[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
[linux-2.6.git] / kernel / sched_debug.c
1 /*
2  * kernel/time/sched_debug.c
3  *
4  * Print the CFS rbtree
5  *
6  * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12
13 #include <linux/proc_fs.h>
14 #include <linux/sched.h>
15 #include <linux/seq_file.h>
16 #include <linux/kallsyms.h>
17 #include <linux/utsname.h>
18
19 /*
20  * This allows printing both to /proc/sched_debug and
21  * to the console
22  */
23 #define SEQ_printf(m, x...)                     \
24  do {                                           \
25         if (m)                                  \
26                 seq_printf(m, x);               \
27         else                                    \
28                 printk(x);                      \
29  } while (0)
30
31 /*
32  * Ease the printing of nsec fields:
33  */
34 static long long nsec_high(unsigned long long nsec)
35 {
36         if ((long long)nsec < 0) {
37                 nsec = -nsec;
38                 do_div(nsec, 1000000);
39                 return -nsec;
40         }
41         do_div(nsec, 1000000);
42
43         return nsec;
44 }
45
46 static unsigned long nsec_low(unsigned long long nsec)
47 {
48         if ((long long)nsec < 0)
49                 nsec = -nsec;
50
51         return do_div(nsec, 1000000);
52 }
53
54 #define SPLIT_NS(x) nsec_high(x), nsec_low(x)
55
56 static void
57 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
58 {
59         if (rq->curr == p)
60                 SEQ_printf(m, "R");
61         else
62                 SEQ_printf(m, " ");
63
64         SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
65                 p->comm, p->pid,
66                 SPLIT_NS(p->se.vruntime),
67                 (long long)(p->nvcsw + p->nivcsw),
68                 p->prio);
69 #ifdef CONFIG_SCHEDSTATS
70         SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
71                 SPLIT_NS(p->se.vruntime),
72                 SPLIT_NS(p->se.sum_exec_runtime),
73                 SPLIT_NS(p->se.sum_sleep_runtime));
74 #else
75         SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
76                 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
77 #endif
78
79 #ifdef CONFIG_CGROUP_SCHED
80         {
81                 char path[64];
82
83                 cgroup_path(task_group(p)->css.cgroup, path, sizeof(path));
84                 SEQ_printf(m, " %s", path);
85         }
86 #endif
87         SEQ_printf(m, "\n");
88 }
89
90 static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
91 {
92         struct task_struct *g, *p;
93         unsigned long flags;
94
95         SEQ_printf(m,
96         "\nrunnable tasks:\n"
97         "            task   PID         tree-key  switches  prio"
98         "     exec-runtime         sum-exec        sum-sleep\n"
99         "------------------------------------------------------"
100         "----------------------------------------------------\n");
101
102         read_lock_irqsave(&tasklist_lock, flags);
103
104         do_each_thread(g, p) {
105                 if (!p->se.on_rq || task_cpu(p) != rq_cpu)
106                         continue;
107
108                 print_task(m, rq, p);
109         } while_each_thread(g, p);
110
111         read_unlