPORT_SYMBOL(wait_for_completion);
4621
Ingo Molnarb15136e2007-10-24 18:23:48 +02004622unsigned long __sched
Linus Torvalds1da177e2005-04-16 15:20:36 -07004623wait_for_completion_timeout(struct completion *x, unsigned long timeout)
4624{
Andi Kleen8cbbe862007-10-15 17:00:14 +02004625 return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004626}
4627EXPORT_SYMBOL(wait_for_completion_timeout);
4628
Andi Kleen8cbbe862007-10-15 17:00:14 +02004629int __sched wait_for_completion_interruptible(struct completion *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004630{
Andi Kleen51e97992007-10-18 21:32:55 +02004631 long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
4632 if (t == -ERESTARTSYS)
4633 return t;
4634 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004635}
4636EXPORT_SYMBOL(wait_for_completion_interruptible);
4637
Ingo Molnarb15136e2007-10-24 18:23:48 +02004638unsigned long __sched
Linus Torvalds1da177e2005-04-16 15:20:36 -07004639wait_for_completion_interruptible_timeout(struct completion *x,
4640 unsigned long timeout)
4641{
Andi Kleen8cbbe862007-10-15 17:00:14 +02004642 return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004643}
4644EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
4645
Matthew Wilcox009e5772007-12-06 12:29:54 -05004646int __sched wait_for_completion_killable(struct completion *x)
4647{
4648 long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
4649 if (t == -ERESTARTSYS)
4650 return t;
4651 return 0;
4652}
4653EXPORT_SYMBOL(wait_for_completion_killable);
4654
Andi Kleen8cbbe862007-10-15 17:00:14 +02004655static long __sched
4656sleep_on_common(wait_queue_head_t *q, int state, long timeout)
Ingo Molnar0fec1712007-07-09 18:52:01 +02004657{
4658 unsigned long flags;
4659 wait_queue_t wait;
4660
4661 init_waitqueue_entry(&wait, current);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004662
Andi Kleen8cbbe862007-10-15 17:00:14 +02004663 __set_current_state(state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004664
Andi Kleen8cbbe862007-10-15 17:00:14 +02004665 spin_lock_irqsave(&q->lock, flags);
4666 __add_wait_queue(q, &wait);
4667 spin_unlock(&q->lock);
4668 timeout = schedule_timeout(timeout);
4669 spin_lock_irq(&q->lock);
4670 __remove_wait_queue(q, &wait);
4671 spin_unlock_irqrestore(&q->lock, flags);
4672
4673 return timeout;
4674}
4675
4676void __sched interruptible_sleep_on(wait_queue_head_t *q)
4677{
4678 sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004679}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004680EXPORT_SYMBOL(interruptible_sleep_on);
4681
Ingo Molnar0fec1712007-07-09 18:52:01 +02004682long __sched
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07004683interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004684{
Andi Kleen8cbbe862007-10-15 17:00:14 +02004685 return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004686}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004687EXPORT_SYMBOL(interruptible_sleep_on_timeout);
4688
Ingo Molnar0fec1712007-07-09 18:52:01 +02004689void __sched sleep_on(wait_queue_head_t *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004690{
Andi Kleen8cbbe862007-10-15 17:00:14 +02004691 sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004692}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004693EXPORT_SYMBOL(sleep_on);
4694
Ingo Molnar0fec1712007-07-09 18:52:01 +02004695long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004696{
Andi Kleen8cbbe862007-10-15 17:00:14 +02004697 return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004698}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004699EXPORT_SYMBOL(sleep_on_timeout);
4700
Ingo Molnarb29739f2006-06-27 02:54:51 -07004701#ifdef CONFIG_RT_MUTEXES
4702
4703/*
4704 * rt_mutex_setprio - set the current priority of a task
4705 * @p: task
4706 * @prio: prio value (kernel-internal form)
4707 *
4708 * This function changes the 'effective' priority of a task. It does
4709 * not touch ->normal_prio like __setscheduler().
4710 *
4711 * Used by the rt_mutex code to implement priority inheritance logic.
4712 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07004713void rt_mutex_setprio(struct task_struct *p, int prio)
Ingo Molnarb29739f2006-06-27 02:54:51 -07004714{
4715 unsigned long flags;
Srivatsa Vaddagiri83b699e2007-10-15 17:00:08 +02004716 int oldprio, on_rq, running;
Ingo Molnar70b97a72006-07-03 00:25:42 -07004717 struct rq *rq;
Steven Rostedtcb469842008-01-25 21:08:22 +01004718 const struct sched_class *prev_class = p->sched_class;
Ingo Molnarb29739f2006-06-27 02:54:51 -07004719
4720 BUG_ON(prio < 0 || prio > MAX_PRIO);
4721
4722 rq = task_rq_lock(p, &flags);
Ingo Molnara8e504d2007-08-09 11:16:47 +02004723 update_rq_clock(rq);
Ingo Molnarb29739f2006-06-27 02:54:51 -07004724
Andrew Mortond5f9f942007-05-08 20:27:06 -07004725 oldprio = p->prio;
Ingo Molnardd41f592007-07-09 18:51:59 +02004726 on_rq = p->se.on_rq;
Dmitry Adamushko051a1d12007-12-18 15:21:13 +01004727 running = task_current(rq, p);
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07004728 if (on_rq)
Ingo Molnar69be72c2007-08-09 11:16:49 +02004729 dequeue_task(rq, p, 0);
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07004730 if (running)
4731 p->sched_class->put_prev_task(rq, p);
Ingo Molnardd41f592007-07-09 18:51:59 +02004732
4733 if (rt_prio(prio))
4734 p->sched_class = &rt_sched_class;
4735 else
4736 p->sched_class = &fair_sched_class;
4737
Ingo Molnarb29739f2006-06-27 02:54:51 -07004738 p->prio = prio;
4739
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07004740 if (running)
4741 p->sched_class->set_curr_task(rq);
Ingo Molnardd41f592007-07-09 18:51:59 +02004742 if (on_rq) {
Ingo Molnar8159f872007-08-09 11:16:49 +02004743 enqueue_task(rq, p, 0);
Steven Rostedtcb469842008-01-25 21:08:22 +01004744
4745 check_class_changed(rq, p, prev_class, oldprio, running);
Ingo Molnarb29739f2006-06-27 02:54:51 -07004746 }
4747 task_rq_unlock(rq, &flags);
4748}
4749
4750#endif
4751
Ingo Molnar36c8b582006-07-03 00:25:41 -07004752void set_user_nice(struct task_struct *p, long nice)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004753{
Ingo Molnardd41f592007-07-09 18:51:59 +02004754 int old_prio, delta, on_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004755 unsigned long flags;
Ingo Molnar70b97a72006-07-03 00:25:42 -07004756 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004757
4758 if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
4759 return;
4760 /*
4761 * We have to be careful, if called from sys_setpriority(),
4762 * the task might be in the middle of scheduling on another CPU.
4763 */
4764 rq = task_rq_lock(p, &flags);
Ingo Molnara8e504d2007-08-09 11:16:47 +02004765 update_rq_clock(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004766 /*
4767 * The RT priorities are set via sched_setscheduler(), but we still
4768 * allow the 'normal' nice value to be set - but as expected
4769 * it wont have any effect on scheduling until the task is
Ingo Molnardd41f592007-07-09 18:51:59 +02004770 * SCHED_FIFO/SCHED_RR:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004771 */
Ingo Molnare05606d2007-07-09 18:51:59 +02004772 if (task_has_rt_policy(p)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07004773 p->static_prio = NICE_TO_PRIO(nice);
4774 goto out_unlock;
4775 }
Ingo Molnardd41f592007-07-09 18:51:59 +02004776 on_rq = p->se.on_rq;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02004777 if (on_rq)
Ingo Molnar69be72c2007-08-09 11:16:49 +02004778 dequeue_task(rq, p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004779
Linus Torvalds1da177e2005-04-16 15:20:36 -07004780 p->static_prio = NICE_TO_PRIO(nice);
Peter Williams2dd73a42006-06-27 02:54:34 -07004781 set_load_weight(p);
Ingo Molnarb29739f2006-06-27 02:54:51 -07004782 old_prio = p->prio;
4783 p->prio = effective_prio(p);
4784 delta = p->prio - old_prio;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004785
Ingo Molnardd41f592007-07-09 18:51:59 +02004786 if (on_rq) {
Ingo Molnar8159f872007-08-09 11:16:49 +02004787 enqueue_task(rq, p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004788 /*
Andrew Mortond5f9f942007-05-08 20:27:06 -07004789 * If the task increased its priority or is running and
4790 * lowered its priority, then reschedule its CPU:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004791 */
Andrew Mortond5f9f942007-05-08 20:27:06 -07004792 if (delta < 0 || (delta > 0 && task_running(rq, p)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004793 resched_task(rq->curr);
4794 }
4795out_unlock:
4796 task_rq_unlock(rq, &flags);
4797}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004798EXPORT_SYMBOL(set_user_nice);
4799
Matt Mackalle43379f2005-05-01 08:59:00 -07004800/*
4801 * can_nice - check if a task can reduce its nice value
4802 * @p: task
4803 * @nice: nice value
4804 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07004805int can_nice(const struct task_struct *p, const int nice)
Matt Mackalle43379f2005-05-01 08:59:00 -07004806{
Matt Mackall024f4742005-08-18 11:24:19 -07004807 /* convert nice value [19,-20] to rlimit style value [1,40] */
4808 int nice_rlim = 20 - nice;
Ingo Molnar48f24c42006-07-03 00:25:40 -07004809
Matt Mackalle43379f2005-05-01 08:59:00 -07004810 return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
4811 capable(CAP_SYS_NICE));
4812}
4813
Linus Torvalds1da177e2005-04-16 15:20:36 -07004814#ifdef __ARCH_WANT_SYS_NICE
4815
4816/*
4817 * sys_nice - change the priority of the current process.
4818 * @increment: priority increment
4819 *
4820 * sys_setpriority is a more generic, but much slower function that
4821 * does similar things.
4822 */
4823asmlinkage long sys_nice(int increment)
4824{
Ingo Molnar48f24c42006-07-03 00:25:40 -07004825 long nice, retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004826
4827 /*
4828 * Setpriority might change our priority at the same moment.
4829 * We don't have to worry. Conceptually one call occurs first
4830 * and we have a single winner.
4831 */
Matt Mackalle43379f2005-05-01 08:59:00 -07004832 if (increment < -40)
4833 increment = -40;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004834 if (increment > 40)
4835 increment = 40;
4836
4837 nice = PRIO_TO_NICE(current->static_prio) + increment;
4838 if (nice < -20)
4839 nice = -20;
4840 if (nice > 19)
4841 nice = 19;
4842
Matt Mackalle43379f2005-05-01 08:59:00 -07004843 if (increment < 0 && !can_nice(current, nice))
4844 return -EPERM;
4845
Linus Torvalds1da177e2005-04-16 15:20:36 -07004846 retval = security_task_setnice(current, nice);
4847 if (retval)
4848 return retval;
4849
4850 set_user_nice(current, nice);
4851 return 0;
4852}
4853
4854#endif
4855
4856/**
4857 * task_prio - return the priority value of a given task.
4858 * @p: the task in question.
4859 *
4860 * This is the priority value as seen by users in /proc.
4861 * RT tasks are offset by -200. Normal tasks are centered
4862 * around 0, value goes from -16 to +15.
4863 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07004864int task_prio(const struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004865{
4866 return p->prio - MAX_RT_PRIO;
4867}
4868
4869/**
4870 * task_nice - return the nice value of a given task.
4871 * @p: the task in question.
4872 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07004873int task_nice(const struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004874{
4875 return TASK_NICE(p);
4876}
Pavel Roskin150d8be2008-03-05 16:56:37 -05004877EXPORT_SYMBOL(task_nice);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004878
4879/**
4880 * idle_cpu - is a given cpu idle currently?
4881 * @cpu: the processor in question.
4882 */
4883int idle_cpu(int cpu)
4884{
4885 return cpu_curr(cpu) == cpu_rq(cpu)->idle;
4886}
4887
Linus Torvalds1da177e2005-04-16 15:20:36 -07004888/**
4889 * idle_task - return the idle task for a given cpu.
4890 * @cpu: the processor in question.
4891 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07004892struct task_struct *idle_task(int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004893{
4894 return cpu_rq(cpu)->idle;
4895}
4896
4897/**
4898 * find_process_by_pid - find a process with a matching PID value.
4899 * @pid: the pid in question.
4900 */
Alexey Dobriyana9957442007-10-15 17:00:13 +02004901static struct task_struct *find_process_by_pid(pid_t pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004902{
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -07004903 return pid ? find_task_by_vpid(pid) : current;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004904}
4905
4906/* Actually do priority change: must hold rq lock. */
Ingo Molnardd41f592007-07-09 18:51:59 +02004907static void
4908__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004909{
Ingo Molnardd41f592007-07-09 18:51:59 +02004910 BUG_ON(p->se.on_rq);
Ingo Molnar48f24c42006-07-03 00:25:40 -07004911
Linus Torvalds1da177e2005-04-16 15:20:36 -07004912 p->policy = policy;
Ingo Molnardd41f592007-07-09 18:51:59 +02004913 switch (p->policy) {
4914 case SCHED_NORMAL:
4915 case SCHED_BATCH:
4916 case SCHED_IDLE:
4917 p->sched_class = &fair_sched_class;
4918 break;
4919 case SCHED_FIFO:
4920 case SCHED_RR:
4921 p->sched_class = &rt_sched_class;
4922 break;
4923 }
4924
Linus Torvalds1da177e2005-04-16 15:20:36 -07004925 p->rt_priority = prio;
Ingo Molnarb29739f2006-06-27 02:54:51 -07004926 p->normal_prio = normal_prio(p);
4927 /* we are holding p->pi_lock already */
4928 p->prio = rt_mutex_getprio(p);
Peter Williams2dd73a42006-06-27 02:54:34 -07004929 set_load_weight(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004930}
4931
4932/**
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08004933 * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004934 * @p: the task in question.
4935 * @policy: new policy.
4936 * @param: structure containing the new RT priority.
Oleg Nesterov5fe1d752006-09-29 02:00:48 -07004937 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08004938 * NOTE that the task may be already dead.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004939 */
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07004940int sched_setscheduler(struct task_struct *p, int policy,
4941 struct sched_param *param)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004942{
Srivatsa Vaddagiri83b699e2007-10-15 17:00:08 +02004943 int retval, oldprio, oldpolicy = -1, on_rq, running;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004944 unsigned long flags;
Steven Rostedtcb469842008-01-25 21:08:22 +01004945 const struct sched_class *prev_class = p->sched_class;
Ingo Molnar70b97a72006-07-03 00:25:42 -07004946 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004947
Steven Rostedt66e53932006-06-27 02:54:44 -07004948 /* may grab non-irq protected spin_locks */
4949 BUG_ON(in_interrupt());
Linus Torvalds1da177e2005-04-16 15:20:36 -07004950recheck:
4951 /* double check policy once rq lock held */
4952 if (policy < 0)
4953 policy = oldpolicy = p->policy;
4954 else if (policy != SCHED_FIFO && policy != SCHED_RR &&
Ingo Molnardd41f592007-07-09 18:51:59 +02004955 policy != SCHED_NORMAL && policy != SCHED_BATCH &&
4956 policy != SCHED_IDLE)
Ingo Molnarb0a94992006-01-14 13:20:41 -08004957 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004958 /*
4959 * Valid priorities for SCHED_FIFO and SCHED_RR are
Ingo Molnardd41f592007-07-09 18:51:59 +02004960 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
4961 * SCHED_BATCH and SCHED_IDLE is 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004962 */
4963 if (param->sched_priority < 0 ||
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07004964 (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
Steven Rostedtd46523e2005-07-25 16:28:39 -04004965 (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004966 return -EINVAL;
Ingo Molnare05606d2007-07-09 18:51:59 +02004967 if (rt_policy(policy) != (param->sched_priority != 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -07004968 return -EINVAL;
4969
Olivier Croquette37e4ab32005-06-25 14:57:32 -07004970 /*
4971 * Allow unprivileged RT tasks to decrease priority:
4972 */
4973 if (!capable(CAP_SYS_NICE)) {
Ingo Molnare05606d2007-07-09 18:51:59 +02004974 if (rt_policy(policy)) {
Oleg Nesterov8dc3e902006-09-29 02:00:50 -07004975 unsigned long rlim_rtprio;
Oleg Nesterov5fe1d752006-09-29 02:00:48 -07004976
Oleg Nesterov8dc3e902006-09-29 02:00:50 -07004977 if (!lock_task_sighand(p, &flags))
4978 return -ESRCH;
4979 rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
4980 unlock_task_sighand(p, &flags);
Oleg Nesterov5fe1d752006-09-29 02:00:48 -07004981
Oleg Nesterov8dc3e902006-09-29 02:00:50 -07004982 /* can't set/change the rt policy */
4983 if (policy != p->policy && !rlim_rtprio)
4984 return -EPERM;
4985
4986 /* can't increase priority */
4987 if (param->sched_priority > p->rt_priority &&
4988 param->sched_priority > rlim_rtprio)
4989 return -EPERM;
4990 }
Ingo Molnardd41f592007-07-09 18:51:59 +02004991 /*
4992 * Like positive nice levels, dont allow tasks to
4993 * move out of SCHED_IDLE either:
4994 */
4995 if (p->policy == SCHED_IDLE && policy != SCHED_IDLE)
4996 return -EPERM;
Oleg Nesterov8dc3e902006-09-29 02:00:50 -07004997
Olivier Croquette37e4ab32005-06-25 14:57:32 -07004998 /* can't change other user's priorities */
4999 if ((current->euid != p->euid) &&
5000 (current->euid != p->uid))
5001 return -EPERM;
5002 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005003
Peter Zijlstrab68aa232008-02-13 15:45:40 +01005004#ifdef CONFIG_RT_GROUP_SCHED
5005 /*
5006 * Do not allow realtime tasks into groups that have no runtime
5007 * assigned.
5008 */
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02005009 if (rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0)
Peter Zijlstrab68aa232008-02-13 15:45:40 +01005010 return -EPERM;
5011#endif
5012
Linus Torvalds1da177e2005-04-16 15:20:36 -07005013 retval = security_task_setscheduler(p, policy, param);
5014 if (retval)
5015 return retval;
5016 /*
Ingo Molnarb29739f2006-06-27 02:54:51 -07005017 * make sure no PI-waiters arrive (or leave) while we are
5018 * changing the priority of the task:
5019 */
5020 spin_lock_irqsave(&p->pi_lock, flags);
5021 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07005022 * To be able to change p->policy safely, the apropriate
5023 * runqueue lock must be held.
5024 */
Ingo Molnarb29739f2006-06-27 02:54:51 -07005025 rq = __task_rq_lock(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005026 /* recheck policy now with rq lock held */
5027 if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
5028 policy = oldpolicy = -1;
Ingo Molnarb29739f2006-06-27 02:54:51 -07005029 __task_rq_unlock(rq);
5030 spin_unlock_irqrestore(&p->pi_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005031 goto recheck;
5032 }
Ingo Molnar2daa3572007-08-09 11:16:51 +02005033 update_rq_clock(rq);
Ingo Molnardd41f592007-07-09 18:51:59 +02005034 on_rq = p->se.on_rq;
Dmitry Adamushko051a1d12007-12-18 15:21:13 +01005035 running = task_current(rq, p);
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07005036 if (on_rq)
Ingo Molnar2e1cb742007-08-09 11:16:49 +02005037 deactivate_task(rq, p, 0);
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07005038 if (running)
5039 p->sched_class->put_prev_task(rq, p);
Dmitry Adamushkof6b53202007-10-15 17:00:08 +02005040
Linus Torvalds1da177e2005-04-16 15:20:36 -07005041 oldprio = p->prio;
Ingo Molnardd41f592007-07-09 18:51:59 +02005042 __setscheduler(rq, p, policy, param->sched_priority);
Dmitry Adamushkof6b53202007-10-15 17:00:08 +02005043
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07005044 if (running)
5045 p->sched_class->set_curr_task(rq);
Ingo Molnardd41f592007-07-09 18:51:59 +02005046 if (on_rq) {
5047 activate_task(rq, p, 0);
Steven Rostedtcb469842008-01-25 21:08:22 +01005048
5049 check_class_changed(rq, p, prev_class, oldprio, running);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005050 }
Ingo Molnarb29739f2006-06-27 02:54:51 -07005051 __task_rq_unlock(rq);
5052 spin_unlock_irqrestore(&p->pi_lock, flags);
5053
Thomas Gleixner95e02ca2006-06-27 02:55:02 -07005054 rt_mutex_adjust_pi(p);
5055
Linus Torvalds1da177e2005-04-16 15:20:36 -07005056 return 0;
5057}
5058EXPORT_SYMBOL_GPL(sched_setscheduler);
5059
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07005060static int
5061do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005062{
Linus Torvalds1da177e2005-04-16 15:20:36 -07005063 struct sched_param lparam;
5064 struct task_struct *p;
Ingo Molnar36c8b582006-07-03 00:25:41 -07005065 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005066
5067 if (!param || pid < 0)
5068 return -EINVAL;
5069 if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
5070 return -EFAULT;
Oleg Nesterov5fe1d752006-09-29 02:00:48 -07005071
5072 rcu_read_lock();
5073 retval = -ESRCH;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005074 p = find_process_by_pid(pid);
Oleg Nesterov5fe1d752006-09-29 02:00:48 -07005075 if (p != NULL)
5076 retval = sched_setscheduler(p, policy, &lparam);
5077 rcu_read_unlock();
Ingo Molnar36c8b582006-07-03 00:25:41 -07005078
Linus Torvalds1da177e2005-04-16 15:20:36 -07005079 return retval;
5080}
5081
5082/**
5083 * sys_sched_setscheduler - set/change the scheduler policy and RT priority
5084 * @pid: the pid in question.
5085 * @policy: new policy.
5086 * @param: structure containing the new RT priority.
5087 */
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005088asmlinkage long
5089sys_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005090{
Jason Baronc21761f2006-01-18 17:43:03 -08005091 /* negative values for policy are not valid */
5092 if (policy < 0)
5093 return -EINVAL;
5094
Linus Torvalds1da177e2005-04-16 15:20:36 -07005095 return do_sched_setscheduler(pid, policy, param);
5096}
5097
5098/**
5099 * sys_sched_setparam - set/change the RT priority of a thread
5100 * @pid: the pid in question.
5101 * @param: structure containing the new RT priority.
5102 */
5103asmlinkage long sys_sched_setparam(pid_t pid, struct sched_param __user *param)
5104{
5105 return do_sched_setscheduler(pid, -1, param);
5106}
5107
5108/**
5109 * sys_sched_getscheduler - get the policy (scheduling class) of a thread
5110 * @pid: the pid in question.
5111 */
5112asmlinkage long sys_sched_getscheduler(pid_t pid)
5113{
Ingo Molnar36c8b582006-07-03 00:25:41 -07005114 struct task_struct *p;
Andi Kleen3a5c3592007-10-15 17:00:14 +02005115 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005116
5117 if (pid < 0)
Andi Kleen3a5c3592007-10-15 17:00:14 +02005118 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005119
5120 retval = -ESRCH;
5121 read_lock(&tasklist_lock);
5122 p = find_process_by_pid(pid);
5123 if (p) {
5124 retval = security_task_getscheduler(p);
5125 if (!retval)
5126 retval = p->policy;
5127 }
5128 read_unlock(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005129 return retval;
5130}
5131
5132/**
5133 * sys_sched_getscheduler - get the RT priority of a thread
5134 * @pid: the pid in question.
5135 * @param: structure containing the RT priority.
5136 */
5137asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param)
5138{
5139 struct sched_param lp;
Ingo Molnar36c8b582006-07-03 00:25:41 -07005140 struct task_struct *p;
Andi Kleen3a5c3592007-10-15 17:00:14 +02005141 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005142
5143 if (!param || pid < 0)
Andi Kleen3a5c3592007-10-15 17:00:14 +02005144 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005145
5146 read_lock(&tasklist_lock);
5147 p = find_process_by_pid(pid);
5148 retval = -ESRCH;
5149 if (!p)
5150 goto out_unlock;
5151
5152 retval = security_task_getscheduler(p);
5153 if (retval)
5154 goto out_unlock;
5155
5156 lp.sched_priority = p->rt_priority;
5157 read_unlock(&tasklist_lock);
5158
5159 /*
5160 * This one might sleep, we cannot do it with a spinlock held ...
5161 */
5162 retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
5163
Linus Torvalds1da177e2005-04-16 15:20:36 -07005164 return retval;
5165
5166out_unlock:
5167 read_unlock(&tasklist_lock);
5168 return retval;
5169}
5170
Mike Travisb53e9212008-04-04 18:11:08 -07005171long sched_setaffinity(pid_t pid, const cpumask_t *in_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005172{
Linus Torvalds1da177e2005-04-16 15:20:36 -07005173 cpumask_t cpus_allowed;
Mike Travisb53e9212008-04-04 18:11:08 -07005174 cpumask_t new_mask = *in_mask;
Ingo Molnar36c8b582006-07-03 00:25:41 -07005175 struct task_struct *p;
5176 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005177
Gautham R Shenoy95402b32008-01-25 21:08:02 +01005178 get_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005179 read_lock(&tasklist_lock);
5180
5181 p = find_process_by_pid(pid);
5182 if (!p) {
5183 read_unlock(&tasklist_lock);
Gautham R Shenoy95402b32008-01-25 21:08:02 +01005184 put_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005185 return -ESRCH;
5186 }
5187
5188 /*
5189 * It is not safe to call set_cpus_allowed with the
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005190 * tasklist_lock held. We will bump the task_struct's
Linus Torvalds1da177e2005-04-16 15:20:36 -07005191 * usage count and then drop tasklist_lock.
5192 */
5193 get_task_struct(p);
5194 read_unlock(&tasklist_lock);
5195
5196 retval = -EPERM;
5197 if ((current->euid != p->euid) && (current->euid != p->uid) &&
5198 !capable(CAP_SYS_NICE))
5199 goto out_unlock;
5200
David Quigleye7834f82006-06-23 02:03:59 -07005201 retval = security_task_setscheduler(p, 0, NULL);
5202 if (retval)
5203 goto out_unlock;
5204
Mike Travisf9a86fc2008-04-04 18:11:07 -07005205 cpuset_cpus_allowed(p, &cpus_allowed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005206 cpus_and(new_mask, new_mask, cpus_allowed);
Paul Menage8707d8b2007-10-18 23:40:22 -07005207 again:
Mike Travis7c16ec52008-04-04 18:11:11 -07005208 retval = set_cpus_allowed_ptr(p, &new_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005209
Paul Menage8707d8b2007-10-18 23:40:22 -07005210 if (!retval) {
Mike Travisf9a86fc2008-04-04 18:11:07 -07005211 cpuset_cpus_allowed(p, &cpus_allowed);
Paul Menage8707d8b2007-10-18 23:40:22 -07005212 if (!cpus_subset(new_mask, cpus_allowed)) {
5213 /*
5214 * We must have raced with a concurrent cpuset
5215 * update. Just reset the cpus_allowed to the
5216 * cpuset's cpus_allowed
5217 */
5218 new_mask = cpus_allowed;
5219 goto again;
5220 }
5221 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005222out_unlock:
5223 put_task_struct(p);
Gautham R Shenoy95402b32008-01-25 21:08:02 +01005224 put_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005225 return retval;
5226}
5227
5228static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
5229 cpumask_t *new_mask)
5230{
5231 if (len < sizeof(cpumask_t)) {
5232 memset(new_mask, 0, sizeof(cpumask_t));
5233 } else if (len > sizeof(cpumask_t)) {
5234 len = sizeof(cpumask_t);
5235 }
5236 return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
5237}
5238
5239/**
5240 * sys_sched_setaffinity - set the cpu affinity of a process
5241 * @pid: pid of the process
5242 * @len: length in bytes of the bitmask pointed to by user_mask_ptr
5243 * @user_mask_ptr: user-space pointer to the new cpu mask
5244 */
5245asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
5246 unsigned long __user *user_mask_ptr)
5247{
5248 cpumask_t new_mask;
5249 int retval;
5250
5251 retval = get_user_cpu_mask(user_mask_ptr, len, &new_mask);
5252 if (retval)
5253 return retval;
5254
Mike Travisb53e9212008-04-04 18:11:08 -07005255 return sched_setaffinity(pid, &new_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005256}
5257
Linus Torvalds1da177e2005-04-16 15:20:36 -07005258long sched_getaffinity(pid_t pid, cpumask_t *mask)
5259{
Ingo Molnar36c8b582006-07-03 00:25:41 -07005260 struct task_struct *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005261 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005262
Gautham R Shenoy95402b32008-01-25 21:08:02 +01005263 get_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005264 read_lock(&tasklist_lock);
5265
5266 retval = -ESRCH;
5267 p = find_process_by_pid(pid);
5268 if (!p)
5269 goto out_unlock;
5270
David Quigleye7834f82006-06-23 02:03:59 -07005271 retval = security_task_getscheduler(p);
5272 if (retval)
5273 goto out_unlock;
5274
Jack Steiner2f7016d2006-02-01 03:05:18 -08005275 cpus_and(*mask, p->cpus_allowed, cpu_online_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005276
5277out_unlock:
5278 read_unlock(&tasklist_lock);
Gautham R Shenoy95402b32008-01-25 21:08:02 +01005279 put_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005280
Ulrich Drepper9531b622007-08-09 11:16:46 +02005281 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005282}
5283
5284/**
5285 * sys_sched_getaffinity - get the cpu affinity of a process
5286 * @pid: pid of the process
5287 * @len: length in bytes of the bitmask pointed to by user_mask_ptr
5288 * @user_mask_ptr: user-space pointer to hold the current cpu mask
5289 */
5290asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
5291 unsigned long __user *user_mask_ptr)
5292{
5293 int ret;
5294 cpumask_t mask;
5295
5296 if (len < sizeof(cpumask_t))
5297 return -EINVAL;
5298
5299 ret = sched_getaffinity(pid, &mask);
5300 if (ret < 0)
5301 return ret;
5302
5303 if (copy_to_user(user_mask_ptr, &mask, sizeof(cpumask_t)))
5304 return -EFAULT;
5305
5306 return sizeof(cpumask_t);
5307}
5308
5309/**
5310 * sys_sched_yield - yield the current processor to other threads.
5311 *
Ingo Molnardd41f592007-07-09 18:51:59 +02005312 * This function yields the current CPU to other tasks. If there are no
5313 * other threads running on this CPU then this function will return.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005314 */
5315asmlinkage long sys_sched_yield(void)
5316{
Ingo Molnar70b97a72006-07-03 00:25:42 -07005317 struct rq *rq = this_rq_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005318
Ingo Molnar2d723762007-10-15 17:00:12 +02005319 schedstat_inc(rq, yld_count);
Dmitry Adamushko4530d7a2007-10-15 17:00:08 +02005320 current->sched_class->yield_task(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005321
5322 /*
5323 * Since we are going to call schedule() anyway, there's
5324 * no need to preempt or enable interrupts:
5325 */
5326 __release(rq->lock);
Ingo Molnar8a25d5d2006-07-03 00:24:54 -07005327 spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005328 _raw_spin_unlock(&rq->lock);
5329 preempt_enable_no_resched();
5330
5331 schedule();
5332
5333 return 0;
5334}
5335
Andrew Mortone7b38402006-06-30 01:56:00 -07005336static void __cond_resched(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005337{
Ingo Molnar8e0a43d2006-06-23 02:05:23 -07005338#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
5339 __might_sleep(__FILE__, __LINE__);
5340#endif
Ingo Molnar5bbcfd92005-07-07 17:57:04 -07005341 /*
5342 * The BKS might be reacquired before we have dropped
5343 * PREEMPT_ACTIVE, which could trigger a second
5344 * cond_resched() call.
5345 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07005346 do {
5347 add_preempt_count(PREEMPT_ACTIVE);
5348 schedule();
5349 sub_preempt_count(PREEMPT_ACTIVE);
5350 } while (need_resched());
5351}
5352
Herbert Xu02b67cc32008-01-25 21:08:28 +01005353int __sched _cond_resched(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005354{
Ingo Molnar94142322006-12-29 16:48:13 -08005355 if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) &&
5356 system_state == SYSTEM_RUNNING) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005357 __cond_resched();
5358 return 1;
5359 }
5360 return 0;
5361}
Herbert Xu02b67cc32008-01-25 21:08:28 +01005362EXPORT_SYMBOL(_cond_resched);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005363
5364/*
5365 * cond_resched_lock() - if a reschedule is pending, drop the given lock,
5366 * call schedule, and on return reacquire the lock.
5367 *
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005368 * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
Linus Torvalds1da177e2005-04-16 15:20:36 -07005369 * operations here to prevent schedule() from being called twice (once via
5370 * spin_unlock(), once by hand).
5371 */
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07005372int cond_resched_lock(spinlock_t *lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005373{
Nick Piggin95c354f2008-01-30 13:31:20 +01005374 int resched = need_resched() && system_state == SYSTEM_RUNNING;
Jan Kara6df3cec2005-06-13 15:52:32 -07005375 int ret = 0;
5376
Nick Piggin95c354f2008-01-30 13:31:20 +01005377 if (spin_needbreak(lock) || resched) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005378 spin_unlock(lock);
Nick Piggin95c354f2008-01-30 13:31:20 +01005379 if (resched && need_resched())
5380 __cond_resched();
5381 else
5382 cpu_relax();
Jan Kara6df3cec2005-06-13 15:52:32 -07005383 ret = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005384 spin_lock(lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005385 }
Jan Kara6df3cec2005-06-13 15:52:32 -07005386 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005387}
Linus Torvalds1da177e2005-04-16 15:20:36 -07005388EXPORT_SYMBOL(cond_resched_lock);
5389
5390int __sched cond_resched_softirq(void)
5391{
5392 BUG_ON(!in_softirq());
5393
Ingo Molnar94142322006-12-29 16:48:13 -08005394 if (need_resched() && system_state == SYSTEM_RUNNING) {
Thomas Gleixner98d825672007-05-23 13:58:18 -07005395 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005396 __cond_resched();
5397 local_bh_disable();
5398 return 1;
5399 }
5400 return 0;
5401}
Linus Torvalds1da177e2005-04-16 15:20:36 -07005402EXPORT_SYMBOL(cond_resched_softirq);
5403
Linus Torvalds1da177e2005-04-16 15:20:36 -07005404/**
5405 * yield - yield the current processor to other threads.
5406 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08005407 * This is a shortcut for kernel-space yielding - it marks the
Linus Torvalds1da177e2005-04-16 15:20:36 -07005408 * thread runnable and calls sys_sched_yield().
5409 */
5410void __sched yield(void)
5411{
5412 set_current_state(TASK_RUNNING);
5413 sys_sched_yield();
5414}
Linus Torvalds1da177e2005-04-16 15:20:36 -07005415EXPORT_SYMBOL(yield);
5416
5417/*
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005418 * This task is about to go to sleep on IO. Increment rq->nr_iowait so
Linus Torvalds1da177e2005-04-16 15:20:36 -07005419 * that process accounting knows that this is a task in IO wait state.
5420 *
5421 * But don't do that if it is a deliberate, throttling IO wait (this task
5422 * has set its backing_dev_info: the queue against which it should throttle)
5423 */
5424void __sched io_schedule(void)
5425{
Ingo Molnar70b97a72006-07-03 00:25:42 -07005426 struct rq *rq = &__raw_get_cpu_var(runqueues);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005427
Shailabh Nagar0ff92242006-07-14 00:24:37 -07005428 delayacct_blkio_start();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005429 atomic_inc(&rq->nr_iowait);
5430 schedule();
5431 atomic_dec(&rq->nr_iowait);
Shailabh Nagar0ff92242006-07-14 00:24:37 -07005432 delayacct_blkio_end();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005433}
Linus Torvalds1da177e2005-04-16 15:20:36 -07005434EXPORT_SYMBOL(io_schedule);
5435
5436long __sched io_schedule_timeout(long timeout)
5437{
Ingo Molnar70b97a72006-07-03 00:25:42 -07005438 struct rq *rq = &__raw_get_cpu_var(runqueues);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005439 long ret;
5440
Shailabh Nagar0ff92242006-07-14 00:24:37 -07005441 delayacct_blkio_start();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005442 atomic_inc(&rq->nr_iowait);
5443 ret = schedule_timeout(timeout);
5444 atomic_dec(&rq->nr_iowait);
Shailabh Nagar0ff92242006-07-14 00:24:37 -07005445 delayacct_blkio_end();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005446 return ret;
5447}
5448
5449/**
5450 * sys_sched_get_priority_max - return maximum RT priority.
5451 * @policy: scheduling class.
5452 *
5453 * this syscall returns the maximum rt_priority that can be used
5454 * by a given scheduling class.
5455 */
5456asmlinkage long sys_sched_get_priority_max(int policy)
5457{
5458 int ret = -EINVAL;
5459
5460 switch (policy) {
5461 case SCHED_FIFO:
5462 case SCHED_RR:
5463 ret = MAX_USER_RT_PRIO-1;
5464 break;
5465 case SCHED_NORMAL:
Ingo Molnarb0a94992006-01-14 13:20:41 -08005466 case SCHED_BATCH:
Ingo Molnardd41f592007-07-09 18:51:59 +02005467 case SCHED_IDLE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005468 ret = 0;
5469 break;
5470 }
5471 return ret;
5472}
5473
5474/**
5475 * sys_sched_get_priority_min - return minimum RT priority.
5476 * @policy: scheduling class.
5477 *
5478 * this syscall returns the minimum rt_priority that can be used
5479 * by a given scheduling class.
5480 */
5481asmlinkage long sys_sched_get_priority_min(int policy)
5482{
5483 int ret = -EINVAL;
5484
5485 switch (policy) {
5486 case SCHED_FIFO:
5487 case SCHED_RR:
5488 ret = 1;
5489 break;
5490 case SCHED_NORMAL:
Ingo Molnarb0a94992006-01-14 13:20:41 -08005491 case SCHED_BATCH:
Ingo Molnardd41f592007-07-09 18:51:59 +02005492 case SCHED_IDLE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005493 ret = 0;
5494 }
5495 return ret;
5496}
5497
5498/**
5499 * sys_sched_rr_get_interval - return the default timeslice of a process.
5500 * @pid: pid of the process.
5501 * @interval: userspace pointer to the timeslice value.
5502 *
5503 * this syscall writes the default timeslice value of a given process
5504 * into the user-space timespec buffer. A value of '0' means infinity.
5505 */
5506asmlinkage
5507long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
5508{
Ingo Molnar36c8b582006-07-03 00:25:41 -07005509 struct task_struct *p;
Dmitry Adamushkoa4ec24b2007-10-15 17:00:13 +02005510 unsigned int time_slice;
Andi Kleen3a5c3592007-10-15 17:00:14 +02005511 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005512 struct timespec t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005513
5514 if (pid < 0)
Andi Kleen3a5c3592007-10-15 17:00:14 +02005515 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005516
5517 retval = -ESRCH;
5518 read_lock(&tasklist_lock);
5519 p = find_process_by_pid(pid);
5520 if (!p)
5521 goto out_unlock;
5522
5523 retval = security_task_getscheduler(p);
5524 if (retval)
5525 goto out_unlock;
5526
Ingo Molnar77034932007-12-04 17:04:39 +01005527 /*
5528 * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
5529 * tasks that are on an otherwise idle runqueue:
5530 */
5531 time_slice = 0;
5532 if (p->policy == SCHED_RR) {
Dmitry Adamushkoa4ec24b2007-10-15 17:00:13 +02005533 time_slice = DEF_TIMESLICE;
Miao Xie1868f952008-03-07 09:35:06 +08005534 } else if (p->policy != SCHED_FIFO) {
Dmitry Adamushkoa4ec24b2007-10-15 17:00:13 +02005535 struct sched_entity *se = &p->se;
5536 unsigned long flags;
5537 struct rq *rq;
5538
5539 rq = task_rq_lock(p, &flags);
Ingo Molnar77034932007-12-04 17:04:39 +01005540 if (rq->cfs.load.weight)
5541 time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
Dmitry Adamushkoa4ec24b2007-10-15 17:00:13 +02005542 task_rq_unlock(rq, &flags);
5543 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005544 read_unlock(&tasklist_lock);
Dmitry Adamushkoa4ec24b2007-10-15 17:00:13 +02005545 jiffies_to_timespec(time_slice, &t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005546 retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005547 return retval;
Andi Kleen3a5c3592007-10-15 17:00:14 +02005548
Linus Torvalds1da177e2005-04-16 15:20:36 -07005549out_unlock:
5550 read_unlock(&tasklist_lock);
5551 return retval;
5552}
5553
Andreas Mohr2ed6e342006-07-10 04:43:52 -07005554static const char stat_nam[] = "RSDTtZX";
Ingo Molnar36c8b582006-07-03 00:25:41 -07005555
Ingo Molnar82a1fcb2008-01-25 21:08:02 +01005556void sched_show_task(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005557{
Linus Torvalds1da177e2005-04-16 15:20:36 -07005558 unsigned long free = 0;
Ingo Molnar36c8b582006-07-03 00:25:41 -07005559 unsigned state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005560
Linus Torvalds1da177e2005-04-16 15:20:36 -07005561 state = p->state ? __ffs(p->state) + 1 : 0;
Ingo Molnarcc4ea792007-10-18 21:32:56 +02005562 printk(KERN_INFO "%-13.13s %c", p->comm,
Andreas Mohr2ed6e342006-07-10 04:43:52 -07005563 state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
Ingo Molnar4bd77322007-07-11 21:21:47 +02005564#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -07005565 if (state == TASK_RUNNING)
Ingo Molnarcc4ea792007-10-18 21:32:56 +02005566 printk(KERN_CONT " running ");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005567 else
Ingo Molnarcc4ea792007-10-18 21:32:56 +02005568 printk(KERN_CONT " %08lx ", thread_saved_pc(p));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005569#else
5570 if (state == TASK_RUNNING)
Ingo Molnarcc4ea792007-10-18 21:32:56 +02005571 printk(KERN_CONT " running task ");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005572 else
Ingo Molnarcc4ea792007-10-18 21:32:56 +02005573 printk(KERN_CONT " %016lx ", thread_saved_pc(p));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005574#endif
5575#ifdef CONFIG_DEBUG_STACK_USAGE
5576 {
Al Viro10ebffd2005-11-13 16:06:56 -08005577 unsigned long *n = end_of_stack(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005578 while (!*n)
5579 n++;
Al Viro10ebffd2005-11-13 16:06:56 -08005580 free = (unsigned long)n - (unsigned long)end_of_stack(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005581 }
5582#endif
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -07005583 printk(KERN_CONT "%5lu %5d %6d\n", free,
Roland McGrathfcfd50a2008-01-09 00:03:23 -08005584 task_pid_nr(p), task_pid_nr(p->real_parent));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005585
Nick Piggin5fb5e6d2008-01-25 21:08:34 +01005586 show_stack(p, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005587}
5588
Ingo Molnare59e2ae2006-12-06 20:35:59 -08005589void show_state_filter(unsigned long state_filter)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005590{
Ingo Molnar36c8b582006-07-03 00:25:41 -07005591 struct task_struct *g, *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005592
Ingo Molnar4bd77322007-07-11 21:21:47 +02005593#if BITS_PER_LONG == 32
5594 printk(KERN_INFO
5595 " task PC stack pid father\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005596#else
Ingo Molnar4bd77322007-07-11 21:21:47 +02005597 printk(KERN_INFO
5598 " task PC stack pid father\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07005599#endif
5600 read_lock(&tasklist_lock);
5601 do_each_thread(g, p) {
5602 /*
5603 * reset the NMI-timeout, listing all files on a slow
5604 * console might take alot of time:
5605 */
5606 touch_nmi_watchdog();
Ingo Molnar39bc89f2007-04-25 20:50:03 -07005607 if (!state_filter || (p->state & state_filter))
Ingo Molnar82a1fcb2008-01-25 21:08:02 +01005608 sched_show_task(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005609 } while_each_thread(g, p);
5610
Jeremy Fitzhardinge04c91672007-05-08 00:28:05 -07005611 touch_all_softlockup_watchdogs();
5612
Ingo Molnardd41f592007-07-09 18:51:59 +02005613#ifdef CONFIG_SCHED_DEBUG
5614 sysrq_sched_debug_show();
5615#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07005616 read_unlock(&tasklist_lock);
Ingo Molnare59e2ae2006-12-06 20:35:59 -08005617 /*
5618 * Only show locks if all tasks are dumped:
5619 */
5620 if (state_filter == -1)
5621 debug_show_all_locks();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005622}
5623
Ingo Molnar1df21052007-07-09 18:51:58 +02005624void __cpuinit init_idle_bootup_task(struct task_struct *idle)
5625{
Ingo Molnardd41f592007-07-09 18:51:59 +02005626 idle->sched_class = &idle_sched_class;
Ingo Molnar1df21052007-07-09 18:51:58 +02005627}
5628
Ingo Molnarf340c0d2005-06-28 16:40:42 +02005629/**
5630 * init_idle - set up an idle thread for a given CPU
5631 * @idle: task in question
5632 * @cpu: cpu the idle task belongs to
5633 *
5634 * NOTE: this function does not set the idle thread's NEED_RESCHED
5635 * flag, to make booting more robust.
5636 */
Nick Piggin5c1e1762006-10-03 01:14:04 -07005637void __cpuinit init_idle(struct task_struct *idle, int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005638{
Ingo Molnar70b97a72006-07-03 00:25:42 -07005639 struct rq *rq = cpu_rq(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005640 unsigned long flags;
5641
Ingo Molnardd41f592007-07-09 18:51:59 +02005642 __sched_fork(idle);
5643 idle->se.exec_start = sched_clock();
5644
Ingo Molnarb29739f2006-06-27 02:54:51 -07005645 idle->prio = idle->normal_prio = MAX_PRIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005646 idle->cpus_allowed = cpumask_of_cpu(cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02005647 __set_task_cpu(idle, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005648
5649 spin_lock_irqsave(&rq->lock, flags);
5650 rq->curr = rq->idle = idle;
Nick Piggin4866cde2005-06-25 14:57:23 -07005651#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
5652 idle->oncpu = 1;
5653#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07005654 spin_unlock_irqrestore(&rq->lock, flags);
5655
5656 /* Set the preempt count _outside_ the spinlocks! */
Linus Torvalds8e3e0762008-05-10 20:58:02 -07005657#if defined(CONFIG_PREEMPT)
5658 task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
5659#else
Al Viroa1261f52005-11-13 16:06:55 -08005660 task_thread_info(idle)->preempt_count = 0;
Linus Torvalds8e3e0762008-05-10 20:58:02 -07005661#endif
Ingo Molnardd41f592007-07-09 18:51:59 +02005662 /*
5663 * The idle tasks have their own, simple scheduling class:
5664 */
5665 idle->sched_class = &idle_sched_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005666}
5667
5668/*
5669 * In a system that switches off the HZ timer nohz_cpu_mask
5670 * indicates which cpus entered this state. This is used
5671 * in the rcu update to wait only for active cpus. For system
5672 * which do not switch off the HZ timer nohz_cpu_mask should
5673 * always be CPU_MASK_NONE.
5674 */
5675cpumask_t nohz_cpu_mask = CPU_MASK_NONE;
5676
Ingo Molnar19978ca2007-11-09 22:39:38 +01005677/*
5678 * Increase the granularity value when there are more CPUs,
5679 * because with more CPUs the 'effective latency' as visible
5680 * to users decreases. But the relationship is not linear,
5681 * so pick a second-best guess by going with the log2 of the
5682 * number of CPUs.
5683 *
5684 * This idea comes from the SD scheduler of Con Kolivas:
5685 */
5686static inline void sched_init_granularity(void)
5687{
5688 unsigned int factor = 1 + ilog2(num_online_cpus());
5689 const unsigned long limit = 200000000;
5690
5691 sysctl_sched_min_granularity *= factor;
5692 if (sysctl_sched_min_granularity > limit)
5693 sysctl_sched_min_granularity = limit;
5694
5695 sysctl_sched_latency *= factor;
5696 if (sysctl_sched_latency > limit)
5697 sysctl_sched_latency = limit;
5698
5699 sysctl_sched_wakeup_granularity *= factor;
Ingo Molnar19978ca2007-11-09 22:39:38 +01005700}
5701
Linus Torvalds1da177e2005-04-16 15:20:36 -07005702#ifdef CONFIG_SMP
5703/*
5704 * This is how migration works:
5705 *
Ingo Molnar70b97a72006-07-03 00:25:42 -07005706 * 1) we queue a struct migration_req structure in the source CPU's
Linus Torvalds1da177e2005-04-16 15:20:36 -07005707 * runqueue and wake up that CPU's migration thread.
5708 * 2) we down() the locked semaphore => thread blocks.
5709 * 3) migration thread wakes up (implicitly it forces the migrated
5710 * thread off the CPU)
5711 * 4) it gets the migration request and checks whether the migrated
5712 * task is still in the wrong runqueue.
5713 * 5) if it's in the wrong runqueue then the migration thread removes
5714 * it and puts it into the right queue.
5715 * 6) migration thread up()s the semaphore.
5716 * 7) we wake up and the migration is done.
5717 */
5718
5719/*
5720 * Change a given task's CPU affinity. Migrate the thread to a
5721 * proper CPU and schedule it away if the CPU it's executing on
5722 * is removed from the allowed bitmask.
5723 *
5724 * NOTE: the caller must have a valid reference to the task, the
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005725 * task must not exit() & deallocate itself prematurely. The
Linus Torvalds1da177e2005-04-16 15:20:36 -07005726 * call is not atomic; no spinlocks may be held.
5727 */
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005728int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005729{
Ingo Molnar70b97a72006-07-03 00:25:42 -07005730 struct migration_req req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005731 unsigned long flags;
Ingo Molnar70b97a72006-07-03 00:25:42 -07005732 struct rq *rq;
Ingo Molnar48f24c42006-07-03 00:25:40 -07005733 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005734
5735 rq = task_rq_lock(p, &flags);
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005736 if (!cpus_intersects(*new_mask, cpu_online_map)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005737 ret = -EINVAL;
5738 goto out;
5739 }
5740
David Rientjes9985b0b2008-06-05 12:57:11 -07005741 if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
5742 !cpus_equal(p->cpus_allowed, *new_mask))) {
5743 ret = -EINVAL;
5744 goto out;
5745 }
5746
Gregory Haskins73fe6aa2008-01-25 21:08:07 +01005747 if (p->sched_class->set_cpus_allowed)
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005748 p->sched_class->set_cpus_allowed(p, new_mask);
Gregory Haskins73fe6aa2008-01-25 21:08:07 +01005749 else {
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005750 p->cpus_allowed = *new_mask;
5751 p->rt.nr_cpus_allowed = cpus_weight(*new_mask);
Gregory Haskins73fe6aa2008-01-25 21:08:07 +01005752 }
5753
Linus Torvalds1da177e2005-04-16 15:20:36 -07005754 /* Can the task run on the task's current CPU? If so, we're done */
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005755 if (cpu_isset(task_cpu(p), *new_mask))
Linus Torvalds1da177e2005-04-16 15:20:36 -07005756 goto out;
5757
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005758 if (migrate_task(p, any_online_cpu(*new_mask), &req)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005759 /* Need help from migration thread: drop lock and wait. */
5760 task_rq_unlock(rq, &flags);
5761 wake_up_process(rq->migration_thread);
5762 wait_for_completion(&req.done);
5763 tlb_migrate_finish(p->mm);
5764 return 0;
5765 }
5766out:
5767 task_rq_unlock(rq, &flags);
Ingo Molnar48f24c42006-07-03 00:25:40 -07005768
Linus Torvalds1da177e2005-04-16 15:20:36 -07005769 return ret;
5770}
Mike Traviscd8ba7c2008-03-26 14:23:49 -07005771EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005772
5773/*
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005774 * Move (not current) task off this cpu, onto dest cpu. We're doing
Linus Torvalds1da177e2005-04-16 15:20:36 -07005775 * this because either it can't run here any more (set_cpus_allowed()
5776 * away from this CPU, or CPU going down), or because we're
5777 * attempting to rebalance this task on exec (sched_exec).
5778 *
5779 * So we race with normal scheduler movements, but that's OK, as long
5780 * as the task is no longer on this CPU.
Kirill Korotaevefc30812006-06-27 02:54:32 -07005781 *
5782 * Returns non-zero if task was successfully migrated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005783 */
Kirill Korotaevefc30812006-06-27 02:54:32 -07005784static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005785{
Ingo Molnar70b97a72006-07-03 00:25:42 -07005786 struct rq *rq_dest, *rq_src;
Ingo Molnardd41f592007-07-09 18:51:59 +02005787 int ret = 0, on_rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005788
5789 if (unlikely(cpu_is_offline(dest_cpu)))
Kirill Korotaevefc30812006-06-27 02:54:32 -07005790 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005791
5792 rq_src = cpu_rq(src_cpu);
5793 rq_dest = cpu_rq(dest_cpu);
5794
5795 double_rq_lock(rq_src, rq_dest);
5796 /* Already moved. */
5797 if (task_cpu(p) != src_cpu)
5798 goto out;
5799 /* Affinity changed (again). */
5800 if (!cpu_isset(dest_cpu, p->cpus_allowed))
5801 goto out;
5802
Ingo Molnardd41f592007-07-09 18:51:59 +02005803 on_rq = p->se.on_rq;
Ingo Molnar6e82a3b2007-08-09 11:16:51 +02005804 if (on_rq)
Ingo Molnar2e1cb742007-08-09 11:16:49 +02005805 deactivate_task(rq_src, p, 0);
Ingo Molnar6e82a3b2007-08-09 11:16:51 +02005806
Linus Torvalds1da177e2005-04-16 15:20:36 -07005807 set_task_cpu(p, dest_cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02005808 if (on_rq) {
5809 activate_task(rq_dest, p, 0);
5810 check_preempt_curr(rq_dest, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005811 }
Kirill Korotaevefc30812006-06-27 02:54:32 -07005812 ret = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005813out:
5814 double_rq_unlock(rq_src, rq_dest);
Kirill Korotaevefc30812006-06-27 02:54:32 -07005815 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005816}
5817
5818/*
5819 * migration_thread - this is a highprio system thread that performs
5820 * thread migration by bumping thread off CPU then 'pushing' onto
5821 * another runqueue.
5822 */
Ingo Molnar95cdf3b2005-09-10 00:26:11 -07005823static int migration_thread(void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005824{
Linus Torvalds1da177e2005-04-16 15:20:36 -07005825 int cpu = (long)data;
Ingo Molnar70b97a72006-07-03 00:25:42 -07005826 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005827
5828 rq = cpu_rq(cpu);
5829 BUG_ON(rq->migration_thread != current);
5830
5831 set_current_state(TASK_INTERRUPTIBLE);
5832 while (!kthread_should_stop()) {
Ingo Molnar70b97a72006-07-03 00:25:42 -07005833 struct migration_req *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005834 struct list_head *head;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005835
Linus Torvalds1da177e2005-04-16 15:20:36 -07005836 spin_lock_irq(&rq->lock);
5837
5838 if (cpu_is_offline(cpu)) {
5839 spin_unlock_irq(&rq->lock);
5840 goto wait_to_die;
5841 }
5842
5843 if (rq->active_balance) {
5844 active_load_balance(rq, cpu);
5845 rq->active_balance = 0;
5846 }
5847
5848 head = &rq->migration_queue;
5849
5850 if (list_empty(head)) {
5851 spin_unlock_irq(&rq->lock);
5852 schedule();
5853 set_current_state(TASK_INTERRUPTIBLE);
5854 continue;
5855 }
Ingo Molnar70b97a72006-07-03 00:25:42 -07005856 req = list_entry(head->next, struct migration_req, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005857 list_del_init(head->next);
5858
Nick Piggin674311d2005-06-25 14:57:27 -07005859 spin_unlock(&rq->lock);
5860 __migrate_task(req->task, cpu, req->dest_cpu);
5861 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -07005862
5863 complete(&req->done);
5864 }
5865 __set_current_state(TASK_RUNNING);
5866 return 0;
5867
5868wait_to_die:
5869 /* Wait for kthread_stop */
5870 set_current_state(TASK_INTERRUPTIBLE);
5871 while (!kthread_should_stop()) {
5872 schedule();
5873 set_current_state(TASK_INTERRUPTIBLE);
5874 }
5875 __set_current_state(TASK_RUNNING);
5876 return 0;
5877}
5878
5879#ifdef CONFIG_HOTPLUG_CPU
Oleg Nesterovf7b4cdd2007-10-16 23:30:56 -07005880
5881static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
5882{
5883 int ret;
5884
5885 local_irq_disable();
5886 ret = __migrate_task(p, src_cpu, dest_cpu);
5887 local_irq_enable();
5888 return ret;
5889}
5890
Kirill Korotaev054b9102006-12-10 02:20:11 -08005891/*
Robert P. J. Day3a4fa0a2007-10-19 23:10:43 +02005892 * Figure out where task on dead CPU should go, use force if necessary.
Kirill Korotaev054b9102006-12-10 02:20:11 -08005893 * NOTE: interrupts should be disabled by the caller
5894 */
Ingo Molnar48f24c42006-07-03 00:25:40 -07005895static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005896{
Kirill Korotaevefc30812006-06-27 02:54:32 -07005897 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005898 cpumask_t mask;
Ingo Molnar70b97a72006-07-03 00:25:42 -07005899 struct rq *rq;
5900 int dest_cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005901
Andi Kleen3a5c3592007-10-15 17:00:14 +02005902 do {
5903 /* On same node? */
5904 mask = node_to_cpumask(cpu_to_node(dead_cpu));
5905 cpus_and(mask, mask, p->cpus_allowed);
5906 dest_cpu = any_online_cpu(mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005907
Andi Kleen3a5c3592007-10-15 17:00:14 +02005908 /* On any allowed CPU? */
Mike Travis434d53b2008-04-04 18:11:04 -07005909 if (dest_cpu >= nr_cpu_ids)
Andi Kleen3a5c3592007-10-15 17:00:14 +02005910 dest_cpu = any_online_cpu(p->cpus_allowed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005911
Andi Kleen3a5c3592007-10-15 17:00:14 +02005912 /* No more Mr. Nice Guy. */
Mike Travis434d53b2008-04-04 18:11:04 -07005913 if (dest_cpu >= nr_cpu_ids) {
Mike Travisf9a86fc2008-04-04 18:11:07 -07005914 cpumask_t cpus_allowed;
5915
5916 cpuset_cpus_allowed_locked(p, &cpus_allowed);
Cliff Wickman470fd642007-10-18 23:40:46 -07005917 /*
5918 * Try to stay on the same cpuset, where the
5919 * current cpuset may be a subset of all cpus.
5920 * The cpuset_cpus_allowed_locked() variant of
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005921 * cpuset_cpus_allowed() will not block. It must be
Cliff Wickman470fd642007-10-18 23:40:46 -07005922 * called within calls to cpuset_lock/cpuset_unlock.
5923 */
Andi Kleen3a5c3592007-10-15 17:00:14 +02005924 rq = task_rq_lock(p, &flags);
Cliff Wickman470fd642007-10-18 23:40:46 -07005925 p->cpus_allowed = cpus_allowed;
Andi Kleen3a5c3592007-10-15 17:00:14 +02005926 dest_cpu = any_online_cpu(p->cpus_allowed);
5927 task_rq_unlock(rq, &flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005928
Andi Kleen3a5c3592007-10-15 17:00:14 +02005929 /*
5930 * Don't tell them about moving exiting tasks or
5931 * kernel threads (both mm NULL), since they never
5932 * leave kernel.
5933 */
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005934 if (p->mm && printk_ratelimit()) {
Andi Kleen3a5c3592007-10-15 17:00:14 +02005935 printk(KERN_INFO "process %d (%s) no "
5936 "longer affine to cpu%d\n",
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01005937 task_pid_nr(p), p->comm, dead_cpu);
5938 }
Andi Kleen3a5c3592007-10-15 17:00:14 +02005939 }
Oleg Nesterovf7b4cdd2007-10-16 23:30:56 -07005940 } while (!__migrate_task_irq(p, dead_cpu, dest_cpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005941}
5942
5943/*
5944 * While a dead CPU has no uninterruptible tasks queued at this point,
5945 * it might still have a nonzero ->nr_uninterruptible counter, because
5946 * for performance reasons the counter is not stricly tracking tasks to
5947 * their home CPUs. So we just add the counter to another CPU's counter,
5948 * to keep the global sum constant after CPU-down:
5949 */
Ingo Molnar70b97a72006-07-03 00:25:42 -07005950static void migrate_nr_uninterruptible(struct rq *rq_src)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005951{
Mike Travis7c16ec52008-04-04 18:11:11 -07005952 struct rq *rq_dest = cpu_rq(any_online_cpu(*CPU_MASK_ALL_PTR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005953 unsigned long flags;
5954
5955 local_irq_save(flags);
5956 double_rq_lock(rq_src, rq_dest);
5957 rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible;
5958 rq_src->nr_uninterruptible = 0;
5959 double_rq_unlock(rq_src, rq_dest);
5960 local_irq_restore(flags);
5961}
5962
5963/* Run through task list and migrate tasks from the dead cpu. */
5964static void migrate_live_tasks(int src_cpu)
5965{
Ingo Molnar48f24c42006-07-03 00:25:40 -07005966 struct task_struct *p, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005967
Oleg Nesterovf7b4cdd2007-10-16 23:30:56 -07005968 read_lock(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005969
Ingo Molnar48f24c42006-07-03 00:25:40 -07005970 do_each_thread(t, p) {
5971 if (p == current)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005972 continue;
5973
Ingo Molnar48f24c42006-07-03 00:25:40 -07005974 if (task_cpu(p) == src_cpu)
5975 move_task_off_dead_cpu(src_cpu, p);
5976 } while_each_thread(t, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005977
Oleg Nesterovf7b4cdd2007-10-16 23:30:56 -07005978 read_unlock(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005979}
5980
Ingo Molnardd41f592007-07-09 18:51:59 +02005981/*
5982 * Schedules idle task to be the next runnable task on current CPU.
Dmitry Adamushko94bc9a72007-11-15 20:57:40 +01005983 * It does so by boosting its priority to highest possible.
5984 * Used by CPU offline code.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005985 */
5986void sched_idle_next(void)
5987{
Ingo Molnar48f24c42006-07-03 00:25:40 -07005988 int this_cpu = smp_processor_id();
Ingo Molnar70b97a72006-07-03 00:25:42 -07005989 struct rq *rq = cpu_rq(this_cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005990 struct task_struct *p = rq->idle;
5991 unsigned long flags;
5992
5993 /* cpu has to be offline */
Ingo Molnar48f24c42006-07-03 00:25:40 -07005994 BUG_ON(cpu_online(this_cpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005995
Ingo Molnar48f24c42006-07-03 00:25:40 -07005996 /*
5997 * Strictly not necessary since rest of the CPUs are stopped by now
5998 * and interrupts disabled on the current cpu.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005999 */
6000 spin_lock_irqsave(&rq->lock, flags);
6001
Ingo Molnardd41f592007-07-09 18:51:59 +02006002 __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
Ingo Molnar48f24c42006-07-03 00:25:40 -07006003
Dmitry Adamushko94bc9a72007-11-15 20:57:40 +01006004 update_rq_clock(rq);
6005 activate_task(rq, p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006006
6007 spin_unlock_irqrestore(&rq->lock, flags);
6008}
6009
Ingo Molnar48f24c42006-07-03 00:25:40 -07006010/*
6011 * Ensures that the idle task is using init_mm right before its cpu goes
Linus Torvalds1da177e2005-04-16 15:20:36 -07006012 * offline.
6013 */
6014void idle_task_exit(void)
6015{
6016 struct mm_struct *mm = current->active_mm;
6017
6018 BUG_ON(cpu_online(smp_processor_id()));
6019
6020 if (mm != &init_mm)
6021 switch_mm(mm, &init_mm, current);
6022 mmdrop(mm);
6023}
6024
Kirill Korotaev054b9102006-12-10 02:20:11 -08006025/* called under rq->lock with disabled interrupts */
Ingo Molnar36c8b582006-07-03 00:25:41 -07006026static void migrate_dead(unsigned int dead_cpu, struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006027{
Ingo Molnar70b97a72006-07-03 00:25:42 -07006028 struct rq *rq = cpu_rq(dead_cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006029
6030 /* Must be exiting, otherwise would be on tasklist. */
Eugene Teo270f7222007-10-18 23:40:38 -07006031 BUG_ON(!p->exit_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006032
6033 /* Cannot have done final schedule yet: would have vanished. */
Oleg Nesterovc394cc92006-09-29 02:01:11 -07006034 BUG_ON(p->state == TASK_DEAD);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006035
Ingo Molnar48f24c42006-07-03 00:25:40 -07006036 get_task_struct(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006037
6038 /*
6039 * Drop lock around migration; if someone else moves it,
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006040 * that's OK. No task can be added to this CPU, so iteration is
Linus Torvalds1da177e2005-04-16 15:20:36 -07006041 * fine.
6042 */
Oleg Nesterovf7b4cdd2007-10-16 23:30:56 -07006043 spin_unlock_irq(&rq->lock);
Ingo Molnar48f24c42006-07-03 00:25:40 -07006044 move_task_off_dead_cpu(dead_cpu, p);
Oleg Nesterovf7b4cdd2007-10-16 23:30:56 -07006045 spin_lock_irq(&rq->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006046
Ingo Molnar48f24c42006-07-03 00:25:40 -07006047 put_task_struct(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006048}
6049
6050/* release_task() removes task from tasklist, so we won't find dead tasks. */
6051static void migrate_dead_tasks(unsigned int dead_cpu)
6052{
Ingo Molnar70b97a72006-07-03 00:25:42 -07006053 struct rq *rq = cpu_rq(dead_cpu);
Ingo Molnardd41f592007-07-09 18:51:59 +02006054 struct task_struct *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006055
Ingo Molnardd41f592007-07-09 18:51:59 +02006056 for ( ; ; ) {
6057 if (!rq->nr_running)
6058 break;
Ingo Molnara8e504d2007-08-09 11:16:47 +02006059 update_rq_clock(rq);
Ingo Molnarff95f3d2007-08-09 11:16:49 +02006060 next = pick_next_task(rq, rq->curr);
Ingo Molnardd41f592007-07-09 18:51:59 +02006061 if (!next)
6062 break;
6063 migrate_dead(dead_cpu, next);
Nick Piggine692ab52007-07-26 13:40:43 +02006064
Linus Torvalds1da177e2005-04-16 15:20:36 -07006065 }
6066}
6067#endif /* CONFIG_HOTPLUG_CPU */
6068
Nick Piggine692ab52007-07-26 13:40:43 +02006069#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
6070
6071static struct ctl_table sd_ctl_dir[] = {
Alexey Dobriyane0361852007-08-09 11:16:46 +02006072 {
6073 .procname = "sched_domain",
Eric W. Biedermanc57baf12007-08-23 15:18:02 +02006074 .mode = 0555,
Alexey Dobriyane0361852007-08-09 11:16:46 +02006075 },
Ingo Molnar38605ca2007-10-29 21:18:11 +01006076 {0, },
Nick Piggine692ab52007-07-26 13:40:43 +02006077};
6078
6079static struct ctl_table sd_ctl_root[] = {
Alexey Dobriyane0361852007-08-09 11:16:46 +02006080 {
Eric W. Biedermanc57baf12007-08-23 15:18:02 +02006081 .ctl_name = CTL_KERN,
Alexey Dobriyane0361852007-08-09 11:16:46 +02006082 .procname = "kernel",
Eric W. Biedermanc57baf12007-08-23 15:18:02 +02006083 .mode = 0555,
Alexey Dobriyane0361852007-08-09 11:16:46 +02006084 .child = sd_ctl_dir,
6085 },
Ingo Molnar38605ca2007-10-29 21:18:11 +01006086 {0, },
Nick Piggine692ab52007-07-26 13:40:43 +02006087};
6088
6089static struct ctl_table *sd_alloc_ctl_entry(int n)
6090{
6091 struct ctl_table *entry =
Milton Miller5cf9f062007-10-15 17:00:19 +02006092 kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
Nick Piggine692ab52007-07-26 13:40:43 +02006093
Nick Piggine692ab52007-07-26 13:40:43 +02006094 return entry;
6095}
6096
Milton Miller6382bc92007-10-15 17:00:19 +02006097static void sd_free_ctl_entry(struct ctl_table **tablep)
6098{
Milton Millercd790072007-10-17 16:55:11 +02006099 struct ctl_table *entry;
Milton Miller6382bc92007-10-15 17:00:19 +02006100
Milton Millercd790072007-10-17 16:55:11 +02006101 /*
6102 * In the intermediate directories, both the child directory and
6103 * procname are dynamically allocated and could fail but the mode
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006104 * will always be set. In the lowest directory the names are
Milton Millercd790072007-10-17 16:55:11 +02006105 * static strings and all have proc handlers.
6106 */
6107 for (entry = *tablep; entry->mode; entry++) {
Milton Miller6382bc92007-10-15 17:00:19 +02006108 if (entry->child)
6109 sd_free_ctl_entry(&entry->child);
Milton Millercd790072007-10-17 16:55:11 +02006110 if (entry->proc_handler == NULL)
6111 kfree(entry->procname);
6112 }
Milton Miller6382bc92007-10-15 17:00:19 +02006113
6114 kfree(*tablep);
6115 *tablep = NULL;
6116}
6117
Nick Piggine692ab52007-07-26 13:40:43 +02006118static void
Alexey Dobriyane0361852007-08-09 11:16:46 +02006119set_table_entry(struct ctl_table *entry,
Nick Piggine692ab52007-07-26 13:40:43 +02006120 const char *procname, void *data, int maxlen,
6121 mode_t mode, proc_handler *proc_handler)
6122{
Nick Piggine692ab52007-07-26 13:40:43 +02006123 entry->procname = procname;
6124 entry->data = data;
6125 entry->maxlen = maxlen;
6126 entry->mode = mode;
6127 entry->proc_handler = proc_handler;
6128}
6129
6130static struct ctl_table *
6131sd_alloc_ctl_domain_table(struct sched_domain *sd)
6132{
Zou Nan haiace8b3d2007-10-15 17:00:14 +02006133 struct ctl_table *table = sd_alloc_ctl_entry(12);
Nick Piggine692ab52007-07-26 13:40:43 +02006134
Milton Millerad1cdc12007-10-15 17:00:19 +02006135 if (table == NULL)
6136 return NULL;
6137
Alexey Dobriyane0361852007-08-09 11:16:46 +02006138 set_table_entry(&table[0], "min_interval", &sd->min_interval,
Nick Piggine692ab52007-07-26 13:40:43 +02006139 sizeof(long), 0644, proc_doulongvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006140 set_table_entry(&table[1], "max_interval", &sd->max_interval,
Nick Piggine692ab52007-07-26 13:40:43 +02006141 sizeof(long), 0644, proc_doulongvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006142 set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
Nick Piggine692ab52007-07-26 13:40:43 +02006143 sizeof(int), 0644, proc_dointvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006144 set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
Nick Piggine692ab52007-07-26 13:40:43 +02006145 sizeof(int), 0644, proc_dointvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006146 set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
Nick Piggine692ab52007-07-26 13:40:43 +02006147 sizeof(int), 0644, proc_dointvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006148 set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
Nick Piggine692ab52007-07-26 13:40:43 +02006149 sizeof(int), 0644, proc_dointvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006150 set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
Nick Piggine692ab52007-07-26 13:40:43 +02006151 sizeof(int), 0644, proc_dointvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006152 set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
Nick Piggine692ab52007-07-26 13:40:43 +02006153 sizeof(int), 0644, proc_dointvec_minmax);
Alexey Dobriyane0361852007-08-09 11:16:46 +02006154 set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
Nick Piggine692ab52007-07-26 13:40:43 +02006155 sizeof(int), 0644, proc_dointvec_minmax);
Zou Nan haiace8b3d2007-10-15 17:00:14 +02006156 set_table_entry(&table[9], "cache_nice_tries",
Nick Piggine692ab52007-07-26 13:40:43 +02006157 &sd->cache_nice_tries,
6158 sizeof(int), 0644, proc_dointvec_minmax);
Zou Nan haiace8b3d2007-10-15 17:00:14 +02006159 set_table_entry(&table[10], "flags", &sd->flags,
Nick Piggine692ab52007-07-26 13:40:43 +02006160 sizeof(int), 0644, proc_dointvec_minmax);
Milton Miller6323469f2007-10-15 17:00:19 +02006161 /* &table[11] is terminator */
Nick Piggine692ab52007-07-26 13:40:43 +02006162
6163 return table;
6164}
6165
Ingo Molnar9a4e7152007-11-28 15:52:56 +01006166static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
Nick Piggine692ab52007-07-26 13:40:43 +02006167{
6168 struct ctl_table *entry, *table;
6169 struct sched_domain *sd;
6170 int domain_num = 0, i;
6171 char buf[32];
6172
6173 for_each_domain(cpu, sd)
6174 domain_num++;
6175 entry = table = sd_alloc_ctl_entry(domain_num + 1);
Milton Millerad1cdc12007-10-15 17:00:19 +02006176 if (table == NULL)
6177 return NULL;
Nick Piggine692ab52007-07-26 13:40:43 +02006178
6179 i = 0;
6180 for_each_domain(cpu, sd) {
6181 snprintf(buf, 32, "domain%d", i);
Nick Piggine692ab52007-07-26 13:40:43 +02006182 entry->procname = kstrdup(buf, GFP_KERNEL);
Eric W. Biedermanc57baf12007-08-23 15:18:02 +02006183 entry->mode = 0555;
Nick Piggine692ab52007-07-26 13:40:43 +02006184 entry->child = sd_alloc_ctl_domain_table(sd);
6185 entry++;
6186 i++;
6187 }
6188 return table;
6189}
6190
6191static struct ctl_table_header *sd_sysctl_header;
Milton Miller6382bc92007-10-15 17:00:19 +02006192static void register_sched_domain_sysctl(void)
Nick Piggine692ab52007-07-26 13:40:43 +02006193{
6194 int i, cpu_num = num_online_cpus();
6195 struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
6196 char buf[32];
6197
Milton Miller73785472007-10-24 18:23:48 +02006198 WARN_ON(sd_ctl_dir[0].child);
6199 sd_ctl_dir[0].child = entry;
6200
Milton Millerad1cdc12007-10-15 17:00:19 +02006201 if (entry == NULL)
6202 return;
6203
Milton Miller97b6ea72007-10-15 17:00:19 +02006204 for_each_online_cpu(i) {
Nick Piggine692ab52007-07-26 13:40:43 +02006205 snprintf(buf, 32, "cpu%d", i);
Nick Piggine692ab52007-07-26 13:40:43 +02006206 entry->procname = kstrdup(buf, GFP_KERNEL);
Eric W. Biedermanc57baf12007-08-23 15:18:02 +02006207 entry->mode = 0555;
Nick Piggine692ab52007-07-26 13:40:43 +02006208 entry->child = sd_alloc_ctl_cpu_table(i);
Milton Miller97b6ea72007-10-15 17:00:19 +02006209 entry++;
Nick Piggine692ab52007-07-26 13:40:43 +02006210 }
Milton Miller73785472007-10-24 18:23:48 +02006211
6212 WARN_ON(sd_sysctl_header);
Nick Piggine692ab52007-07-26 13:40:43 +02006213 sd_sysctl_header = register_sysctl_table(sd_ctl_root);
6214}
Milton Miller6382bc92007-10-15 17:00:19 +02006215
Milton Miller73785472007-10-24 18:23:48 +02006216/* may be called multiple times per register */
Milton Miller6382bc92007-10-15 17:00:19 +02006217static void unregister_sched_domain_sysctl(void)
6218{
Milton Miller73785472007-10-24 18:23:48 +02006219 if (sd_sysctl_header)
6220 unregister_sysctl_table(sd_sysctl_header);
Milton Miller6382bc92007-10-15 17:00:19 +02006221 sd_sysctl_header = NULL;
Milton Miller73785472007-10-24 18:23:48 +02006222 if (sd_ctl_dir[0].child)
6223 sd_free_ctl_entry(&sd_ctl_dir[0].child);
Milton Miller6382bc92007-10-15 17:00:19 +02006224}
Nick Piggine692ab52007-07-26 13:40:43 +02006225#else
Milton Miller6382bc92007-10-15 17:00:19 +02006226static void register_sched_domain_sysctl(void)
6227{
6228}
6229static void unregister_sched_domain_sysctl(void)
Nick Piggine692ab52007-07-26 13:40:43 +02006230{
6231}
6232#endif
6233
Gregory Haskins1f11eb62008-06-04 15:04:05 -04006234static void set_rq_online(struct rq *rq)
6235{
6236 if (!rq->online) {
6237 const struct sched_class *class;
6238
6239 cpu_set(rq->cpu, rq->rd->online);
6240 rq->online = 1;
6241
6242 for_each_class(class) {
6243 if (class->rq_online)
6244 class->rq_online(rq);
6245 }
6246 }
6247}
6248
6249static void set_rq_offline(struct rq *rq)
6250{
6251 if (rq->online) {
6252 const struct sched_class *class;
6253
6254 for_each_class(class) {
6255 if (class->rq_offline)
6256 class->rq_offline(rq);
6257 }
6258
6259 cpu_clear(rq->cpu, rq->rd->online);
6260 rq->online = 0;
6261 }
6262}
6263
Linus Torvalds1da177e2005-04-16 15:20:36 -07006264/*
6265 * migration_call - callback that gets triggered when a CPU is added.
6266 * Here we can start up the necessary migration thread for the new CPU.
6267 */
Ingo Molnar48f24c42006-07-03 00:25:40 -07006268static int __cpuinit
6269migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006270{
Linus Torvalds1da177e2005-04-16 15:20:36 -07006271 struct task_struct *p;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006272 int cpu = (long)hcpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006273 unsigned long flags;
Ingo Molnar70b97a72006-07-03 00:25:42 -07006274 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006275
6276 switch (action) {
Gautham R Shenoy5be93612007-05-09 02:34:04 -07006277
Linus Torvalds1da177e2005-04-16 15:20:36 -07006278 case CPU_UP_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07006279 case CPU_UP_PREPARE_FROZEN:
Ingo Molnardd41f592007-07-09 18:51:59 +02006280 p = kthread_create(migration_thread, hcpu, "migration/%d", cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006281 if (IS_ERR(p))
6282 return NOTIFY_BAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006283 kthread_bind(p, cpu);
6284 /* Must be high prio: stop_machine expects to yield to it. */
6285 rq = task_rq_lock(p, &flags);
Ingo Molnardd41f592007-07-09 18:51:59 +02006286 __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006287 task_rq_unlock(rq, &flags);
6288 cpu_rq(cpu)->migration_thread = p;
6289 break;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006290
Linus Torvalds1da177e2005-04-16 15:20:36 -07006291 case CPU_ONLINE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07006292 case CPU_ONLINE_FROZEN:
Robert P. J. Day3a4fa0a2007-10-19 23:10:43 +02006293 /* Strictly unnecessary, as first user will wake it. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006294 wake_up_process(cpu_rq(cpu)->migration_thread);
Gregory Haskins1f94ef52008-03-10 16:52:41 -04006295
6296 /* Update our root-domain */
6297 rq = cpu_rq(cpu);
6298 spin_lock_irqsave(&rq->lock, flags);
6299 if (rq->rd) {
6300 BUG_ON(!cpu_isset(cpu, rq->rd->span));
Gregory Haskins1f11eb62008-06-04 15:04:05 -04006301
6302 set_rq_online(rq);
Gregory Haskins1f94ef52008-03-10 16:52:41 -04006303 }
6304 spin_unlock_irqrestore(&rq->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006305 break;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006306
Linus Torvalds1da177e2005-04-16 15:20:36 -07006307#ifdef CONFIG_HOTPLUG_CPU
6308 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07006309 case CPU_UP_CANCELED_FROZEN:
Heiko Carstensfc75cdf2006-06-25 05:49:10 -07006310 if (!cpu_rq(cpu)->migration_thread)
6311 break;
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006312 /* Unbind it from offline cpu so it can run. Fall thru. */
Heiko Carstensa4c4af72005-11-07 00:58:38 -08006313 kthread_bind(cpu_rq(cpu)->migration_thread,
6314 any_online_cpu(cpu_online_map));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006315 kthread_stop(cpu_rq(cpu)->migration_thread);
6316 cpu_rq(cpu)->migration_thread = NULL;
6317 break;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006318
Linus Torvalds1da177e2005-04-16 15:20:36 -07006319 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07006320 case CPU_DEAD_FROZEN:
Cliff Wickman470fd642007-10-18 23:40:46 -07006321 cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006322 migrate_live_tasks(cpu);
6323 rq = cpu_rq(cpu);
6324 kthread_stop(rq->migration_thread);
6325 rq->migration_thread = NULL;
6326 /* Idle task back to normal (off runqueue, low prio) */
Oleg Nesterovd2da2722007-10-16 23:30:56 -07006327 spin_lock_irq(&rq->lock);
Ingo Molnara8e504d2007-08-09 11:16:47 +02006328 update_rq_clock(rq);
Ingo Molnar2e1cb742007-08-09 11:16:49 +02006329 deactivate_task(rq, rq->idle, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006330 rq->idle->static_prio = MAX_PRIO;
Ingo Molnardd41f592007-07-09 18:51:59 +02006331 __setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
6332 rq->idle->sched_class = &idle_sched_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006333 migrate_dead_tasks(cpu);
Oleg Nesterovd2da2722007-10-16 23:30:56 -07006334 spin_unlock_irq(&rq->lock);
Cliff Wickman470fd642007-10-18 23:40:46 -07006335 cpuset_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07006336 migrate_nr_uninterruptible(rq);
6337 BUG_ON(rq->nr_running != 0);
6338
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006339 /*
6340 * No need to migrate the tasks: it was best-effort if
6341 * they didn't take sched_hotcpu_mutex. Just wake up
6342 * the requestors.
6343 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006344 spin_lock_irq(&rq->lock);
6345 while (!list_empty(&rq->migration_queue)) {
Ingo Molnar70b97a72006-07-03 00:25:42 -07006346 struct migration_req *req;
6347
Linus Torvalds1da177e2005-04-16 15:20:36 -07006348 req = list_entry(rq->migration_queue.next,
Ingo Molnar70b97a72006-07-03 00:25:42 -07006349 struct migration_req, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006350 list_del_init(&req->list);
6351 complete(&req->done);
6352 }
6353 spin_unlock_irq(&rq->lock);
6354 break;
Gregory Haskins57d885f2008-01-25 21:08:18 +01006355
Gregory Haskins08f503b2008-03-10 17:59:11 -04006356 case CPU_DYING:
6357 case CPU_DYING_FROZEN:
Gregory Haskins57d885f2008-01-25 21:08:18 +01006358 /* Update our root-domain */
6359 rq = cpu_rq(cpu);
6360 spin_lock_irqsave(&rq->lock, flags);
6361 if (rq->rd) {
6362 BUG_ON(!cpu_isset(cpu, rq->rd->span));
Gregory Haskins1f11eb62008-06-04 15:04:05 -04006363 set_rq_offline(rq);
Gregory Haskins57d885f2008-01-25 21:08:18 +01006364 }
6365 spin_unlock_irqrestore(&rq->lock, flags);
6366 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006367#endif
6368 }
6369 return NOTIFY_OK;
6370}
6371
6372/* Register at highest priority so that task migration (migrate_all_tasks)
6373 * happens before everything else.
6374 */
Chandra Seetharaman26c21432006-06-27 02:54:10 -07006375static struct notifier_block __cpuinitdata migration_notifier = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07006376 .notifier_call = migration_call,
6377 .priority = 10
6378};
6379
Adrian Bunke6fe6642007-11-09 22:39:39 +01006380void __init migration_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006381{
6382 void *cpu = (void *)(long)smp_processor_id();
Akinobu Mita07dccf32006-09-29 02:00:22 -07006383 int err;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006384
6385 /* Start one for the boot CPU: */
Akinobu Mita07dccf32006-09-29 02:00:22 -07006386 err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
6387 BUG_ON(err == NOTIFY_BAD);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006388 migration_call(&migration_notifier, CPU_ONLINE, cpu);
6389 register_cpu_notifier(&migration_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006390}
6391#endif
6392
6393#ifdef CONFIG_SMP
Christoph Lameter476f3532007-05-06 14:48:58 -07006394
Ingo Molnar3e9830d2007-10-15 17:00:13 +02006395#ifdef CONFIG_SCHED_DEBUG
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006396
Gautham R Shenoy099f98c2008-05-29 20:56:32 +05306397static inline const char *sd_level_to_string(enum sched_domain_level lvl)
6398{
6399 switch (lvl) {
6400 case SD_LV_NONE:
6401 return "NONE";
6402 case SD_LV_SIBLING:
6403 return "SIBLING";
6404 case SD_LV_MC:
6405 return "MC";
6406 case SD_LV_CPU:
6407 return "CPU";
6408 case SD_LV_NODE:
6409 return "NODE";
6410 case SD_LV_ALLNODES:
6411 return "ALLNODES";
6412 case SD_LV_MAX:
6413 return "MAX";
6414
6415 }
6416 return "MAX";
6417}
6418
Mike Travis7c16ec52008-04-04 18:11:11 -07006419static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
6420 cpumask_t *groupmask)
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006421{
6422 struct sched_group *group = sd->groups;
Mike Travis434d53b2008-04-04 18:11:04 -07006423 char str[256];
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006424
Mike Travis434d53b2008-04-04 18:11:04 -07006425 cpulist_scnprintf(str, sizeof(str), sd->span);
Mike Travis7c16ec52008-04-04 18:11:11 -07006426 cpus_clear(*groupmask);
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006427
6428 printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
6429
6430 if (!(sd->flags & SD_LOAD_BALANCE)) {
6431 printk("does not load-balance\n");
6432 if (sd->parent)
6433 printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
6434 " has parent");
6435 return -1;
6436 }
6437
Gautham R Shenoy099f98c2008-05-29 20:56:32 +05306438 printk(KERN_CONT "span %s level %s\n",
6439 str, sd_level_to_string(sd->level));
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006440
6441 if (!cpu_isset(cpu, sd->span)) {
6442 printk(KERN_ERR "ERROR: domain->span does not contain "
6443 "CPU%d\n", cpu);
6444 }
6445 if (!cpu_isset(cpu, group->cpumask)) {
6446 printk(KERN_ERR "ERROR: domain->groups does not contain"
6447 " CPU%d\n", cpu);
6448 }
6449
6450 printk(KERN_DEBUG "%*s groups:", level + 1, "");
6451 do {
6452 if (!group) {
6453 printk("\n");
6454 printk(KERN_ERR "ERROR: group is NULL\n");
6455 break;
6456 }
6457
6458 if (!group->__cpu_power) {
6459 printk(KERN_CONT "\n");
6460 printk(KERN_ERR "ERROR: domain->cpu_power not "
6461 "set\n");
6462 break;
6463 }
6464
6465 if (!cpus_weight(group->cpumask)) {
6466 printk(KERN_CONT "\n");
6467 printk(KERN_ERR "ERROR: empty group\n");
6468 break;
6469 }
6470
Mike Travis7c16ec52008-04-04 18:11:11 -07006471 if (cpus_intersects(*groupmask, group->cpumask)) {
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006472 printk(KERN_CONT "\n");
6473 printk(KERN_ERR "ERROR: repeated CPUs\n");
6474 break;
6475 }
6476
Mike Travis7c16ec52008-04-04 18:11:11 -07006477 cpus_or(*groupmask, *groupmask, group->cpumask);
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006478
Mike Travis434d53b2008-04-04 18:11:04 -07006479 cpulist_scnprintf(str, sizeof(str), group->cpumask);
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006480 printk(KERN_CONT " %s", str);
6481
6482 group = group->next;
6483 } while (group != sd->groups);
6484 printk(KERN_CONT "\n");
6485
Mike Travis7c16ec52008-04-04 18:11:11 -07006486 if (!cpus_equal(sd->span, *groupmask))
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006487 printk(KERN_ERR "ERROR: groups don't span domain->span\n");
6488
Mike Travis7c16ec52008-04-04 18:11:11 -07006489 if (sd->parent && !cpus_subset(*groupmask, sd->parent->span))
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006490 printk(KERN_ERR "ERROR: parent span is not a superset "
6491 "of domain->span\n");
6492 return 0;
6493}
6494
Linus Torvalds1da177e2005-04-16 15:20:36 -07006495static void sched_domain_debug(struct sched_domain *sd, int cpu)
6496{
Mike Travis7c16ec52008-04-04 18:11:11 -07006497 cpumask_t *groupmask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006498 int level = 0;
6499
Nick Piggin41c7ce92005-06-25 14:57:24 -07006500 if (!sd) {
6501 printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
6502 return;
6503 }
6504
Linus Torvalds1da177e2005-04-16 15:20:36 -07006505 printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
6506
Mike Travis7c16ec52008-04-04 18:11:11 -07006507 groupmask = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
6508 if (!groupmask) {
6509 printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
6510 return;
6511 }
6512
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006513 for (;;) {
Mike Travis7c16ec52008-04-04 18:11:11 -07006514 if (sched_domain_debug_one(sd, cpu, level, groupmask))
Linus Torvalds1da177e2005-04-16 15:20:36 -07006515 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006516 level++;
6517 sd = sd->parent;
Miguel Ojeda Sandonis33859f72006-12-10 02:20:38 -08006518 if (!sd)
Ingo Molnar4dcf6af2007-10-24 18:23:48 +02006519 break;
6520 }
Mike Travis7c16ec52008-04-04 18:11:11 -07006521 kfree(groupmask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006522}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006523#else /* !CONFIG_SCHED_DEBUG */
Ingo Molnar48f24c42006-07-03 00:25:40 -07006524# define sched_domain_debug(sd, cpu) do { } while (0)
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006525#endif /* CONFIG_SCHED_DEBUG */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006526
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07006527static int sd_degenerate(struct sched_domain *sd)
Suresh Siddha245af2c2005-06-25 14:57:25 -07006528{
6529 if (cpus_weight(sd->span) == 1)
6530 return 1;
6531
6532 /* Following flags need at least 2 groups */
6533 if (sd->flags & (SD_LOAD_BALANCE |
6534 SD_BALANCE_NEWIDLE |
6535 SD_BALANCE_FORK |
Siddha, Suresh B89c47102006-10-03 01:14:09 -07006536 SD_BALANCE_EXEC |
6537 SD_SHARE_CPUPOWER |
6538 SD_SHARE_PKG_RESOURCES)) {
Suresh Siddha245af2c2005-06-25 14:57:25 -07006539 if (sd->groups != sd->groups->next)
6540 return 0;
6541 }
6542
6543 /* Following flags don't use groups */
6544 if (sd->flags & (SD_WAKE_IDLE |
6545 SD_WAKE_AFFINE |
6546 SD_WAKE_BALANCE))
6547 return 0;
6548
6549 return 1;
6550}
6551
Ingo Molnar48f24c42006-07-03 00:25:40 -07006552static int
6553sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
Suresh Siddha245af2c2005-06-25 14:57:25 -07006554{
6555 unsigned long cflags = sd->flags, pflags = parent->flags;
6556
6557 if (sd_degenerate(parent))
6558 return 1;
6559
6560 if (!cpus_equal(sd->span, parent->span))
6561 return 0;
6562
6563 /* Does parent contain flags not in child? */
6564 /* WAKE_BALANCE is a subset of WAKE_AFFINE */
6565 if (cflags & SD_WAKE_AFFINE)
6566 pflags &= ~SD_WAKE_BALANCE;
6567 /* Flags needing groups don't count if only 1 group in parent */
6568 if (parent->groups == parent->groups->next) {
6569 pflags &= ~(SD_LOAD_BALANCE |
6570 SD_BALANCE_NEWIDLE |
6571 SD_BALANCE_FORK |
Siddha, Suresh B89c47102006-10-03 01:14:09 -07006572 SD_BALANCE_EXEC |
6573 SD_SHARE_CPUPOWER |
6574 SD_SHARE_PKG_RESOURCES);
Suresh Siddha245af2c2005-06-25 14:57:25 -07006575 }
6576 if (~cflags & pflags)
6577 return 0;
6578
6579 return 1;
6580}
6581
Gregory Haskins57d885f2008-01-25 21:08:18 +01006582static void rq_attach_root(struct rq *rq, struct root_domain *rd)
6583{
6584 unsigned long flags;
Gregory Haskins57d885f2008-01-25 21:08:18 +01006585
6586 spin_lock_irqsave(&rq->lock, flags);
6587
6588 if (rq->rd) {
6589 struct root_domain *old_rd = rq->rd;
6590
Gregory Haskins1f11eb62008-06-04 15:04:05 -04006591 if (cpu_isset(rq->cpu, old_rd->online))
6592 set_rq_offline(rq);
Gregory Haskins57d885f2008-01-25 21:08:18 +01006593
Gregory Haskinsdc938522008-01-25 21:08:26 +01006594 cpu_clear(rq->cpu, old_rd->span);
Gregory Haskinsdc938522008-01-25 21:08:26 +01006595
Gregory Haskins57d885f2008-01-25 21:08:18 +01006596 if (atomic_dec_and_test(&old_rd->refcount))
6597 kfree(old_rd);
6598 }
6599
6600 atomic_inc(&rd->refcount);
6601 rq->rd = rd;
6602
Gregory Haskinsdc938522008-01-25 21:08:26 +01006603 cpu_set(rq->cpu, rd->span);
Gregory Haskins1f94ef52008-03-10 16:52:41 -04006604 if (cpu_isset(rq->cpu, cpu_online_map))
Gregory Haskins1f11eb62008-06-04 15:04:05 -04006605 set_rq_online(rq);
Gregory Haskins57d885f2008-01-25 21:08:18 +01006606
6607 spin_unlock_irqrestore(&rq->lock, flags);
6608}
6609
Gregory Haskinsdc938522008-01-25 21:08:26 +01006610static void init_rootdomain(struct root_domain *rd)
Gregory Haskins57d885f2008-01-25 21:08:18 +01006611{
6612 memset(rd, 0, sizeof(*rd));
6613
Gregory Haskinsdc938522008-01-25 21:08:26 +01006614 cpus_clear(rd->span);
6615 cpus_clear(rd->online);
Gregory Haskins6e0534f2008-05-12 21:21:01 +02006616
6617 cpupri_init(&rd->cpupri);
Gregory Haskins57d885f2008-01-25 21:08:18 +01006618}
6619
6620static void init_defrootdomain(void)
6621{
Gregory Haskinsdc938522008-01-25 21:08:26 +01006622 init_rootdomain(&def_root_domain);
Gregory Haskins57d885f2008-01-25 21:08:18 +01006623 atomic_set(&def_root_domain.refcount, 1);
6624}
6625
Gregory Haskinsdc938522008-01-25 21:08:26 +01006626static struct root_domain *alloc_rootdomain(void)
Gregory Haskins57d885f2008-01-25 21:08:18 +01006627{
6628 struct root_domain *rd;
6629
6630 rd = kmalloc(sizeof(*rd), GFP_KERNEL);
6631 if (!rd)
6632 return NULL;
6633
Gregory Haskinsdc938522008-01-25 21:08:26 +01006634 init_rootdomain(rd);
Gregory Haskins57d885f2008-01-25 21:08:18 +01006635
6636 return rd;
6637}
6638
Linus Torvalds1da177e2005-04-16 15:20:36 -07006639/*
Ingo Molnar0eab9142008-01-25 21:08:19 +01006640 * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
Linus Torvalds1da177e2005-04-16 15:20:36 -07006641 * hold the hotplug lock.
6642 */
Ingo Molnar0eab9142008-01-25 21:08:19 +01006643static void
6644cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006645{
Ingo Molnar70b97a72006-07-03 00:25:42 -07006646 struct rq *rq = cpu_rq(cpu);
Suresh Siddha245af2c2005-06-25 14:57:25 -07006647 struct sched_domain *tmp;
6648
6649 /* Remove the sched domains which do not contribute to scheduling. */
6650 for (tmp = sd; tmp; tmp = tmp->parent) {
6651 struct sched_domain *parent = tmp->parent;
6652 if (!parent)
6653 break;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07006654 if (sd_parent_degenerate(tmp, parent)) {
Suresh Siddha245af2c2005-06-25 14:57:25 -07006655 tmp->parent = parent->parent;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07006656 if (parent->parent)
6657 parent->parent->child = tmp;
6658 }
Suresh Siddha245af2c2005-06-25 14:57:25 -07006659 }
6660
Siddha, Suresh B1a848872006-10-03 01:14:08 -07006661 if (sd && sd_degenerate(sd)) {
Suresh Siddha245af2c2005-06-25 14:57:25 -07006662 sd = sd->parent;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07006663 if (sd)
6664 sd->child = NULL;
6665 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07006666
6667 sched_domain_debug(sd, cpu);
6668
Gregory Haskins57d885f2008-01-25 21:08:18 +01006669 rq_attach_root(rq, rd);
Nick Piggin674311d2005-06-25 14:57:27 -07006670 rcu_assign_pointer(rq->sd, sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006671}
6672
6673/* cpus with isolated domains */
Tim Chen67af63a2006-12-22 01:07:50 -08006674static cpumask_t cpu_isolated_map = CPU_MASK_NONE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006675
6676/* Setup the mask of cpus configured for isolated domains */
6677static int __init isolated_cpu_setup(char *str)
6678{
6679 int ints[NR_CPUS], i;
6680
6681 str = get_options(str, ARRAY_SIZE(ints), ints);
6682 cpus_clear(cpu_isolated_map);
6683 for (i = 1; i <= ints[0]; i++)
6684 if (ints[i] < NR_CPUS)
6685 cpu_set(ints[i], cpu_isolated_map);
6686 return 1;
6687}
6688
Ingo Molnar8927f492007-10-15 17:00:13 +02006689__setup("isolcpus=", isolated_cpu_setup);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006690
6691/*
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006692 * init_sched_build_groups takes the cpumask we wish to span, and a pointer
6693 * to a function which identifies what group(along with sched group) a CPU
6694 * belongs to. The return value of group_fn must be a >= 0 and < NR_CPUS
6695 * (due to the fact that we keep track of groups covered with a cpumask_t).
Linus Torvalds1da177e2005-04-16 15:20:36 -07006696 *
6697 * init_sched_build_groups will build a circular linked list of the groups
6698 * covered by the given span, and will set each group's ->cpumask correctly,
6699 * and ->cpu_power to 0.
6700 */
Siddha, Suresh Ba6160582006-10-03 01:14:06 -07006701static void
Mike Travis7c16ec52008-04-04 18:11:11 -07006702init_sched_build_groups(const cpumask_t *span, const cpumask_t *cpu_map,
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006703 int (*group_fn)(int cpu, const cpumask_t *cpu_map,
Mike Travis7c16ec52008-04-04 18:11:11 -07006704 struct sched_group **sg,
6705 cpumask_t *tmpmask),
6706 cpumask_t *covered, cpumask_t *tmpmask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006707{
6708 struct sched_group *first = NULL, *last = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006709 int i;
6710
Mike Travis7c16ec52008-04-04 18:11:11 -07006711 cpus_clear(*covered);
6712
6713 for_each_cpu_mask(i, *span) {
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006714 struct sched_group *sg;
Mike Travis7c16ec52008-04-04 18:11:11 -07006715 int group = group_fn(i, cpu_map, &sg, tmpmask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006716 int j;
6717
Mike Travis7c16ec52008-04-04 18:11:11 -07006718 if (cpu_isset(i, *covered))
Linus Torvalds1da177e2005-04-16 15:20:36 -07006719 continue;
6720
Mike Travis7c16ec52008-04-04 18:11:11 -07006721 cpus_clear(sg->cpumask);
Eric Dumazet5517d862007-05-08 00:32:57 -07006722 sg->__cpu_power = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006723
Mike Travis7c16ec52008-04-04 18:11:11 -07006724 for_each_cpu_mask(j, *span) {
6725 if (group_fn(j, cpu_map, NULL, tmpmask) != group)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006726 continue;
6727
Mike Travis7c16ec52008-04-04 18:11:11 -07006728 cpu_set(j, *covered);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006729 cpu_set(j, sg->cpumask);
6730 }
6731 if (!first)
6732 first = sg;
6733 if (last)
6734 last->next = sg;
6735 last = sg;
6736 }
6737 last->next = first;
6738}
6739
John Hawkes9c1cfda2005-09-06 15:18:14 -07006740#define SD_NODES_PER_DOMAIN 16
Linus Torvalds1da177e2005-04-16 15:20:36 -07006741
John Hawkes9c1cfda2005-09-06 15:18:14 -07006742#ifdef CONFIG_NUMA
akpm@osdl.org198e2f12006-01-12 01:05:30 -08006743
John Hawkes9c1cfda2005-09-06 15:18:14 -07006744/**
6745 * find_next_best_node - find the next node to include in a sched_domain
6746 * @node: node whose sched_domain we're building
6747 * @used_nodes: nodes already in the sched_domain
6748 *
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006749 * Find the next node to include in a given scheduling domain. Simply
John Hawkes9c1cfda2005-09-06 15:18:14 -07006750 * finds the closest node not already in the @used_nodes map.
6751 *
6752 * Should use nodemask_t.
6753 */
Mike Travisc5f59f02008-04-04 18:11:10 -07006754static int find_next_best_node(int node, nodemask_t *used_nodes)
John Hawkes9c1cfda2005-09-06 15:18:14 -07006755{
6756 int i, n, val, min_val, best_node = 0;
6757
6758 min_val = INT_MAX;
6759
6760 for (i = 0; i < MAX_NUMNODES; i++) {
6761 /* Start at @node */
6762 n = (node + i) % MAX_NUMNODES;
6763
6764 if (!nr_cpus_node(n))
6765 continue;
6766
6767 /* Skip already used nodes */
Mike Travisc5f59f02008-04-04 18:11:10 -07006768 if (node_isset(n, *used_nodes))
John Hawkes9c1cfda2005-09-06 15:18:14 -07006769 continue;
6770
6771 /* Simple min distance search */
6772 val = node_distance(node, n);
6773
6774 if (val < min_val) {
6775 min_val = val;
6776 best_node = n;
6777 }
6778 }
6779
Mike Travisc5f59f02008-04-04 18:11:10 -07006780 node_set(best_node, *used_nodes);
John Hawkes9c1cfda2005-09-06 15:18:14 -07006781 return best_node;
6782}
6783
6784/**
6785 * sched_domain_node_span - get a cpumask for a node's sched_domain
6786 * @node: node whose cpumask we're constructing
Randy Dunlap73486722008-04-22 10:07:22 -07006787 * @span: resulting cpumask
John Hawkes9c1cfda2005-09-06 15:18:14 -07006788 *
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006789 * Given a node, construct a good cpumask for its sched_domain to span. It
John Hawkes9c1cfda2005-09-06 15:18:14 -07006790 * should be one that prevents unnecessary balancing, but also spreads tasks
6791 * out optimally.
6792 */
Mike Travis4bdbaad32008-04-15 16:35:52 -07006793static void sched_domain_node_span(int node, cpumask_t *span)
John Hawkes9c1cfda2005-09-06 15:18:14 -07006794{
Mike Travisc5f59f02008-04-04 18:11:10 -07006795 nodemask_t used_nodes;
Mike Travisc5f59f02008-04-04 18:11:10 -07006796 node_to_cpumask_ptr(nodemask, node);
Ingo Molnar48f24c42006-07-03 00:25:40 -07006797 int i;
John Hawkes9c1cfda2005-09-06 15:18:14 -07006798
Mike Travis4bdbaad32008-04-15 16:35:52 -07006799 cpus_clear(*span);
Mike Travisc5f59f02008-04-04 18:11:10 -07006800 nodes_clear(used_nodes);
John Hawkes9c1cfda2005-09-06 15:18:14 -07006801
Mike Travis4bdbaad32008-04-15 16:35:52 -07006802 cpus_or(*span, *span, *nodemask);
Mike Travisc5f59f02008-04-04 18:11:10 -07006803 node_set(node, used_nodes);
John Hawkes9c1cfda2005-09-06 15:18:14 -07006804
6805 for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
Mike Travisc5f59f02008-04-04 18:11:10 -07006806 int next_node = find_next_best_node(node, &used_nodes);
Ingo Molnar48f24c42006-07-03 00:25:40 -07006807
Mike Travisc5f59f02008-04-04 18:11:10 -07006808 node_to_cpumask_ptr_next(nodemask, next_node);
Mike Travis4bdbaad32008-04-15 16:35:52 -07006809 cpus_or(*span, *span, *nodemask);
John Hawkes9c1cfda2005-09-06 15:18:14 -07006810 }
John Hawkes9c1cfda2005-09-06 15:18:14 -07006811}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006812#endif /* CONFIG_NUMA */
John Hawkes9c1cfda2005-09-06 15:18:14 -07006813
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07006814int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006815
John Hawkes9c1cfda2005-09-06 15:18:14 -07006816/*
Ingo Molnar48f24c42006-07-03 00:25:40 -07006817 * SMT sched-domains:
John Hawkes9c1cfda2005-09-06 15:18:14 -07006818 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006819#ifdef CONFIG_SCHED_SMT
6820static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006821static DEFINE_PER_CPU(struct sched_group, sched_group_cpus);
Ingo Molnar48f24c42006-07-03 00:25:40 -07006822
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006823static int
Mike Travis7c16ec52008-04-04 18:11:11 -07006824cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
6825 cpumask_t *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006826{
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006827 if (sg)
6828 *sg = &per_cpu(sched_group_cpus, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006829 return cpu;
6830}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006831#endif /* CONFIG_SCHED_SMT */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006832
Ingo Molnar48f24c42006-07-03 00:25:40 -07006833/*
6834 * multi-core sched-domains:
6835 */
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006836#ifdef CONFIG_SCHED_MC
6837static DEFINE_PER_CPU(struct sched_domain, core_domains);
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006838static DEFINE_PER_CPU(struct sched_group, sched_group_core);
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006839#endif /* CONFIG_SCHED_MC */
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006840
6841#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006842static int
Mike Travis7c16ec52008-04-04 18:11:11 -07006843cpu_to_core_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
6844 cpumask_t *mask)
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006845{
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006846 int group;
Mike Travis7c16ec52008-04-04 18:11:11 -07006847
6848 *mask = per_cpu(cpu_sibling_map, cpu);
6849 cpus_and(*mask, *mask, *cpu_map);
6850 group = first_cpu(*mask);
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006851 if (sg)
6852 *sg = &per_cpu(sched_group_core, group);
6853 return group;
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006854}
6855#elif defined(CONFIG_SCHED_MC)
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006856static int
Mike Travis7c16ec52008-04-04 18:11:11 -07006857cpu_to_core_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
6858 cpumask_t *unused)
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006859{
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006860 if (sg)
6861 *sg = &per_cpu(sched_group_core, cpu);
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006862 return cpu;
6863}
6864#endif
6865
Linus Torvalds1da177e2005-04-16 15:20:36 -07006866static DEFINE_PER_CPU(struct sched_domain, phys_domains);
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006867static DEFINE_PER_CPU(struct sched_group, sched_group_phys);
Ingo Molnar48f24c42006-07-03 00:25:40 -07006868
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01006869static int
Mike Travis7c16ec52008-04-04 18:11:11 -07006870cpu_to_phys_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
6871 cpumask_t *mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006872{
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006873 int group;
Ingo Molnar48f24c42006-07-03 00:25:40 -07006874#ifdef CONFIG_SCHED_MC
Mike Travis7c16ec52008-04-04 18:11:11 -07006875 *mask = cpu_coregroup_map(cpu);
6876 cpus_and(*mask, *mask, *cpu_map);
6877 group = first_cpu(*mask);
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08006878#elif defined(CONFIG_SCHED_SMT)
Mike Travis7c16ec52008-04-04 18:11:11 -07006879 *mask = per_cpu(cpu_sibling_map, cpu);
6880 cpus_and(*mask, *mask, *cpu_map);
6881 group = first_cpu(*mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006882#else
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006883 group = cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006884#endif
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006885 if (sg)
6886 *sg = &per_cpu(sched_group_phys, group);
6887 return group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006888}
6889
6890#ifdef CONFIG_NUMA
John Hawkes9c1cfda2005-09-06 15:18:14 -07006891/*
6892 * The init_sched_build_groups can't handle what we want to do with node
6893 * groups, so roll our own. Now each node has its own list of groups which
6894 * gets dynamically allocated.
6895 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006896static DEFINE_PER_CPU(struct sched_domain, node_domains);
Mike Travis434d53b2008-04-04 18:11:04 -07006897static struct sched_group ***sched_group_nodes_bycpu;
John Hawkes9c1cfda2005-09-06 15:18:14 -07006898
6899static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006900static DEFINE_PER_CPU(struct sched_group, sched_group_allnodes);
John Hawkes9c1cfda2005-09-06 15:18:14 -07006901
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006902static int cpu_to_allnodes_group(int cpu, const cpumask_t *cpu_map,
Mike Travis7c16ec52008-04-04 18:11:11 -07006903 struct sched_group **sg, cpumask_t *nodemask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006904{
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006905 int group;
6906
Mike Travis7c16ec52008-04-04 18:11:11 -07006907 *nodemask = node_to_cpumask(cpu_to_node(cpu));
6908 cpus_and(*nodemask, *nodemask, *cpu_map);
6909 group = first_cpu(*nodemask);
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006910
6911 if (sg)
6912 *sg = &per_cpu(sched_group_allnodes, group);
6913 return group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006914}
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08006915
Siddha, Suresh B08069032006-03-27 01:15:23 -08006916static void init_numa_sched_groups_power(struct sched_group *group_head)
6917{
6918 struct sched_group *sg = group_head;
6919 int j;
6920
6921 if (!sg)
6922 return;
Andi Kleen3a5c3592007-10-15 17:00:14 +02006923 do {
6924 for_each_cpu_mask(j, sg->cpumask) {
6925 struct sched_domain *sd;
Siddha, Suresh B08069032006-03-27 01:15:23 -08006926
Andi Kleen3a5c3592007-10-15 17:00:14 +02006927 sd = &per_cpu(phys_domains, j);
6928 if (j != first_cpu(sd->groups->cpumask)) {
6929 /*
6930 * Only add "power" once for each
6931 * physical package.
6932 */
6933 continue;
6934 }
6935
6936 sg_inc_cpu_power(sg, sd->groups->__cpu_power);
Siddha, Suresh B08069032006-03-27 01:15:23 -08006937 }
Andi Kleen3a5c3592007-10-15 17:00:14 +02006938 sg = sg->next;
6939 } while (sg != group_head);
Siddha, Suresh B08069032006-03-27 01:15:23 -08006940}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006941#endif /* CONFIG_NUMA */
Linus Torvalds1da177e2005-04-16 15:20:36 -07006942
Siddha, Suresh Ba6160582006-10-03 01:14:06 -07006943#ifdef CONFIG_NUMA
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006944/* Free memory allocated for various sched_group structures */
Mike Travis7c16ec52008-04-04 18:11:11 -07006945static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask)
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006946{
Siddha, Suresh Ba6160582006-10-03 01:14:06 -07006947 int cpu, i;
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006948
6949 for_each_cpu_mask(cpu, *cpu_map) {
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006950 struct sched_group **sched_group_nodes
6951 = sched_group_nodes_bycpu[cpu];
6952
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006953 if (!sched_group_nodes)
6954 continue;
6955
6956 for (i = 0; i < MAX_NUMNODES; i++) {
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006957 struct sched_group *oldsg, *sg = sched_group_nodes[i];
6958
Mike Travis7c16ec52008-04-04 18:11:11 -07006959 *nodemask = node_to_cpumask(i);
6960 cpus_and(*nodemask, *nodemask, *cpu_map);
6961 if (cpus_empty(*nodemask))
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006962 continue;
6963
6964 if (sg == NULL)
6965 continue;
6966 sg = sg->next;
6967next_sg:
6968 oldsg = sg;
6969 sg = sg->next;
6970 kfree(oldsg);
6971 if (oldsg != sched_group_nodes[i])
6972 goto next_sg;
6973 }
6974 kfree(sched_group_nodes);
6975 sched_group_nodes_bycpu[cpu] = NULL;
6976 }
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006977}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006978#else /* !CONFIG_NUMA */
Mike Travis7c16ec52008-04-04 18:11:11 -07006979static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask)
Siddha, Suresh Ba6160582006-10-03 01:14:06 -07006980{
6981}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02006982#endif /* CONFIG_NUMA */
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07006983
Linus Torvalds1da177e2005-04-16 15:20:36 -07006984/*
Siddha, Suresh B89c47102006-10-03 01:14:09 -07006985 * Initialize sched groups cpu_power.
6986 *
6987 * cpu_power indicates the capacity of sched group, which is used while
6988 * distributing the load between different sched groups in a sched domain.
6989 * Typically cpu_power for all the groups in a sched domain will be same unless
6990 * there are asymmetries in the topology. If there are asymmetries, group
6991 * having more cpu_power will pickup more load compared to the group having
6992 * less cpu_power.
6993 *
6994 * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
6995 * the maximum number of tasks a group can handle in the presence of other idle
6996 * or lightly loaded groups in the same sched domain.
6997 */
6998static void init_sched_groups_power(int cpu, struct sched_domain *sd)
6999{
7000 struct sched_domain *child;
7001 struct sched_group *group;
7002
7003 WARN_ON(!sd || !sd->groups);
7004
7005 if (cpu != first_cpu(sd->groups->cpumask))
7006 return;
7007
7008 child = sd->child;
7009
Eric Dumazet5517d862007-05-08 00:32:57 -07007010 sd->groups->__cpu_power = 0;
7011
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007012 /*
7013 * For perf policy, if the groups in child domain share resources
7014 * (for example cores sharing some portions of the cache hierarchy
7015 * or SMT), then set this domain groups cpu_power such that each group
7016 * can handle only one task, when there are other idle groups in the
7017 * same sched domain.
7018 */
7019 if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
7020 (child->flags &
7021 (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
Eric Dumazet5517d862007-05-08 00:32:57 -07007022 sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007023 return;
7024 }
7025
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007026 /*
7027 * add cpu_power of each child group to this groups cpu_power
7028 */
7029 group = child->groups;
7030 do {
Eric Dumazet5517d862007-05-08 00:32:57 -07007031 sg_inc_cpu_power(sd->groups, group->__cpu_power);
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007032 group = group->next;
7033 } while (group != child->groups);
7034}
7035
7036/*
Mike Travis7c16ec52008-04-04 18:11:11 -07007037 * Initializers for schedule domains
7038 * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
7039 */
7040
7041#define SD_INIT(sd, type) sd_init_##type(sd)
7042#define SD_INIT_FUNC(type) \
7043static noinline void sd_init_##type(struct sched_domain *sd) \
7044{ \
7045 memset(sd, 0, sizeof(*sd)); \
7046 *sd = SD_##type##_INIT; \
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007047 sd->level = SD_LV_##type; \
Mike Travis7c16ec52008-04-04 18:11:11 -07007048}
7049
7050SD_INIT_FUNC(CPU)
7051#ifdef CONFIG_NUMA
7052 SD_INIT_FUNC(ALLNODES)
7053 SD_INIT_FUNC(NODE)
7054#endif
7055#ifdef CONFIG_SCHED_SMT
7056 SD_INIT_FUNC(SIBLING)
7057#endif
7058#ifdef CONFIG_SCHED_MC
7059 SD_INIT_FUNC(MC)
7060#endif
7061
7062/*
7063 * To minimize stack usage kmalloc room for cpumasks and share the
7064 * space as the usage in build_sched_domains() dictates. Used only
7065 * if the amount of space is significant.
7066 */
7067struct allmasks {
7068 cpumask_t tmpmask; /* make this one first */
7069 union {
7070 cpumask_t nodemask;
7071 cpumask_t this_sibling_map;
7072 cpumask_t this_core_map;
7073 };
7074 cpumask_t send_covered;
7075
7076#ifdef CONFIG_NUMA
7077 cpumask_t domainspan;
7078 cpumask_t covered;
7079 cpumask_t notcovered;
7080#endif
7081};
7082
7083#if NR_CPUS > 128
7084#define SCHED_CPUMASK_ALLOC 1
7085#define SCHED_CPUMASK_FREE(v) kfree(v)
7086#define SCHED_CPUMASK_DECLARE(v) struct allmasks *v
7087#else
7088#define SCHED_CPUMASK_ALLOC 0
7089#define SCHED_CPUMASK_FREE(v)
7090#define SCHED_CPUMASK_DECLARE(v) struct allmasks _v, *v = &_v
7091#endif
7092
7093#define SCHED_CPUMASK_VAR(v, a) cpumask_t *v = (cpumask_t *) \
7094 ((unsigned long)(a) + offsetof(struct allmasks, v))
7095
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007096static int default_relax_domain_level = -1;
7097
7098static int __init setup_relax_domain_level(char *str)
7099{
Li Zefan30e0e172008-05-13 10:27:17 +08007100 unsigned long val;
7101
7102 val = simple_strtoul(str, NULL, 0);
7103 if (val < SD_LV_MAX)
7104 default_relax_domain_level = val;
7105
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007106 return 1;
7107}
7108__setup("relax_domain_level=", setup_relax_domain_level);
7109
7110static void set_domain_attribute(struct sched_domain *sd,
7111 struct sched_domain_attr *attr)
7112{
7113 int request;
7114
7115 if (!attr || attr->relax_domain_level < 0) {
7116 if (default_relax_domain_level < 0)
7117 return;
7118 else
7119 request = default_relax_domain_level;
7120 } else
7121 request = attr->relax_domain_level;
7122 if (request < sd->level) {
7123 /* turn off idle balance on this domain */
7124 sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE);
7125 } else {
7126 /* turn on idle balance on this domain */
7127 sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
7128 }
7129}
7130
Mike Travis7c16ec52008-04-04 18:11:11 -07007131/*
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007132 * Build sched domains for a given set of cpus and attach the sched domains
7133 * to the individual cpus
Linus Torvalds1da177e2005-04-16 15:20:36 -07007134 */
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007135static int __build_sched_domains(const cpumask_t *cpu_map,
7136 struct sched_domain_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07007137{
7138 int i;
Gregory Haskins57d885f2008-01-25 21:08:18 +01007139 struct root_domain *rd;
Mike Travis7c16ec52008-04-04 18:11:11 -07007140 SCHED_CPUMASK_DECLARE(allmasks);
7141 cpumask_t *tmpmask;
John Hawkesd1b55132005-09-06 15:18:14 -07007142#ifdef CONFIG_NUMA
7143 struct sched_group **sched_group_nodes = NULL;
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08007144 int sd_allnodes = 0;
John Hawkesd1b55132005-09-06 15:18:14 -07007145
7146 /*
7147 * Allocate the per-node list of sched groups
7148 */
Milton Miller5cf9f062007-10-15 17:00:19 +02007149 sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *),
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01007150 GFP_KERNEL);
John Hawkesd1b55132005-09-06 15:18:14 -07007151 if (!sched_group_nodes) {
7152 printk(KERN_WARNING "Can not alloc sched group node list\n");
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007153 return -ENOMEM;
John Hawkesd1b55132005-09-06 15:18:14 -07007154 }
John Hawkesd1b55132005-09-06 15:18:14 -07007155#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07007156
Gregory Haskinsdc938522008-01-25 21:08:26 +01007157 rd = alloc_rootdomain();
Gregory Haskins57d885f2008-01-25 21:08:18 +01007158 if (!rd) {
7159 printk(KERN_WARNING "Cannot alloc root domain\n");
Mike Travis7c16ec52008-04-04 18:11:11 -07007160#ifdef CONFIG_NUMA
7161 kfree(sched_group_nodes);
7162#endif
Gregory Haskins57d885f2008-01-25 21:08:18 +01007163 return -ENOMEM;
7164 }
7165
Mike Travis7c16ec52008-04-04 18:11:11 -07007166#if SCHED_CPUMASK_ALLOC
7167 /* get space for all scratch cpumask variables */
7168 allmasks = kmalloc(sizeof(*allmasks), GFP_KERNEL);
7169 if (!allmasks) {
7170 printk(KERN_WARNING "Cannot alloc cpumask array\n");
7171 kfree(rd);
7172#ifdef CONFIG_NUMA
7173 kfree(sched_group_nodes);
7174#endif
7175 return -ENOMEM;
7176 }
7177#endif
7178 tmpmask = (cpumask_t *)allmasks;
7179
7180
7181#ifdef CONFIG_NUMA
7182 sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes;
7183#endif
7184
Linus Torvalds1da177e2005-04-16 15:20:36 -07007185 /*
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007186 * Set up domains for cpus specified by the cpu_map.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007187 */
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007188 for_each_cpu_mask(i, *cpu_map) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07007189 struct sched_domain *sd = NULL, *p;
Mike Travis7c16ec52008-04-04 18:11:11 -07007190 SCHED_CPUMASK_VAR(nodemask, allmasks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007191
Mike Travis7c16ec52008-04-04 18:11:11 -07007192 *nodemask = node_to_cpumask(cpu_to_node(i));
7193 cpus_and(*nodemask, *nodemask, *cpu_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007194
7195#ifdef CONFIG_NUMA
Ingo Molnardd41f592007-07-09 18:51:59 +02007196 if (cpus_weight(*cpu_map) >
Mike Travis7c16ec52008-04-04 18:11:11 -07007197 SD_NODES_PER_DOMAIN*cpus_weight(*nodemask)) {
John Hawkes9c1cfda2005-09-06 15:18:14 -07007198 sd = &per_cpu(allnodes_domains, i);
Mike Travis7c16ec52008-04-04 18:11:11 -07007199 SD_INIT(sd, ALLNODES);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007200 set_domain_attribute(sd, attr);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007201 sd->span = *cpu_map;
Mike Travis7c16ec52008-04-04 18:11:11 -07007202 cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007203 p = sd;
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08007204 sd_allnodes = 1;
John Hawkes9c1cfda2005-09-06 15:18:14 -07007205 } else
7206 p = NULL;
7207
Linus Torvalds1da177e2005-04-16 15:20:36 -07007208 sd = &per_cpu(node_domains, i);
Mike Travis7c16ec52008-04-04 18:11:11 -07007209 SD_INIT(sd, NODE);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007210 set_domain_attribute(sd, attr);
Mike Travis4bdbaad32008-04-15 16:35:52 -07007211 sched_domain_node_span(cpu_to_node(i), &sd->span);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007212 sd->parent = p;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07007213 if (p)
7214 p->child = sd;
John Hawkes9c1cfda2005-09-06 15:18:14 -07007215 cpus_and(sd->span, sd->span, *cpu_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007216#endif
7217
7218 p = sd;
7219 sd = &per_cpu(phys_domains, i);
Mike Travis7c16ec52008-04-04 18:11:11 -07007220 SD_INIT(sd, CPU);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007221 set_domain_attribute(sd, attr);
Mike Travis7c16ec52008-04-04 18:11:11 -07007222 sd->span = *nodemask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07007223 sd->parent = p;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07007224 if (p)
7225 p->child = sd;
Mike Travis7c16ec52008-04-04 18:11:11 -07007226 cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007227
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007228#ifdef CONFIG_SCHED_MC
7229 p = sd;
7230 sd = &per_cpu(core_domains, i);
Mike Travis7c16ec52008-04-04 18:11:11 -07007231 SD_INIT(sd, MC);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007232 set_domain_attribute(sd, attr);
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007233 sd->span = cpu_coregroup_map(i);
7234 cpus_and(sd->span, sd->span, *cpu_map);
7235 sd->parent = p;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07007236 p->child = sd;
Mike Travis7c16ec52008-04-04 18:11:11 -07007237 cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007238#endif
7239
Linus Torvalds1da177e2005-04-16 15:20:36 -07007240#ifdef CONFIG_SCHED_SMT
7241 p = sd;
7242 sd = &per_cpu(cpu_domains, i);
Mike Travis7c16ec52008-04-04 18:11:11 -07007243 SD_INIT(sd, SIBLING);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007244 set_domain_attribute(sd, attr);
Mike Travisd5a74302007-10-16 01:24:05 -07007245 sd->span = per_cpu(cpu_sibling_map, i);
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007246 cpus_and(sd->span, sd->span, *cpu_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007247 sd->parent = p;
Siddha, Suresh B1a848872006-10-03 01:14:08 -07007248 p->child = sd;
Mike Travis7c16ec52008-04-04 18:11:11 -07007249 cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007250#endif
7251 }
7252
7253#ifdef CONFIG_SCHED_SMT
7254 /* Set up CPU (sibling) groups */
John Hawkes9c1cfda2005-09-06 15:18:14 -07007255 for_each_cpu_mask(i, *cpu_map) {
Mike Travis7c16ec52008-04-04 18:11:11 -07007256 SCHED_CPUMASK_VAR(this_sibling_map, allmasks);
7257 SCHED_CPUMASK_VAR(send_covered, allmasks);
7258
7259 *this_sibling_map = per_cpu(cpu_sibling_map, i);
7260 cpus_and(*this_sibling_map, *this_sibling_map, *cpu_map);
7261 if (i != first_cpu(*this_sibling_map))
Linus Torvalds1da177e2005-04-16 15:20:36 -07007262 continue;
7263
Ingo Molnardd41f592007-07-09 18:51:59 +02007264 init_sched_build_groups(this_sibling_map, cpu_map,
Mike Travis7c16ec52008-04-04 18:11:11 -07007265 &cpu_to_cpu_group,
7266 send_covered, tmpmask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007267 }
7268#endif
7269
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007270#ifdef CONFIG_SCHED_MC
7271 /* Set up multi-core groups */
7272 for_each_cpu_mask(i, *cpu_map) {
Mike Travis7c16ec52008-04-04 18:11:11 -07007273 SCHED_CPUMASK_VAR(this_core_map, allmasks);
7274 SCHED_CPUMASK_VAR(send_covered, allmasks);
7275
7276 *this_core_map = cpu_coregroup_map(i);
7277 cpus_and(*this_core_map, *this_core_map, *cpu_map);
7278 if (i != first_cpu(*this_core_map))
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007279 continue;
Mike Travis7c16ec52008-04-04 18:11:11 -07007280
Ingo Molnardd41f592007-07-09 18:51:59 +02007281 init_sched_build_groups(this_core_map, cpu_map,
Mike Travis7c16ec52008-04-04 18:11:11 -07007282 &cpu_to_core_group,
7283 send_covered, tmpmask);
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007284 }
7285#endif
7286
Linus Torvalds1da177e2005-04-16 15:20:36 -07007287 /* Set up physical groups */
7288 for (i = 0; i < MAX_NUMNODES; i++) {
Mike Travis7c16ec52008-04-04 18:11:11 -07007289 SCHED_CPUMASK_VAR(nodemask, allmasks);
7290 SCHED_CPUMASK_VAR(send_covered, allmasks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007291
Mike Travis7c16ec52008-04-04 18:11:11 -07007292 *nodemask = node_to_cpumask(i);
7293 cpus_and(*nodemask, *nodemask, *cpu_map);
7294 if (cpus_empty(*nodemask))
Linus Torvalds1da177e2005-04-16 15:20:36 -07007295 continue;
7296
Mike Travis7c16ec52008-04-04 18:11:11 -07007297 init_sched_build_groups(nodemask, cpu_map,
7298 &cpu_to_phys_group,
7299 send_covered, tmpmask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007300 }
7301
7302#ifdef CONFIG_NUMA
7303 /* Set up node groups */
Mike Travis7c16ec52008-04-04 18:11:11 -07007304 if (sd_allnodes) {
7305 SCHED_CPUMASK_VAR(send_covered, allmasks);
7306
7307 init_sched_build_groups(cpu_map, cpu_map,
7308 &cpu_to_allnodes_group,
7309 send_covered, tmpmask);
7310 }
John Hawkes9c1cfda2005-09-06 15:18:14 -07007311
7312 for (i = 0; i < MAX_NUMNODES; i++) {
7313 /* Set up node groups */
7314 struct sched_group *sg, *prev;
Mike Travis7c16ec52008-04-04 18:11:11 -07007315 SCHED_CPUMASK_VAR(nodemask, allmasks);
7316 SCHED_CPUMASK_VAR(domainspan, allmasks);
7317 SCHED_CPUMASK_VAR(covered, allmasks);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007318 int j;
7319
Mike Travis7c16ec52008-04-04 18:11:11 -07007320 *nodemask = node_to_cpumask(i);
7321 cpus_clear(*covered);
7322
7323 cpus_and(*nodemask, *nodemask, *cpu_map);
7324 if (cpus_empty(*nodemask)) {
John Hawkesd1b55132005-09-06 15:18:14 -07007325 sched_group_nodes[i] = NULL;
John Hawkes9c1cfda2005-09-06 15:18:14 -07007326 continue;
John Hawkesd1b55132005-09-06 15:18:14 -07007327 }
John Hawkes9c1cfda2005-09-06 15:18:14 -07007328
Mike Travis4bdbaad32008-04-15 16:35:52 -07007329 sched_domain_node_span(i, domainspan);
Mike Travis7c16ec52008-04-04 18:11:11 -07007330 cpus_and(*domainspan, *domainspan, *cpu_map);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007331
Srivatsa Vaddagiri15f0b672006-06-27 02:54:40 -07007332 sg = kmalloc_node(sizeof(struct sched_group), GFP_KERNEL, i);
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007333 if (!sg) {
7334 printk(KERN_WARNING "Can not alloc domain group for "
7335 "node %d\n", i);
7336 goto error;
7337 }
John Hawkes9c1cfda2005-09-06 15:18:14 -07007338 sched_group_nodes[i] = sg;
Mike Travis7c16ec52008-04-04 18:11:11 -07007339 for_each_cpu_mask(j, *nodemask) {
John Hawkes9c1cfda2005-09-06 15:18:14 -07007340 struct sched_domain *sd;
Ingo Molnar9761eea2007-07-09 18:52:00 +02007341
John Hawkes9c1cfda2005-09-06 15:18:14 -07007342 sd = &per_cpu(node_domains, j);
7343 sd->groups = sg;
John Hawkes9c1cfda2005-09-06 15:18:14 -07007344 }
Eric Dumazet5517d862007-05-08 00:32:57 -07007345 sg->__cpu_power = 0;
Mike Travis7c16ec52008-04-04 18:11:11 -07007346 sg->cpumask = *nodemask;
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007347 sg->next = sg;
Mike Travis7c16ec52008-04-04 18:11:11 -07007348 cpus_or(*covered, *covered, *nodemask);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007349 prev = sg;
7350
7351 for (j = 0; j < MAX_NUMNODES; j++) {
Mike Travis7c16ec52008-04-04 18:11:11 -07007352 SCHED_CPUMASK_VAR(notcovered, allmasks);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007353 int n = (i + j) % MAX_NUMNODES;
Mike Travisc5f59f02008-04-04 18:11:10 -07007354 node_to_cpumask_ptr(pnodemask, n);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007355
Mike Travis7c16ec52008-04-04 18:11:11 -07007356 cpus_complement(*notcovered, *covered);
7357 cpus_and(*tmpmask, *notcovered, *cpu_map);
7358 cpus_and(*tmpmask, *tmpmask, *domainspan);
7359 if (cpus_empty(*tmpmask))
John Hawkes9c1cfda2005-09-06 15:18:14 -07007360 break;
7361
Mike Travis7c16ec52008-04-04 18:11:11 -07007362 cpus_and(*tmpmask, *tmpmask, *pnodemask);
7363 if (cpus_empty(*tmpmask))
John Hawkes9c1cfda2005-09-06 15:18:14 -07007364 continue;
7365
Srivatsa Vaddagiri15f0b672006-06-27 02:54:40 -07007366 sg = kmalloc_node(sizeof(struct sched_group),
7367 GFP_KERNEL, i);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007368 if (!sg) {
7369 printk(KERN_WARNING
7370 "Can not alloc domain group for node %d\n", j);
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007371 goto error;
John Hawkes9c1cfda2005-09-06 15:18:14 -07007372 }
Eric Dumazet5517d862007-05-08 00:32:57 -07007373 sg->__cpu_power = 0;
Mike Travis7c16ec52008-04-04 18:11:11 -07007374 sg->cpumask = *tmpmask;
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007375 sg->next = prev->next;
Mike Travis7c16ec52008-04-04 18:11:11 -07007376 cpus_or(*covered, *covered, *tmpmask);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007377 prev->next = sg;
7378 prev = sg;
7379 }
John Hawkes9c1cfda2005-09-06 15:18:14 -07007380 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07007381#endif
7382
7383 /* Calculate CPU power for physical packages and nodes */
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007384#ifdef CONFIG_SCHED_SMT
7385 for_each_cpu_mask(i, *cpu_map) {
Ingo Molnardd41f592007-07-09 18:51:59 +02007386 struct sched_domain *sd = &per_cpu(cpu_domains, i);
7387
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007388 init_sched_groups_power(i, sd);
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007389 }
7390#endif
7391#ifdef CONFIG_SCHED_MC
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007392 for_each_cpu_mask(i, *cpu_map) {
Ingo Molnardd41f592007-07-09 18:51:59 +02007393 struct sched_domain *sd = &per_cpu(core_domains, i);
7394
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007395 init_sched_groups_power(i, sd);
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007396 }
7397#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07007398
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007399 for_each_cpu_mask(i, *cpu_map) {
Ingo Molnardd41f592007-07-09 18:51:59 +02007400 struct sched_domain *sd = &per_cpu(phys_domains, i);
7401
Siddha, Suresh B89c47102006-10-03 01:14:09 -07007402 init_sched_groups_power(i, sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007403 }
7404
John Hawkes9c1cfda2005-09-06 15:18:14 -07007405#ifdef CONFIG_NUMA
Siddha, Suresh B08069032006-03-27 01:15:23 -08007406 for (i = 0; i < MAX_NUMNODES; i++)
7407 init_numa_sched_groups_power(sched_group_nodes[i]);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007408
Siddha, Suresh B6711cab2006-12-10 02:20:07 -08007409 if (sd_allnodes) {
7410 struct sched_group *sg;
Siddha, Suresh Bf712c0c2006-07-30 03:02:59 -07007411
Mike Travis7c16ec52008-04-04 18:11:11 -07007412 cpu_to_allnodes_group(first_cpu(*cpu_map), cpu_map, &sg,
7413 tmpmask);
Siddha, Suresh Bf712c0c2006-07-30 03:02:59 -07007414 init_numa_sched_groups_power(sg);
7415 }
John Hawkes9c1cfda2005-09-06 15:18:14 -07007416#endif
7417
Linus Torvalds1da177e2005-04-16 15:20:36 -07007418 /* Attach the domains */
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007419 for_each_cpu_mask(i, *cpu_map) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07007420 struct sched_domain *sd;
7421#ifdef CONFIG_SCHED_SMT
7422 sd = &per_cpu(cpu_domains, i);
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -08007423#elif defined(CONFIG_SCHED_MC)
7424 sd = &per_cpu(core_domains, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007425#else
7426 sd = &per_cpu(phys_domains, i);
7427#endif
Gregory Haskins57d885f2008-01-25 21:08:18 +01007428 cpu_attach_domain(sd, rd, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07007429 }
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007430
Mike Travis7c16ec52008-04-04 18:11:11 -07007431 SCHED_CPUMASK_FREE((void *)allmasks);
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007432 return 0;
7433
Siddha, Suresh Ba6160582006-10-03 01:14:06 -07007434#ifdef CONFIG_NUMA
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007435error:
Mike Travis7c16ec52008-04-04 18:11:11 -07007436 free_sched_groups(cpu_map, tmpmask);
7437 SCHED_CPUMASK_FREE((void *)allmasks);
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007438 return -ENOMEM;
Siddha, Suresh Ba6160582006-10-03 01:14:06 -07007439#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07007440}
Paul Jackson029190c2007-10-18 23:40:20 -07007441
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007442static int build_sched_domains(const cpumask_t *cpu_map)
7443{
7444 return __build_sched_domains(cpu_map, NULL);
7445}
7446
Paul Jackson029190c2007-10-18 23:40:20 -07007447static cpumask_t *doms_cur; /* current sched domains */
7448static int ndoms_cur; /* number of sched domains in 'doms_cur' */
Ingo Molnar4285f5942008-05-16 17:47:14 +02007449static struct sched_domain_attr *dattr_cur;
7450 /* attribues of custom domains in 'doms_cur' */
Paul Jackson029190c2007-10-18 23:40:20 -07007451
7452/*
7453 * Special case: If a kmalloc of a doms_cur partition (array of
7454 * cpumask_t) fails, then fallback to a single sched domain,
7455 * as determined by the single cpumask_t fallback_doms.
7456 */
7457static cpumask_t fallback_doms;
7458
Heiko Carstens22e52b02008-03-12 18:31:59 +01007459void __attribute__((weak)) arch_update_cpu_topology(void)
7460{
7461}
7462
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007463/*
Max Krasnyansky5c8e1ed2008-05-29 11:17:01 -07007464 * Free current domain masks.
7465 * Called after all cpus are attached to NULL domain.
7466 */
7467static void free_sched_domains(void)
7468{
7469 ndoms_cur = 0;
7470 if (doms_cur != &fallback_doms)
7471 kfree(doms_cur);
7472 doms_cur = &fallback_doms;
7473}
7474
7475/*
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01007476 * Set up scheduler domains and groups. Callers must hold the hotplug lock.
Paul Jackson029190c2007-10-18 23:40:20 -07007477 * For now this just excludes isolated cpus, but could be used to
7478 * exclude other special cases in the future.
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007479 */
Srivatsa Vaddagiri51888ca2006-06-27 02:54:38 -07007480static int arch_init_sched_domains(const cpumask_t *cpu_map)
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007481{
Milton Miller73785472007-10-24 18:23:48 +02007482 int err;
7483
Heiko Carstens22e52b02008-03-12 18:31:59 +01007484 arch_update_cpu_topology();
Paul Jackson029190c2007-10-18 23:40:20 -07007485 ndoms_cur = 1;
7486 doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
7487 if (!doms_cur)
7488 doms_cur = &fallback_doms;
7489 cpus_andnot(*doms_cur, *cpu_map, cpu_isolated_map);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007490 dattr_cur = NULL;
Milton Miller73785472007-10-24 18:23:48 +02007491 err = build_sched_domains(doms_cur);
Milton Miller6382bc92007-10-15 17:00:19 +02007492 register_sched_domain_sysctl();
Milton Miller73785472007-10-24 18:23:48 +02007493
7494 return err;
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007495}
7496
Mike Travis7c16ec52008-04-04 18:11:11 -07007497static void arch_destroy_sched_domains(const cpumask_t *cpu_map,
7498 cpumask_t *tmpmask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07007499{
Mike Travis7c16ec52008-04-04 18:11:11 -07007500 free_sched_groups(cpu_map, tmpmask);
John Hawkes9c1cfda2005-09-06 15:18:14 -07007501}
Linus Torvalds1da177e2005-04-16 15:20:36 -07007502
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007503/*
7504 * Detach sched domains from a group of cpus specified in cpu_map
7505 * These cpus will now be attached to the NULL domain
7506 */
Arjan van de Ven858119e2006-01-14 13:20:43 -08007507static void detach_destroy_domains(const cpumask_t *cpu_map)
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007508{
Mike Travis7c16ec52008-04-04 18:11:11 -07007509 cpumask_t tmpmask;
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007510 int i;
7511
Milton Miller6382bc92007-10-15 17:00:19 +02007512 unregister_sched_domain_sysctl();
7513
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007514 for_each_cpu_mask(i, *cpu_map)
Gregory Haskins57d885f2008-01-25 21:08:18 +01007515 cpu_attach_domain(NULL, &def_root_domain, i);
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007516 synchronize_sched();
Mike Travis7c16ec52008-04-04 18:11:11 -07007517 arch_destroy_sched_domains(cpu_map, &tmpmask);
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007518}
7519
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007520/* handle null as "default" */
7521static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
7522 struct sched_domain_attr *new, int idx_new)
7523{
7524 struct sched_domain_attr tmp;
7525
7526 /* fast path */
7527 if (!new && !cur)
7528 return 1;
7529
7530 tmp = SD_ATTR_INIT;
7531 return !memcmp(cur ? (cur + idx_cur) : &tmp,
7532 new ? (new + idx_new) : &tmp,
7533 sizeof(struct sched_domain_attr));
7534}
7535
Paul Jackson029190c2007-10-18 23:40:20 -07007536/*
7537 * Partition sched domains as specified by the 'ndoms_new'
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01007538 * cpumasks in the array doms_new[] of cpumasks. This compares
Paul Jackson029190c2007-10-18 23:40:20 -07007539 * doms_new[] to the current sched domain partitioning, doms_cur[].
7540 * It destroys each deleted domain and builds each new domain.
7541 *
7542 * 'doms_new' is an array of cpumask_t's of length 'ndoms_new'.
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01007543 * The masks don't intersect (don't overlap.) We should setup one
7544 * sched domain for each mask. CPUs not in any of the cpumasks will
7545 * not be load balanced. If the same cpumask appears both in the
Paul Jackson029190c2007-10-18 23:40:20 -07007546 * current 'doms_cur' domains and in the new 'doms_new', we can leave
7547 * it as it is.
7548 *
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01007549 * The passed in 'doms_new' should be kmalloc'd. This routine takes
7550 * ownership of it and will kfree it when done with it. If the caller
Paul Jackson029190c2007-10-18 23:40:20 -07007551 * failed the kmalloc call, then it can pass in doms_new == NULL,
7552 * and partition_sched_domains() will fallback to the single partition
7553 * 'fallback_doms'.
7554 *
7555 * Call with hotplug lock held
7556 */
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007557void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
7558 struct sched_domain_attr *dattr_new)
Paul Jackson029190c2007-10-18 23:40:20 -07007559{
7560 int i, j;
7561
Heiko Carstens712555e2008-04-28 11:33:07 +02007562 mutex_lock(&sched_domains_mutex);
Srivatsa Vaddagiria1835612008-01-25 21:08:00 +01007563
Milton Miller73785472007-10-24 18:23:48 +02007564 /* always unregister in case we don't destroy any domains */
7565 unregister_sched_domain_sysctl();
7566
Paul Jackson029190c2007-10-18 23:40:20 -07007567 if (doms_new == NULL) {
7568 ndoms_new = 1;
7569 doms_new = &fallback_doms;
7570 cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007571 dattr_new = NULL;
Paul Jackson029190c2007-10-18 23:40:20 -07007572 }
7573
7574 /* Destroy deleted domains */
7575 for (i = 0; i < ndoms_cur; i++) {
7576 for (j = 0; j < ndoms_new; j++) {
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007577 if (cpus_equal(doms_cur[i], doms_new[j])
7578 && dattrs_equal(dattr_cur, i, dattr_new, j))
Paul Jackson029190c2007-10-18 23:40:20 -07007579 goto match1;
7580 }
7581 /* no match - a current sched domain not in new doms_new[] */
7582 detach_destroy_domains(doms_cur + i);
7583match1:
7584 ;
7585 }
7586
7587 /* Build new domains */
7588 for (i = 0; i < ndoms_new; i++) {
7589 for (j = 0; j < ndoms_cur; j++) {
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007590 if (cpus_equal(doms_new[i], doms_cur[j])
7591 && dattrs_equal(dattr_new, i, dattr_cur, j))
Paul Jackson029190c2007-10-18 23:40:20 -07007592 goto match2;
7593 }
7594 /* no match - add a new doms_new */
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007595 __build_sched_domains(doms_new + i,
7596 dattr_new ? dattr_new + i : NULL);
Paul Jackson029190c2007-10-18 23:40:20 -07007597match2:
7598 ;
7599 }
7600
7601 /* Remember the new sched domains */
7602 if (doms_cur != &fallback_doms)
7603 kfree(doms_cur);
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007604 kfree(dattr_cur); /* kfree(NULL) is safe */
Paul Jackson029190c2007-10-18 23:40:20 -07007605 doms_cur = doms_new;
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +09007606 dattr_cur = dattr_new;
Paul Jackson029190c2007-10-18 23:40:20 -07007607 ndoms_cur = ndoms_new;
Milton Miller73785472007-10-24 18:23:48 +02007608
7609 register_sched_domain_sysctl();
Srivatsa Vaddagiria1835612008-01-25 21:08:00 +01007610
Heiko Carstens712555e2008-04-28 11:33:07 +02007611 mutex_unlock(&sched_domains_mutex);
Paul Jackson029190c2007-10-18 23:40:20 -07007612}
7613
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007614#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
Heiko Carstens9aefd0a2008-03-12 18:31:58 +01007615int arch_reinit_sched_domains(void)
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007616{
7617 int err;
7618
Gautham R Shenoy95402b32008-01-25 21:08:02 +01007619 get_online_cpus();
Heiko Carstens712555e2008-04-28 11:33:07 +02007620 mutex_lock(&sched_domains_mutex);
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007621 detach_destroy_domains(&cpu_online_map);
Max Krasnyansky5c8e1ed2008-05-29 11:17:01 -07007622 free_sched_domains();
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007623 err = arch_init_sched_domains(&cpu_online_map);
Heiko Carstens712555e2008-04-28 11:33:07 +02007624 mutex_unlock(&sched_domains_mutex);
Gautham R Shenoy95402b32008-01-25 21:08:02 +01007625 put_online_cpus();
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007626
7627 return err;
7628}
7629
7630static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
7631{
7632 int ret;
7633
7634 if (buf[0] != '0' && buf[0] != '1')
7635 return -EINVAL;
7636
7637 if (smt)
7638 sched_smt_power_savings = (buf[0] == '1');
7639 else
7640 sched_mc_power_savings = (buf[0] == '1');
7641
7642 ret = arch_reinit_sched_domains();
7643
7644 return ret ? ret : count;
7645}
7646
Adrian Bunk6707de002007-08-12 18:08:19 +02007647#ifdef CONFIG_SCHED_MC
7648static ssize_t sched_mc_power_savings_show(struct sys_device *dev, char *page)
7649{
7650 return sprintf(page, "%u\n", sched_mc_power_savings);
7651}
7652static ssize_t sched_mc_power_savings_store(struct sys_device *dev,
7653 const char *buf, size_t count)
7654{
7655 return sched_power_savings_store(buf, count, 0);
7656}
7657static SYSDEV_ATTR(sched_mc_power_savings, 0644, sched_mc_power_savings_show,
7658 sched_mc_power_savings_store);
7659#endif
7660
7661#ifdef CONFIG_SCHED_SMT
7662static ssize_t sched_smt_power_savings_show(struct sys_device *dev, char *page)
7663{
7664 return sprintf(page, "%u\n", sched_smt_power_savings);
7665}
7666static ssize_t sched_smt_power_savings_store(struct sys_device *dev,
7667 const char *buf, size_t count)
7668{
7669 return sched_power_savings_store(buf, count, 1);
7670}
7671static SYSDEV_ATTR(sched_smt_power_savings, 0644, sched_smt_power_savings_show,
7672 sched_smt_power_savings_store);
7673#endif
7674
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007675int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
7676{
7677 int err = 0;
Ingo Molnar48f24c42006-07-03 00:25:40 -07007678
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007679#ifdef CONFIG_SCHED_SMT
7680 if (smt_capable())
7681 err = sysfs_create_file(&cls->kset.kobj,
7682 &attr_sched_smt_power_savings.attr);
7683#endif
7684#ifdef CONFIG_SCHED_MC
7685 if (!err && mc_capable())
7686 err = sysfs_create_file(&cls->kset.kobj,
7687 &attr_sched_mc_power_savings.attr);
7688#endif
7689 return err;
7690}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02007691#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07007692
Linus Torvalds1da177e2005-04-16 15:20:36 -07007693/*
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01007694 * Force a reinitialization of the sched domains hierarchy. The domains
Linus Torvalds1da177e2005-04-16 15:20:36 -07007695 * and groups cannot be updated in place without racing with the balancing
Nick Piggin41c7ce92005-06-25 14:57:24 -07007696 * code, so we temporarily attach all running cpus to the NULL domain
Linus Torvalds1da177e2005-04-16 15:20:36 -07007697 * which will prevent rebalancing while the sched domains are recalculated.
7698 */
7699static int update_sched_domains(struct notifier_block *nfb,
7700 unsigned long action, void *hcpu)
7701{
Peter Zijlstra7def2be2008-06-05 14:49:58 +02007702 int cpu = (int)(long)hcpu;
7703
Linus Torvalds1da177e2005-04-16 15:20:36 -07007704 switch (action) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07007705 case CPU_DOWN_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07007706 case CPU_DOWN_PREPARE_FROZEN:
Peter Zijlstra7def2be2008-06-05 14:49:58 +02007707 disable_runtime(cpu_rq(cpu));
7708 /* fall-through */
7709 case CPU_UP_PREPARE:
7710 case CPU_UP_PREPARE_FROZEN:
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007711 detach_destroy_domains(&cpu_online_map);
Max Krasnyansky5c8e1ed2008-05-29 11:17:01 -07007712 free_sched_domains();
Linus Torvalds1da177e2005-04-16 15:20:36 -07007713 return NOTIFY_OK;
7714
Peter Zijlstra7def2be2008-06-05 14:49:58 +02007715
Linus Torvalds1da177e2005-04-16 15:20:36 -07007716 case CPU_DOWN_FAILED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07007717 case CPU_DOWN_FAILED_FROZEN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07007718 case CPU_ONLINE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07007719 case CPU_ONLINE_FROZEN:
Peter Zijlstra7def2be2008-06-05 14:49:58 +02007720 enable_runtime(cpu_rq(cpu));
7721 /* fall-through */
7722 case CPU_UP_CANCELED:
7723 case CPU_UP_CANCELED_FROZEN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07007724 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07007725 case CPU_DEAD_FROZEN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07007726 /*
7727 * Fall through and re-initialise the domains.
7728 */
7729 break;
7730 default:
7731 return NOTIFY_DONE;
7732 }
7733
Max Krasnyansky5c8e1ed2008-05-29 11:17:01 -07007734#ifndef CONFIG_CPUSETS
7735 /*
7736 * Create default domain partitioning if cpusets are disabled.
7737 * Otherwise we let cpusets rebuild the domains based on the
7738 * current setup.
7739 */
7740
Linus Torvalds1da177e2005-04-16 15:20:36 -07007741 /* The hotplug lock is already held by cpu_up/cpu_down */
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007742 arch_init_sched_domains(&cpu_online_map);
Max Krasnyansky5c8e1ed2008-05-29 11:17:01 -07007743#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07007744
7745 return NOTIFY_OK;
7746}
Linus Torvalds1da177e2005-04-16 15:20:36 -07007747
7748void __init sched_init_smp(void)
7749{
Nick Piggin5c1e1762006-10-03 01:14:04 -07007750 cpumask_t non_isolated_cpus;
7751
Mike Travis434d53b2008-04-04 18:11:04 -07007752#if defined(CONFIG_NUMA)
7753 sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
7754 GFP_KERNEL);
7755 BUG_ON(sched_group_nodes_bycpu == NULL);
7756#endif
Gautham R Shenoy95402b32008-01-25 21:08:02 +01007757 get_online_cpus();
Heiko Carstens712555e2008-04-28 11:33:07 +02007758 mutex_lock(&sched_domains_mutex);
Dinakar Guniguntala1a20ff22005-06-25 14:57:33 -07007759 arch_init_sched_domains(&cpu_online_map);
Nathan Lynche5e56732007-01-10 23:15:28 -08007760 cpus_andnot(non_isolated_cpus, cpu_possible_map, cpu_isolated_map);
Nick Piggin5c1e1762006-10-03 01:14:04 -07007761 if (cpus_empty(non_isolated_cpus))
7762 cpu_set(smp_processor_id(), non_isolated_cpus);
Heiko Carstens712555e2008-04-28 11:33:07 +02007763 mutex_unlock(&sched_domains_mutex);
Gautham R Shenoy95402b32008-01-25 21:08:02 +01007764 put_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -07007765 /* XXX: Theoretical race here - CPU may be hotplugged now */
7766 hotcpu_notifier(update_sched_domains, 0);
Peter Zijlstrab328ca12008-04-29 10:02:46 +02007767 init_hrtick();
Nick Piggin5c1e1762006-10-03 01:14:04 -07007768
7769 /* Move init over to a non-isolated CPU */
Mike Travis7c16ec52008-04-04 18:11:11 -07007770 if (set_cpus_allowed_ptr(current, &non_isolated_cpus) < 0)
Nick Piggin5c1e1762006-10-03 01:14:04 -07007771 BUG();
Ingo Molnar19978ca2007-11-09 22:39:38 +01007772 sched_init_granularity();
Linus Torvalds1da177e2005-04-16 15:20:36 -07007773}
7774#else
7775void __init sched_init_smp(void)
7776{
Ingo Molnar19978ca2007-11-09 22:39:38 +01007777 sched_init_granularity();
Linus Torvalds1da177e2005-04-16 15:20:36 -07007778}
7779#endif /* CONFIG_SMP */
7780
7781int in_sched_functions(unsigned long addr)
7782{
Linus Torvalds1da177e2005-04-16 15:20:36 -07007783 return in_lock_functions(addr) ||
7784 (addr >= (unsigned long)__sched_text_start
7785 && addr < (unsigned long)__sched_text_end);
7786}
7787
Alexey Dobriyana9957442007-10-15 17:00:13 +02007788static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
Ingo Molnardd41f592007-07-09 18:51:59 +02007789{
7790 cfs_rq->tasks_timeline = RB_ROOT;
Peter Zijlstra4a55bd52008-04-19 19:45:00 +02007791 INIT_LIST_HEAD(&cfs_rq->tasks);
Ingo Molnardd41f592007-07-09 18:51:59 +02007792#ifdef CONFIG_FAIR_GROUP_SCHED
7793 cfs_rq->rq = rq;
7794#endif
Peter Zijlstra67e9fb22007-10-15 17:00:10 +02007795 cfs_rq->min_vruntime = (u64)(-(1LL << 20));
Ingo Molnardd41f592007-07-09 18:51:59 +02007796}
7797
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01007798static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
7799{
7800 struct rt_prio_array *array;
7801 int i;
7802
7803 array = &rt_rq->active;
7804 for (i = 0; i < MAX_RT_PRIO; i++) {
Dmitry Adamushko20b63312008-06-11 00:58:30 +02007805 INIT_LIST_HEAD(array->queue + i);
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01007806 __clear_bit(i, array->bitmap);
7807 }
7808 /* delimiter for bitsearch: */
7809 __set_bit(MAX_RT_PRIO, array->bitmap);
7810
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01007811#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
Peter Zijlstra48d5e252008-01-25 21:08:31 +01007812 rt_rq->highest_prio = MAX_RT_PRIO;
7813#endif
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01007814#ifdef CONFIG_SMP
7815 rt_rq->rt_nr_migratory = 0;
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01007816 rt_rq->overloaded = 0;
7817#endif
7818
7819 rt_rq->rt_time = 0;
7820 rt_rq->rt_throttled = 0;
Peter Zijlstraac086bc2008-04-19 19:44:58 +02007821 rt_rq->rt_runtime = 0;
7822 spin_lock_init(&rt_rq->rt_runtime_lock);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007823
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01007824#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra23b0fdf2008-02-13 15:45:39 +01007825 rt_rq->rt_nr_boosted = 0;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007826 rt_rq->rq = rq;
7827#endif
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01007828}
7829
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007830#ifdef CONFIG_FAIR_GROUP_SCHED
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007831static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
7832 struct sched_entity *se, int cpu, int add,
7833 struct sched_entity *parent)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007834{
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007835 struct rq *rq = cpu_rq(cpu);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007836 tg->cfs_rq[cpu] = cfs_rq;
7837 init_cfs_rq(cfs_rq, rq);
7838 cfs_rq->tg = tg;
7839 if (add)
7840 list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
7841
7842 tg->se[cpu] = se;
Dhaval Giani354d60c2008-04-19 19:44:59 +02007843 /* se could be NULL for init_task_group */
7844 if (!se)
7845 return;
7846
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007847 if (!parent)
7848 se->cfs_rq = &rq->cfs;
7849 else
7850 se->cfs_rq = parent->my_q;
7851
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007852 se->my_q = cfs_rq;
7853 se->load.weight = tg->shares;
Peter Zijlstrae05510d2008-05-05 23:56:17 +02007854 se->load.inv_weight = 0;
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007855 se->parent = parent;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007856}
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01007857#endif
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007858
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01007859#ifdef CONFIG_RT_GROUP_SCHED
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007860static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
7861 struct sched_rt_entity *rt_se, int cpu, int add,
7862 struct sched_rt_entity *parent)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007863{
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007864 struct rq *rq = cpu_rq(cpu);
7865
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007866 tg->rt_rq[cpu] = rt_rq;
7867 init_rt_rq(rt_rq, rq);
7868 rt_rq->tg = tg;
7869 rt_rq->rt_se = rt_se;
Peter Zijlstraac086bc2008-04-19 19:44:58 +02007870 rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007871 if (add)
7872 list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list);
7873
7874 tg->rt_se[cpu] = rt_se;
Dhaval Giani354d60c2008-04-19 19:44:59 +02007875 if (!rt_se)
7876 return;
7877
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007878 if (!parent)
7879 rt_se->rt_rq = &rq->rt;
7880 else
7881 rt_se->rt_rq = parent->my_q;
7882
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007883 rt_se->my_q = rt_rq;
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02007884 rt_se->parent = parent;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007885 INIT_LIST_HEAD(&rt_se->run_list);
7886}
7887#endif
7888
Linus Torvalds1da177e2005-04-16 15:20:36 -07007889void __init sched_init(void)
7890{
Ingo Molnardd41f592007-07-09 18:51:59 +02007891 int i, j;
Mike Travis434d53b2008-04-04 18:11:04 -07007892 unsigned long alloc_size = 0, ptr;
7893
7894#ifdef CONFIG_FAIR_GROUP_SCHED
7895 alloc_size += 2 * nr_cpu_ids * sizeof(void **);
7896#endif
7897#ifdef CONFIG_RT_GROUP_SCHED
7898 alloc_size += 2 * nr_cpu_ids * sizeof(void **);
7899#endif
Peter Zijlstraeff766a2008-04-19 19:45:00 +02007900#ifdef CONFIG_USER_SCHED
7901 alloc_size *= 2;
7902#endif
Mike Travis434d53b2008-04-04 18:11:04 -07007903 /*
7904 * As sched_init() is called before page_alloc is setup,
7905 * we use alloc_bootmem().
7906 */
7907 if (alloc_size) {
David Miller5a9d3222008-04-24 20:46:20 -07007908 ptr = (unsigned long)alloc_bootmem(alloc_size);
Mike Travis434d53b2008-04-04 18:11:04 -07007909
7910#ifdef CONFIG_FAIR_GROUP_SCHED
7911 init_task_group.se = (struct sched_entity **)ptr;
7912 ptr += nr_cpu_ids * sizeof(void **);
7913
7914 init_task_group.cfs_rq = (struct cfs_rq **)ptr;
7915 ptr += nr_cpu_ids * sizeof(void **);
Peter Zijlstraeff766a2008-04-19 19:45:00 +02007916
7917#ifdef CONFIG_USER_SCHED
7918 root_task_group.se = (struct sched_entity **)ptr;
7919 ptr += nr_cpu_ids * sizeof(void **);
7920
7921 root_task_group.cfs_rq = (struct cfs_rq **)ptr;
7922 ptr += nr_cpu_ids * sizeof(void **);
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02007923#endif /* CONFIG_USER_SCHED */
7924#endif /* CONFIG_FAIR_GROUP_SCHED */
Mike Travis434d53b2008-04-04 18:11:04 -07007925#ifdef CONFIG_RT_GROUP_SCHED
7926 init_task_group.rt_se = (struct sched_rt_entity **)ptr;
7927 ptr += nr_cpu_ids * sizeof(void **);
7928
7929 init_task_group.rt_rq = (struct rt_rq **)ptr;
Peter Zijlstraeff766a2008-04-19 19:45:00 +02007930 ptr += nr_cpu_ids * sizeof(void **);
7931
7932#ifdef CONFIG_USER_SCHED
7933 root_task_group.rt_se = (struct sched_rt_entity **)ptr;
7934 ptr += nr_cpu_ids * sizeof(void **);
7935
7936 root_task_group.rt_rq = (struct rt_rq **)ptr;
7937 ptr += nr_cpu_ids * sizeof(void **);
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02007938#endif /* CONFIG_USER_SCHED */
7939#endif /* CONFIG_RT_GROUP_SCHED */
Mike Travis434d53b2008-04-04 18:11:04 -07007940 }
Ingo Molnardd41f592007-07-09 18:51:59 +02007941
Gregory Haskins57d885f2008-01-25 21:08:18 +01007942#ifdef CONFIG_SMP
7943 init_defrootdomain();
7944#endif
7945
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02007946 init_rt_bandwidth(&def_rt_bandwidth,
7947 global_rt_period(), global_rt_runtime());
7948
7949#ifdef CONFIG_RT_GROUP_SCHED
7950 init_rt_bandwidth(&init_task_group.rt_bandwidth,
7951 global_rt_period(), global_rt_runtime());
Peter Zijlstraeff766a2008-04-19 19:45:00 +02007952#ifdef CONFIG_USER_SCHED
7953 init_rt_bandwidth(&root_task_group.rt_bandwidth,
7954 global_rt_period(), RUNTIME_INF);
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02007955#endif /* CONFIG_USER_SCHED */
7956#endif /* CONFIG_RT_GROUP_SCHED */
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02007957
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01007958#ifdef CONFIG_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007959 list_add(&init_task_group.list, &task_groups);
Peter Zijlstraf473aa52008-04-19 19:45:00 +02007960 INIT_LIST_HEAD(&init_task_group.children);
7961
7962#ifdef CONFIG_USER_SCHED
7963 INIT_LIST_HEAD(&root_task_group.children);
7964 init_task_group.parent = &root_task_group;
7965 list_add(&init_task_group.siblings, &root_task_group.children);
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02007966#endif /* CONFIG_USER_SCHED */
7967#endif /* CONFIG_GROUP_SCHED */
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007968
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08007969 for_each_possible_cpu(i) {
Ingo Molnar70b97a72006-07-03 00:25:42 -07007970 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07007971
7972 rq = cpu_rq(i);
7973 spin_lock_init(&rq->lock);
Ingo Molnarfcb99372006-07-03 00:25:10 -07007974 lockdep_set_class(&rq->lock, &rq->rq_lock_key);
Nick Piggin78979862005-06-25 14:57:13 -07007975 rq->nr_running = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02007976 init_cfs_rq(&rq->cfs, rq);
Peter Zijlstrafa85ae22008-01-25 21:08:29 +01007977 init_rt_rq(&rq->rt, rq);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01007978#ifdef CONFIG_FAIR_GROUP_SCHED
7979 init_task_group.shares = init_task_group_load;
7980 INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
Dhaval Giani354d60c2008-04-19 19:44:59 +02007981#ifdef CONFIG_CGROUP_SCHED
7982 /*
7983 * How much cpu bandwidth does init_task_group get?
7984 *
7985 * In case of task-groups formed thr' the cgroup filesystem, it
7986 * gets 100% of the cpu resources in the system. This overall
7987 * system cpu resource is divided among the tasks of
7988 * init_task_group and its child task-groups in a fair manner,
7989 * based on each entity's (task or task-group's) weight
7990 * (se->load.weight).
7991 *
7992 * In other words, if init_task_group has 10 tasks of weight
7993 * 1024) and two child groups A0 and A1 (of weight 1024 each),
7994 * then A0's share of the cpu resource is:
7995 *
7996 * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
7997 *
7998 * We achieve this by letting init_task_group's tasks sit
7999 * directly in rq->cfs (i.e init_task_group->se[] = NULL).
8000 */
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008001 init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL);
Dhaval Giani354d60c2008-04-19 19:44:59 +02008002#elif defined CONFIG_USER_SCHED
Peter Zijlstraeff766a2008-04-19 19:45:00 +02008003 root_task_group.shares = NICE_0_LOAD;
8004 init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL);
Dhaval Giani354d60c2008-04-19 19:44:59 +02008005 /*
8006 * In case of task-groups formed thr' the user id of tasks,
8007 * init_task_group represents tasks belonging to root user.
8008 * Hence it forms a sibling of all subsequent groups formed.
8009 * In this case, init_task_group gets only a fraction of overall
8010 * system cpu resource, based on the weight assigned to root
8011 * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished
8012 * by letting tasks of init_task_group sit in a separate cfs_rq
8013 * (init_cfs_rq) and having one entity represent this group of
8014 * tasks in rq->cfs (i.e init_task_group->se[] != NULL).
8015 */
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008016 init_tg_cfs_entry(&init_task_group,
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008017 &per_cpu(init_cfs_rq, i),
Peter Zijlstraeff766a2008-04-19 19:45:00 +02008018 &per_cpu(init_sched_entity, i), i, 1,
8019 root_task_group.se[i]);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008020
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008021#endif
Dhaval Giani354d60c2008-04-19 19:44:59 +02008022#endif /* CONFIG_FAIR_GROUP_SCHED */
8023
8024 rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008025#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008026 INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
Dhaval Giani354d60c2008-04-19 19:44:59 +02008027#ifdef CONFIG_CGROUP_SCHED
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008028 init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL);
Dhaval Giani354d60c2008-04-19 19:44:59 +02008029#elif defined CONFIG_USER_SCHED
Peter Zijlstraeff766a2008-04-19 19:45:00 +02008030 init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL);
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008031 init_tg_rt_entry(&init_task_group,
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008032 &per_cpu(init_rt_rq, i),
Peter Zijlstraeff766a2008-04-19 19:45:00 +02008033 &per_cpu(init_sched_rt_entity, i), i, 1,
8034 root_task_group.rt_se[i]);
Dhaval Giani354d60c2008-04-19 19:44:59 +02008035#endif
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008036#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07008037
Ingo Molnardd41f592007-07-09 18:51:59 +02008038 for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
8039 rq->cpu_load[j] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008040#ifdef CONFIG_SMP
Nick Piggin41c7ce92005-06-25 14:57:24 -07008041 rq->sd = NULL;
Gregory Haskins57d885f2008-01-25 21:08:18 +01008042 rq->rd = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008043 rq->active_balance = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02008044 rq->next_balance = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008045 rq->push_cpu = 0;
Christoph Lameter0a2966b2006-09-25 23:30:51 -07008046 rq->cpu = i;
Gregory Haskins1f11eb62008-06-04 15:04:05 -04008047 rq->online = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008048 rq->migration_thread = NULL;
8049 INIT_LIST_HEAD(&rq->migration_queue);
Gregory Haskinsdc938522008-01-25 21:08:26 +01008050 rq_attach_root(rq, &def_root_domain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008051#endif
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +01008052 init_rq_hrtick(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008053 atomic_set(&rq->nr_iowait, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008054 }
8055
Peter Williams2dd73a42006-06-27 02:54:34 -07008056 set_load_weight(&init_task);
Heiko Carstensb50f60c2006-07-30 03:03:52 -07008057
Avi Kivitye107be32007-07-26 13:40:43 +02008058#ifdef CONFIG_PREEMPT_NOTIFIERS
8059 INIT_HLIST_HEAD(&init_task.preempt_notifiers);
8060#endif
8061
Christoph Lameterc9819f42006-12-10 02:20:25 -08008062#ifdef CONFIG_SMP
8063 open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL);
8064#endif
8065
Heiko Carstensb50f60c2006-07-30 03:03:52 -07008066#ifdef CONFIG_RT_MUTEXES
8067 plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
8068#endif
8069
Linus Torvalds1da177e2005-04-16 15:20:36 -07008070 /*
8071 * The boot idle thread does lazy MMU switching as well:
8072 */
8073 atomic_inc(&init_mm.mm_count);
8074 enter_lazy_tlb(&init_mm, current);
8075
8076 /*
8077 * Make us the idle thread. Technically, schedule() should not be
8078 * called from this thread, however somewhere below it might be,
8079 * but because we are the idle thread, we just pick up running again
8080 * when this runqueue becomes "idle".
8081 */
8082 init_idle(current, smp_processor_id());
Ingo Molnardd41f592007-07-09 18:51:59 +02008083 /*
8084 * During early bootup we pretend to be a normal task:
8085 */
8086 current->sched_class = &fair_sched_class;
Ingo Molnar6892b752008-02-13 14:02:36 +01008087
8088 scheduler_running = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008089}
8090
8091#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
8092void __might_sleep(char *file, int line)
8093{
Ingo Molnar48f24c42006-07-03 00:25:40 -07008094#ifdef in_atomic
Linus Torvalds1da177e2005-04-16 15:20:36 -07008095 static unsigned long prev_jiffy; /* ratelimiting */
8096
8097 if ((in_atomic() || irqs_disabled()) &&
8098 system_state == SYSTEM_RUNNING && !oops_in_progress) {
8099 if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
8100 return;
8101 prev_jiffy = jiffies;
Ingo Molnar91368d72006-03-23 03:00:54 -08008102 printk(KERN_ERR "BUG: sleeping function called from invalid"
Linus Torvalds1da177e2005-04-16 15:20:36 -07008103 " context at %s:%d\n", file, line);
8104 printk("in_atomic():%d, irqs_disabled():%d\n",
8105 in_atomic(), irqs_disabled());
Peter Zijlstraa4c410f2006-12-06 20:37:21 -08008106 debug_show_held_locks(current);
Ingo Molnar3117df02006-12-13 00:34:43 -08008107 if (irqs_disabled())
8108 print_irqtrace_events(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008109 dump_stack();
8110 }
8111#endif
8112}
8113EXPORT_SYMBOL(__might_sleep);
8114#endif
8115
8116#ifdef CONFIG_MAGIC_SYSRQ
Andi Kleen3a5e4dc2007-10-15 17:00:15 +02008117static void normalize_task(struct rq *rq, struct task_struct *p)
8118{
8119 int on_rq;
Peter Zijlstra3e51f332008-05-03 18:29:28 +02008120
Andi Kleen3a5e4dc2007-10-15 17:00:15 +02008121 update_rq_clock(rq);
8122 on_rq = p->se.on_rq;
8123 if (on_rq)
8124 deactivate_task(rq, p, 0);
8125 __setscheduler(rq, p, SCHED_NORMAL, 0);
8126 if (on_rq) {
8127 activate_task(rq, p, 0);
8128 resched_task(rq->curr);
8129 }
8130}
8131
Linus Torvalds1da177e2005-04-16 15:20:36 -07008132void normalize_rt_tasks(void)
8133{
Ingo Molnara0f98a12007-06-17 18:37:45 +02008134 struct task_struct *g, *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008135 unsigned long flags;
Ingo Molnar70b97a72006-07-03 00:25:42 -07008136 struct rq *rq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07008137
Peter Zijlstra4cf5d772008-02-13 15:45:39 +01008138 read_lock_irqsave(&tasklist_lock, flags);
Ingo Molnara0f98a12007-06-17 18:37:45 +02008139 do_each_thread(g, p) {
Ingo Molnar178be792007-10-15 17:00:18 +02008140 /*
8141 * Only normalize user tasks:
8142 */
8143 if (!p->mm)
8144 continue;
8145
Ingo Molnardd41f592007-07-09 18:51:59 +02008146 p->se.exec_start = 0;
Ingo Molnar6cfb0d52007-08-02 17:41:40 +02008147#ifdef CONFIG_SCHEDSTATS
8148 p->se.wait_start = 0;
8149 p->se.sleep_start = 0;
Ingo Molnardd41f592007-07-09 18:51:59 +02008150 p->se.block_start = 0;
Ingo Molnar6cfb0d52007-08-02 17:41:40 +02008151#endif
Ingo Molnardd41f592007-07-09 18:51:59 +02008152
8153 if (!rt_task(p)) {
8154 /*
8155 * Renice negative nice level userspace
8156 * tasks back to 0:
8157 */
8158 if (TASK_NICE(p) < 0 && p->mm)
8159 set_user_nice(p, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008160 continue;
Ingo Molnardd41f592007-07-09 18:51:59 +02008161 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07008162
Peter Zijlstra4cf5d772008-02-13 15:45:39 +01008163 spin_lock(&p->pi_lock);
Ingo Molnarb29739f2006-06-27 02:54:51 -07008164 rq = __task_rq_lock(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008165
Ingo Molnar178be792007-10-15 17:00:18 +02008166 normalize_task(rq, p);
Andi Kleen3a5e4dc2007-10-15 17:00:15 +02008167
Ingo Molnarb29739f2006-06-27 02:54:51 -07008168 __task_rq_unlock(rq);
Peter Zijlstra4cf5d772008-02-13 15:45:39 +01008169 spin_unlock(&p->pi_lock);
Ingo Molnara0f98a12007-06-17 18:37:45 +02008170 } while_each_thread(g, p);
8171
Peter Zijlstra4cf5d772008-02-13 15:45:39 +01008172 read_unlock_irqrestore(&tasklist_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07008173}
8174
8175#endif /* CONFIG_MAGIC_SYSRQ */
Linus Torvalds1df5c102005-09-12 07:59:21 -07008176
8177#ifdef CONFIG_IA64
8178/*
8179 * These functions are only useful for the IA64 MCA handling.
8180 *
8181 * They can only be called when the whole system has been
8182 * stopped - every CPU needs to be quiescent, and no scheduling
8183 * activity can take place. Using them for anything else would
8184 * be a serious bug, and as a result, they aren't even visible
8185 * under any other configuration.
8186 */
8187
8188/**
8189 * curr_task - return the current task for a given cpu.
8190 * @cpu: the processor in question.
8191 *
8192 * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
8193 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07008194struct task_struct *curr_task(int cpu)
Linus Torvalds1df5c102005-09-12 07:59:21 -07008195{
8196 return cpu_curr(cpu);
8197}
8198
8199/**
8200 * set_curr_task - set the current task for a given cpu.
8201 * @cpu: the processor in question.
8202 * @p: the task pointer to set.
8203 *
8204 * Description: This function must only be used when non-maskable interrupts
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01008205 * are serviced on a separate stack. It allows the architecture to switch the
8206 * notion of the current task on a cpu in a non-blocking manner. This function
Linus Torvalds1df5c102005-09-12 07:59:21 -07008207 * must be called with all CPU's synchronized, and interrupts disabled, the
8208 * and caller must save the original value of the current task (see
8209 * curr_task() above) and restore that value before reenabling interrupts and
8210 * re-starting the system.
8211 *
8212 * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
8213 */
Ingo Molnar36c8b582006-07-03 00:25:41 -07008214void set_curr_task(int cpu, struct task_struct *p)
Linus Torvalds1df5c102005-09-12 07:59:21 -07008215{
8216 cpu_curr(cpu) = p;
8217}
8218
8219#endif
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008220
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008221#ifdef CONFIG_FAIR_GROUP_SCHED
8222static void free_fair_sched_group(struct task_group *tg)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008223{
8224 int i;
8225
8226 for_each_possible_cpu(i) {
8227 if (tg->cfs_rq)
8228 kfree(tg->cfs_rq[i]);
8229 if (tg->se)
8230 kfree(tg->se[i]);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008231 }
8232
8233 kfree(tg->cfs_rq);
8234 kfree(tg->se);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008235}
8236
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008237static
8238int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008239{
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008240 struct cfs_rq *cfs_rq;
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008241 struct sched_entity *se, *parent_se;
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008242 struct rq *rq;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008243 int i;
8244
Mike Travis434d53b2008-04-04 18:11:04 -07008245 tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008246 if (!tg->cfs_rq)
8247 goto err;
Mike Travis434d53b2008-04-04 18:11:04 -07008248 tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008249 if (!tg->se)
8250 goto err;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008251
8252 tg->shares = NICE_0_LOAD;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008253
8254 for_each_possible_cpu(i) {
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008255 rq = cpu_rq(i);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008256
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008257 cfs_rq = kmalloc_node(sizeof(struct cfs_rq),
8258 GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008259 if (!cfs_rq)
8260 goto err;
8261
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008262 se = kmalloc_node(sizeof(struct sched_entity),
8263 GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008264 if (!se)
8265 goto err;
8266
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008267 parent_se = parent ? parent->se[i] : NULL;
8268 init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent_se);
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008269 }
8270
8271 return 1;
8272
8273 err:
8274 return 0;
8275}
8276
8277static inline void register_fair_sched_group(struct task_group *tg, int cpu)
8278{
8279 list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list,
8280 &cpu_rq(cpu)->leaf_cfs_rq_list);
8281}
8282
8283static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
8284{
8285 list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
8286}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008287#else /* !CONFG_FAIR_GROUP_SCHED */
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008288static inline void free_fair_sched_group(struct task_group *tg)
8289{
8290}
8291
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008292static inline
8293int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008294{
8295 return 1;
8296}
8297
8298static inline void register_fair_sched_group(struct task_group *tg, int cpu)
8299{
8300}
8301
8302static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
8303{
8304}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008305#endif /* CONFIG_FAIR_GROUP_SCHED */
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008306
8307#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008308static void free_rt_sched_group(struct task_group *tg)
8309{
8310 int i;
8311
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008312 destroy_rt_bandwidth(&tg->rt_bandwidth);
8313
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008314 for_each_possible_cpu(i) {
8315 if (tg->rt_rq)
8316 kfree(tg->rt_rq[i]);
8317 if (tg->rt_se)
8318 kfree(tg->rt_se[i]);
8319 }
8320
8321 kfree(tg->rt_rq);
8322 kfree(tg->rt_se);
8323}
8324
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008325static
8326int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008327{
8328 struct rt_rq *rt_rq;
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008329 struct sched_rt_entity *rt_se, *parent_se;
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008330 struct rq *rq;
8331 int i;
8332
Mike Travis434d53b2008-04-04 18:11:04 -07008333 tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008334 if (!tg->rt_rq)
8335 goto err;
Mike Travis434d53b2008-04-04 18:11:04 -07008336 tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008337 if (!tg->rt_se)
8338 goto err;
8339
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008340 init_rt_bandwidth(&tg->rt_bandwidth,
8341 ktime_to_ns(def_rt_bandwidth.rt_period), 0);
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008342
8343 for_each_possible_cpu(i) {
8344 rq = cpu_rq(i);
8345
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008346 rt_rq = kmalloc_node(sizeof(struct rt_rq),
8347 GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
8348 if (!rt_rq)
8349 goto err;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008350
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008351 rt_se = kmalloc_node(sizeof(struct sched_rt_entity),
8352 GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
8353 if (!rt_se)
8354 goto err;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008355
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008356 parent_se = parent ? parent->rt_se[i] : NULL;
8357 init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent_se);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008358 }
8359
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008360 return 1;
8361
8362 err:
8363 return 0;
8364}
8365
8366static inline void register_rt_sched_group(struct task_group *tg, int cpu)
8367{
8368 list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list,
8369 &cpu_rq(cpu)->leaf_rt_rq_list);
8370}
8371
8372static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
8373{
8374 list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
8375}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008376#else /* !CONFIG_RT_GROUP_SCHED */
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008377static inline void free_rt_sched_group(struct task_group *tg)
8378{
8379}
8380
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008381static inline
8382int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008383{
8384 return 1;
8385}
8386
8387static inline void register_rt_sched_group(struct task_group *tg, int cpu)
8388{
8389}
8390
8391static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
8392{
8393}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008394#endif /* CONFIG_RT_GROUP_SCHED */
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008395
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008396#ifdef CONFIG_GROUP_SCHED
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008397static void free_sched_group(struct task_group *tg)
8398{
8399 free_fair_sched_group(tg);
8400 free_rt_sched_group(tg);
8401 kfree(tg);
8402}
8403
8404/* allocate runqueue etc for a new task group */
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008405struct task_group *sched_create_group(struct task_group *parent)
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008406{
8407 struct task_group *tg;
8408 unsigned long flags;
8409 int i;
8410
8411 tg = kzalloc(sizeof(*tg), GFP_KERNEL);
8412 if (!tg)
8413 return ERR_PTR(-ENOMEM);
8414
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008415 if (!alloc_fair_sched_group(tg, parent))
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008416 goto err;
8417
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008418 if (!alloc_rt_sched_group(tg, parent))
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008419 goto err;
8420
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008421 spin_lock_irqsave(&task_group_lock, flags);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008422 for_each_possible_cpu(i) {
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008423 register_fair_sched_group(tg, i);
8424 register_rt_sched_group(tg, i);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008425 }
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008426 list_add_rcu(&tg->list, &task_groups);
Peter Zijlstraf473aa52008-04-19 19:45:00 +02008427
8428 WARN_ON(!parent); /* root should already exist */
8429
8430 tg->parent = parent;
8431 list_add_rcu(&tg->siblings, &parent->children);
8432 INIT_LIST_HEAD(&tg->children);
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008433 spin_unlock_irqrestore(&task_group_lock, flags);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008434
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008435 return tg;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008436
8437err:
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008438 free_sched_group(tg);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008439 return ERR_PTR(-ENOMEM);
8440}
8441
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008442/* rcu callback to free various structures associated with a task group */
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008443static void free_sched_group_rcu(struct rcu_head *rhp)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008444{
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008445 /* now it should be safe to free those cfs_rqs */
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008446 free_sched_group(container_of(rhp, struct task_group, rcu));
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008447}
8448
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008449/* Destroy runqueue etc associated with a task group */
Ingo Molnar4cf86d72007-10-15 17:00:14 +02008450void sched_destroy_group(struct task_group *tg)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008451{
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008452 unsigned long flags;
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008453 int i;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008454
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008455 spin_lock_irqsave(&task_group_lock, flags);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008456 for_each_possible_cpu(i) {
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008457 unregister_fair_sched_group(tg, i);
8458 unregister_rt_sched_group(tg, i);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008459 }
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008460 list_del_rcu(&tg->list);
Peter Zijlstraf473aa52008-04-19 19:45:00 +02008461 list_del_rcu(&tg->siblings);
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008462 spin_unlock_irqrestore(&task_group_lock, flags);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008463
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008464 /* wait for possible concurrent references to cfs_rqs complete */
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008465 call_rcu(&tg->rcu, free_sched_group_rcu);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008466}
8467
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008468/* change task's runqueue when it moves between groups.
Ingo Molnar3a252012007-10-15 17:00:12 +02008469 * The caller of this function should have put the task in its new group
8470 * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
8471 * reflect its new group.
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008472 */
8473void sched_move_task(struct task_struct *tsk)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008474{
8475 int on_rq, running;
8476 unsigned long flags;
8477 struct rq *rq;
8478
8479 rq = task_rq_lock(tsk, &flags);
8480
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008481 update_rq_clock(rq);
8482
Dmitry Adamushko051a1d12007-12-18 15:21:13 +01008483 running = task_current(rq, tsk);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008484 on_rq = tsk->se.on_rq;
8485
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07008486 if (on_rq)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008487 dequeue_task(rq, tsk, 0);
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07008488 if (unlikely(running))
8489 tsk->sched_class->put_prev_task(rq, tsk);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008490
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008491 set_task_rq(tsk, task_cpu(tsk));
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008492
Peter Zijlstra810b3812008-02-29 15:21:01 -05008493#ifdef CONFIG_FAIR_GROUP_SCHED
8494 if (tsk->sched_class->moved_group)
8495 tsk->sched_class->moved_group(tsk);
8496#endif
8497
Hiroshi Shimamoto0e1f3482008-03-10 11:01:20 -07008498 if (unlikely(running))
8499 tsk->sched_class->set_curr_task(rq);
8500 if (on_rq)
Dmitry Adamushko7074bad2007-10-15 17:00:07 +02008501 enqueue_task(rq, tsk, 0);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008502
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008503 task_rq_unlock(rq, &flags);
8504}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008505#endif /* CONFIG_GROUP_SCHED */
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008506
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008507#ifdef CONFIG_FAIR_GROUP_SCHED
Peter Zijlstrac09595f2008-06-27 13:41:14 +02008508static void __set_se_shares(struct sched_entity *se, unsigned long shares)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008509{
8510 struct cfs_rq *cfs_rq = se->cfs_rq;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008511 int on_rq;
8512
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008513 on_rq = se->on_rq;
Peter Zijlstra62fb1852008-02-25 17:34:02 +01008514 if (on_rq)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008515 dequeue_entity(cfs_rq, se, 0);
8516
8517 se->load.weight = shares;
Peter Zijlstrae05510d2008-05-05 23:56:17 +02008518 se->load.inv_weight = 0;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008519
Peter Zijlstra62fb1852008-02-25 17:34:02 +01008520 if (on_rq)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008521 enqueue_entity(cfs_rq, se, 0);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02008522}
Peter Zijlstra62fb1852008-02-25 17:34:02 +01008523
Peter Zijlstrac09595f2008-06-27 13:41:14 +02008524static void set_se_shares(struct sched_entity *se, unsigned long shares)
8525{
8526 struct cfs_rq *cfs_rq = se->cfs_rq;
8527 struct rq *rq = cfs_rq->rq;
8528 unsigned long flags;
8529
8530 spin_lock_irqsave(&rq->lock, flags);
8531 __set_se_shares(se, shares);
8532 spin_unlock_irqrestore(&rq->lock, flags);
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008533}
8534
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008535static DEFINE_MUTEX(shares_mutex);
8536
Ingo Molnar4cf86d72007-10-15 17:00:14 +02008537int sched_group_set_shares(struct task_group *tg, unsigned long shares)
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008538{
8539 int i;
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008540 unsigned long flags;
Ingo Molnarc61935f2008-01-22 11:24:58 +01008541
Peter Zijlstra62fb1852008-02-25 17:34:02 +01008542 /*
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008543 * We can't change the weight of the root cgroup.
8544 */
8545 if (!tg->se[0])
8546 return -EINVAL;
8547
Peter Zijlstra18d95a22008-04-19 19:45:00 +02008548 if (shares < MIN_SHARES)
8549 shares = MIN_SHARES;
Miao Xiecb4ad1f2008-04-28 12:54:56 +08008550 else if (shares > MAX_SHARES)
8551 shares = MAX_SHARES;
Peter Zijlstra62fb1852008-02-25 17:34:02 +01008552
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008553 mutex_lock(&shares_mutex);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008554 if (tg->shares == shares)
Dhaval Giani5cb350b2007-10-15 17:00:14 +02008555 goto done;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008556
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008557 spin_lock_irqsave(&task_group_lock, flags);
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008558 for_each_possible_cpu(i)
8559 unregister_fair_sched_group(tg, i);
Peter Zijlstraf473aa52008-04-19 19:45:00 +02008560 list_del_rcu(&tg->siblings);
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008561 spin_unlock_irqrestore(&task_group_lock, flags);
Srivatsa Vaddagiri6b2d7702008-01-25 21:08:00 +01008562
8563 /* wait for any ongoing reference to this group to finish */
8564 synchronize_sched();
8565
8566 /*
8567 * Now we are free to modify the group's share on each cpu
8568 * w/o tripping rebalance_share or load_balance_fair.
8569 */
8570 tg->shares = shares;
Peter Zijlstrac09595f2008-06-27 13:41:14 +02008571 for_each_possible_cpu(i) {
8572 /*
8573 * force a rebalance
8574 */
8575 cfs_rq_set_shares(tg->cfs_rq[i], 0);
Miao Xiecb4ad1f2008-04-28 12:54:56 +08008576 set_se_shares(tg->se[i], shares);
Peter Zijlstrac09595f2008-06-27 13:41:14 +02008577 }
Srivatsa Vaddagiri6b2d7702008-01-25 21:08:00 +01008578
8579 /*
8580 * Enable load balance activity on this group, by inserting it back on
8581 * each cpu's rq->leaf_cfs_rq_list.
8582 */
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008583 spin_lock_irqsave(&task_group_lock, flags);
Peter Zijlstrabccbe082008-02-13 15:45:40 +01008584 for_each_possible_cpu(i)
8585 register_fair_sched_group(tg, i);
Peter Zijlstraf473aa52008-04-19 19:45:00 +02008586 list_add_rcu(&tg->siblings, &tg->parent->children);
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008587 spin_unlock_irqrestore(&task_group_lock, flags);
Dhaval Giani5cb350b2007-10-15 17:00:14 +02008588done:
Peter Zijlstra8ed36992008-02-13 15:45:39 +01008589 mutex_unlock(&shares_mutex);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02008590 return 0;
Srivatsa Vaddagiri29f59db2007-10-15 17:00:07 +02008591}
8592
Dhaval Giani5cb350b2007-10-15 17:00:14 +02008593unsigned long sched_group_shares(struct task_group *tg)
8594{
8595 return tg->shares;
8596}
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008597#endif
Dhaval Giani5cb350b2007-10-15 17:00:14 +02008598
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008599#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008600/*
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008601 * Ensure that the real time constraints are schedulable.
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008602 */
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008603static DEFINE_MUTEX(rt_constraints_mutex);
8604
8605static unsigned long to_ratio(u64 period, u64 runtime)
8606{
8607 if (runtime == RUNTIME_INF)
8608 return 1ULL << 16;
8609
Roman Zippel6f6d6a12008-05-01 04:34:28 -07008610 return div64_u64(runtime << 16, period);
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008611}
8612
Peter Zijlstrab40b2e82008-04-19 19:45:00 +02008613#ifdef CONFIG_CGROUP_SCHED
8614static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
8615{
Peter Zijlstra10b612f2008-06-19 14:22:27 +02008616 struct task_group *tgi, *parent = tg->parent;
Peter Zijlstrab40b2e82008-04-19 19:45:00 +02008617 unsigned long total = 0;
8618
8619 if (!parent) {
8620 if (global_rt_period() < period)
8621 return 0;
8622
8623 return to_ratio(period, runtime) <
8624 to_ratio(global_rt_period(), global_rt_runtime());
8625 }
8626
8627 if (ktime_to_ns(parent->rt_bandwidth.rt_period) < period)
8628 return 0;
8629
8630 rcu_read_lock();
8631 list_for_each_entry_rcu(tgi, &parent->children, siblings) {
8632 if (tgi == tg)
8633 continue;
8634
8635 total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period),
8636 tgi->rt_bandwidth.rt_runtime);
8637 }
8638 rcu_read_unlock();
8639
Peter Zijlstra10b612f2008-06-19 14:22:27 +02008640 return total + to_ratio(period, runtime) <=
Peter Zijlstrab40b2e82008-04-19 19:45:00 +02008641 to_ratio(ktime_to_ns(parent->rt_bandwidth.rt_period),
8642 parent->rt_bandwidth.rt_runtime);
8643}
8644#elif defined CONFIG_USER_SCHED
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008645static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008646{
8647 struct task_group *tgi;
8648 unsigned long total = 0;
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008649 unsigned long global_ratio =
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008650 to_ratio(global_rt_period(), global_rt_runtime());
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008651
8652 rcu_read_lock();
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008653 list_for_each_entry_rcu(tgi, &task_groups, list) {
8654 if (tgi == tg)
8655 continue;
8656
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008657 total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period),
8658 tgi->rt_bandwidth.rt_runtime);
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008659 }
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008660 rcu_read_unlock();
8661
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008662 return total + to_ratio(period, runtime) < global_ratio;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008663}
Peter Zijlstrab40b2e82008-04-19 19:45:00 +02008664#endif
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008665
Dhaval Giani521f1a242008-02-28 15:21:56 +05308666/* Must be called with tasklist_lock held */
8667static inline int tg_has_rt_tasks(struct task_group *tg)
8668{
8669 struct task_struct *g, *p;
8670 do_each_thread(g, p) {
8671 if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
8672 return 1;
8673 } while_each_thread(g, p);
8674 return 0;
8675}
8676
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008677static int tg_set_bandwidth(struct task_group *tg,
8678 u64 rt_period, u64 rt_runtime)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008679{
Peter Zijlstraac086bc2008-04-19 19:44:58 +02008680 int i, err = 0;
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008681
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008682 mutex_lock(&rt_constraints_mutex);
Dhaval Giani521f1a242008-02-28 15:21:56 +05308683 read_lock(&tasklist_lock);
Peter Zijlstraac086bc2008-04-19 19:44:58 +02008684 if (rt_runtime == 0 && tg_has_rt_tasks(tg)) {
Dhaval Giani521f1a242008-02-28 15:21:56 +05308685 err = -EBUSY;
8686 goto unlock;
8687 }
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008688 if (!__rt_schedulable(tg, rt_period, rt_runtime)) {
8689 err = -EINVAL;
8690 goto unlock;
8691 }
Peter Zijlstraac086bc2008-04-19 19:44:58 +02008692
8693 spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008694 tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
8695 tg->rt_bandwidth.rt_runtime = rt_runtime;
Peter Zijlstraac086bc2008-04-19 19:44:58 +02008696
8697 for_each_possible_cpu(i) {
8698 struct rt_rq *rt_rq = tg->rt_rq[i];
8699
8700 spin_lock(&rt_rq->rt_runtime_lock);
8701 rt_rq->rt_runtime = rt_runtime;
8702 spin_unlock(&rt_rq->rt_runtime_lock);
8703 }
8704 spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008705 unlock:
Dhaval Giani521f1a242008-02-28 15:21:56 +05308706 read_unlock(&tasklist_lock);
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008707 mutex_unlock(&rt_constraints_mutex);
8708
8709 return err;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008710}
8711
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008712int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
8713{
8714 u64 rt_runtime, rt_period;
8715
8716 rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
8717 rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
8718 if (rt_runtime_us < 0)
8719 rt_runtime = RUNTIME_INF;
8720
8721 return tg_set_bandwidth(tg, rt_period, rt_runtime);
8722}
8723
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008724long sched_group_rt_runtime(struct task_group *tg)
8725{
8726 u64 rt_runtime_us;
8727
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008728 if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF)
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008729 return -1;
8730
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008731 rt_runtime_us = tg->rt_bandwidth.rt_runtime;
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008732 do_div(rt_runtime_us, NSEC_PER_USEC);
8733 return rt_runtime_us;
8734}
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008735
8736int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
8737{
8738 u64 rt_runtime, rt_period;
8739
8740 rt_period = (u64)rt_period_us * NSEC_PER_USEC;
8741 rt_runtime = tg->rt_bandwidth.rt_runtime;
8742
8743 return tg_set_bandwidth(tg, rt_period, rt_runtime);
8744}
8745
8746long sched_group_rt_period(struct task_group *tg)
8747{
8748 u64 rt_period_us;
8749
8750 rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period);
8751 do_div(rt_period_us, NSEC_PER_USEC);
8752 return rt_period_us;
8753}
8754
8755static int sched_rt_global_constraints(void)
8756{
Peter Zijlstra10b612f2008-06-19 14:22:27 +02008757 struct task_group *tg = &root_task_group;
8758 u64 rt_runtime, rt_period;
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008759 int ret = 0;
8760
Peter Zijlstra10b612f2008-06-19 14:22:27 +02008761 rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
8762 rt_runtime = tg->rt_bandwidth.rt_runtime;
8763
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008764 mutex_lock(&rt_constraints_mutex);
Peter Zijlstra10b612f2008-06-19 14:22:27 +02008765 if (!__rt_schedulable(tg, rt_period, rt_runtime))
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008766 ret = -EINVAL;
8767 mutex_unlock(&rt_constraints_mutex);
8768
8769 return ret;
8770}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008771#else /* !CONFIG_RT_GROUP_SCHED */
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008772static int sched_rt_global_constraints(void)
8773{
Peter Zijlstraac086bc2008-04-19 19:44:58 +02008774 unsigned long flags;
8775 int i;
8776
8777 spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
8778 for_each_possible_cpu(i) {
8779 struct rt_rq *rt_rq = &cpu_rq(i)->rt;
8780
8781 spin_lock(&rt_rq->rt_runtime_lock);
8782 rt_rq->rt_runtime = global_rt_runtime();
8783 spin_unlock(&rt_rq->rt_runtime_lock);
8784 }
8785 spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
8786
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008787 return 0;
8788}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008789#endif /* CONFIG_RT_GROUP_SCHED */
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008790
8791int sched_rt_handler(struct ctl_table *table, int write,
8792 struct file *filp, void __user *buffer, size_t *lenp,
8793 loff_t *ppos)
8794{
8795 int ret;
8796 int old_period, old_runtime;
8797 static DEFINE_MUTEX(mutex);
8798
8799 mutex_lock(&mutex);
8800 old_period = sysctl_sched_rt_period;
8801 old_runtime = sysctl_sched_rt_runtime;
8802
8803 ret = proc_dointvec(table, write, filp, buffer, lenp, ppos);
8804
8805 if (!ret && write) {
8806 ret = sched_rt_global_constraints();
8807 if (ret) {
8808 sysctl_sched_rt_period = old_period;
8809 sysctl_sched_rt_runtime = old_runtime;
8810 } else {
8811 def_rt_bandwidth.rt_runtime = global_rt_runtime();
8812 def_rt_bandwidth.rt_period =
8813 ns_to_ktime(global_rt_period());
8814 }
8815 }
8816 mutex_unlock(&mutex);
8817
8818 return ret;
8819}
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008820
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008821#ifdef CONFIG_CGROUP_SCHED
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008822
8823/* return corresponding task_group object of a cgroup */
Paul Menage2b01dfe2007-10-24 18:23:50 +02008824static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008825{
Paul Menage2b01dfe2007-10-24 18:23:50 +02008826 return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
8827 struct task_group, css);
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008828}
8829
8830static struct cgroup_subsys_state *
Paul Menage2b01dfe2007-10-24 18:23:50 +02008831cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008832{
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008833 struct task_group *tg, *parent;
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008834
Paul Menage2b01dfe2007-10-24 18:23:50 +02008835 if (!cgrp->parent) {
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008836 /* This is early initialization for the top cgroup */
Paul Menage2b01dfe2007-10-24 18:23:50 +02008837 init_task_group.css.cgroup = cgrp;
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008838 return &init_task_group.css;
8839 }
8840
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02008841 parent = cgroup_tg(cgrp->parent);
8842 tg = sched_create_group(parent);
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008843 if (IS_ERR(tg))
8844 return ERR_PTR(-ENOMEM);
8845
8846 /* Bind the cgroup to task_group object we just created */
Paul Menage2b01dfe2007-10-24 18:23:50 +02008847 tg->css.cgroup = cgrp;
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008848
8849 return &tg->css;
8850}
8851
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01008852static void
8853cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008854{
Paul Menage2b01dfe2007-10-24 18:23:50 +02008855 struct task_group *tg = cgroup_tg(cgrp);
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008856
8857 sched_destroy_group(tg);
8858}
8859
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01008860static int
8861cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
8862 struct task_struct *tsk)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008863{
Peter Zijlstrab68aa232008-02-13 15:45:40 +01008864#ifdef CONFIG_RT_GROUP_SCHED
8865 /* Don't accept realtime tasks when there is no way for them to run */
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008866 if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0)
Peter Zijlstrab68aa232008-02-13 15:45:40 +01008867 return -EINVAL;
8868#else
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008869 /* We don't support RT-tasks being in separate groups */
8870 if (tsk->sched_class != &fair_sched_class)
8871 return -EINVAL;
Peter Zijlstrab68aa232008-02-13 15:45:40 +01008872#endif
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008873
8874 return 0;
8875}
8876
8877static void
Paul Menage2b01dfe2007-10-24 18:23:50 +02008878cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008879 struct cgroup *old_cont, struct task_struct *tsk)
8880{
8881 sched_move_task(tsk);
8882}
8883
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008884#ifdef CONFIG_FAIR_GROUP_SCHED
Paul Menagef4c753b2008-04-29 00:59:56 -07008885static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype,
Paul Menage2b01dfe2007-10-24 18:23:50 +02008886 u64 shareval)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008887{
Paul Menage2b01dfe2007-10-24 18:23:50 +02008888 return sched_group_set_shares(cgroup_tg(cgrp), shareval);
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008889}
8890
Paul Menagef4c753b2008-04-29 00:59:56 -07008891static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008892{
Paul Menage2b01dfe2007-10-24 18:23:50 +02008893 struct task_group *tg = cgroup_tg(cgrp);
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008894
8895 return (u64) tg->shares;
8896}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008897#endif /* CONFIG_FAIR_GROUP_SCHED */
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008898
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008899#ifdef CONFIG_RT_GROUP_SCHED
Mirco Tischler0c708142008-05-14 16:05:46 -07008900static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
Paul Menage06ecb272008-04-29 01:00:06 -07008901 s64 val)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008902{
Paul Menage06ecb272008-04-29 01:00:06 -07008903 return sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008904}
8905
Paul Menage06ecb272008-04-29 01:00:06 -07008906static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft)
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008907{
Paul Menage06ecb272008-04-29 01:00:06 -07008908 return sched_group_rt_runtime(cgroup_tg(cgrp));
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008909}
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008910
8911static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype,
8912 u64 rt_period_us)
8913{
8914 return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us);
8915}
8916
8917static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
8918{
8919 return sched_group_rt_period(cgroup_tg(cgrp));
8920}
Dhaval Giani6d6bc0a2008-05-30 14:23:45 +02008921#endif /* CONFIG_RT_GROUP_SCHED */
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008922
Paul Menagefe5c7cc2007-10-29 21:18:11 +01008923static struct cftype cpu_files[] = {
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008924#ifdef CONFIG_FAIR_GROUP_SCHED
Paul Menagefe5c7cc2007-10-29 21:18:11 +01008925 {
8926 .name = "shares",
Paul Menagef4c753b2008-04-29 00:59:56 -07008927 .read_u64 = cpu_shares_read_u64,
8928 .write_u64 = cpu_shares_write_u64,
Paul Menagefe5c7cc2007-10-29 21:18:11 +01008929 },
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008930#endif
8931#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008932 {
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01008933 .name = "rt_runtime_us",
Paul Menage06ecb272008-04-29 01:00:06 -07008934 .read_s64 = cpu_rt_runtime_read,
8935 .write_s64 = cpu_rt_runtime_write,
Peter Zijlstra6f505b12008-01-25 21:08:30 +01008936 },
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008937 {
8938 .name = "rt_period_us",
Paul Menagef4c753b2008-04-29 00:59:56 -07008939 .read_u64 = cpu_rt_period_read_uint,
8940 .write_u64 = cpu_rt_period_write_uint,
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02008941 },
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008942#endif
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008943};
8944
8945static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
8946{
Paul Menagefe5c7cc2007-10-29 21:18:11 +01008947 return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008948}
8949
8950struct cgroup_subsys cpu_cgroup_subsys = {
Ingo Molnar38605ca2007-10-29 21:18:11 +01008951 .name = "cpu",
8952 .create = cpu_cgroup_create,
8953 .destroy = cpu_cgroup_destroy,
8954 .can_attach = cpu_cgroup_can_attach,
8955 .attach = cpu_cgroup_attach,
8956 .populate = cpu_cgroup_populate,
8957 .subsys_id = cpu_cgroup_subsys_id,
Srivatsa Vaddagiri68318b82007-10-18 23:41:03 -07008958 .early_init = 1,
8959};
8960
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01008961#endif /* CONFIG_CGROUP_SCHED */
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01008962
8963#ifdef CONFIG_CGROUP_CPUACCT
8964
8965/*
8966 * CPU accounting code for task groups.
8967 *
8968 * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
8969 * (balbir@in.ibm.com).
8970 */
8971
8972/* track cpu usage of a group of tasks */
8973struct cpuacct {
8974 struct cgroup_subsys_state css;
8975 /* cpuusage holds pointer to a u64-type object on every cpu */
8976 u64 *cpuusage;
8977};
8978
8979struct cgroup_subsys cpuacct_subsys;
8980
8981/* return cpu accounting group corresponding to this container */
Dhaval Giani32cd7562008-02-29 10:02:43 +05308982static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01008983{
Dhaval Giani32cd7562008-02-29 10:02:43 +05308984 return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01008985 struct cpuacct, css);
8986}
8987
8988/* return cpu accounting group to which this task belongs */
8989static inline struct cpuacct *task_ca(struct task_struct *tsk)
8990{
8991 return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
8992 struct cpuacct, css);
8993}
8994
8995/* create a new cpu accounting group */
8996static struct cgroup_subsys_state *cpuacct_create(
Dhaval Giani32cd7562008-02-29 10:02:43 +05308997 struct cgroup_subsys *ss, struct cgroup *cgrp)
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01008998{
8999 struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
9000
9001 if (!ca)
9002 return ERR_PTR(-ENOMEM);
9003
9004 ca->cpuusage = alloc_percpu(u64);
9005 if (!ca->cpuusage) {
9006 kfree(ca);
9007 return ERR_PTR(-ENOMEM);
9008 }
9009
9010 return &ca->css;
9011}
9012
9013/* destroy an existing cpu accounting group */
Ingo Molnar41a2d6c2007-12-05 15:46:09 +01009014static void
Dhaval Giani32cd7562008-02-29 10:02:43 +05309015cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009016{
Dhaval Giani32cd7562008-02-29 10:02:43 +05309017 struct cpuacct *ca = cgroup_ca(cgrp);
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009018
9019 free_percpu(ca->cpuusage);
9020 kfree(ca);
9021}
9022
9023/* return total cpu usage (in nanoseconds) of a group */
Dhaval Giani32cd7562008-02-29 10:02:43 +05309024static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009025{
Dhaval Giani32cd7562008-02-29 10:02:43 +05309026 struct cpuacct *ca = cgroup_ca(cgrp);
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009027 u64 totalcpuusage = 0;
9028 int i;
9029
9030 for_each_possible_cpu(i) {
9031 u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
9032
9033 /*
9034 * Take rq->lock to make 64-bit addition safe on 32-bit
9035 * platforms.
9036 */
9037 spin_lock_irq(&cpu_rq(i)->lock);
9038 totalcpuusage += *cpuusage;
9039 spin_unlock_irq(&cpu_rq(i)->lock);
9040 }
9041
9042 return totalcpuusage;
9043}
9044
Dhaval Giani0297b802008-02-29 10:02:44 +05309045static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
9046 u64 reset)
9047{
9048 struct cpuacct *ca = cgroup_ca(cgrp);
9049 int err = 0;
9050 int i;
9051
9052 if (reset) {
9053 err = -EINVAL;
9054 goto out;
9055 }
9056
9057 for_each_possible_cpu(i) {
9058 u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
9059
9060 spin_lock_irq(&cpu_rq(i)->lock);
9061 *cpuusage = 0;
9062 spin_unlock_irq(&cpu_rq(i)->lock);
9063 }
9064out:
9065 return err;
9066}
9067
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009068static struct cftype files[] = {
9069 {
9070 .name = "usage",
Paul Menagef4c753b2008-04-29 00:59:56 -07009071 .read_u64 = cpuusage_read,
9072 .write_u64 = cpuusage_write,
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009073 },
9074};
9075
Dhaval Giani32cd7562008-02-29 10:02:43 +05309076static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009077{
Dhaval Giani32cd7562008-02-29 10:02:43 +05309078 return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files));
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +01009079}
9080
9081/*
9082 * charge this task's execution time to its accounting group.
9083 *
9084 * called with rq->lock held.
9085 */
9086static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
9087{
9088 struct cpuacct *ca;
9089
9090 if (!cpuacct_subsys.active)
9091 return;
9092
9093 ca = task_ca(tsk);
9094 if (ca) {
9095 u64 *cpuusage = percpu_ptr(ca->cpuusage, task_cpu(tsk));
9096
9097 *cpuusage += cputime;
9098 }
9099}
9100
9101struct cgroup_subsys cpuacct_subsys = {
9102 .name = "cpuacct",
9103 .create = cpuacct_create,
9104 .destroy = cpuacct_destroy,
9105 .populate = cpuacct_populate,
9106 .subsys_id = cpuacct_subsys_id,
9107};
9108#endif /* CONFIG_CGROUP_CPUACCT */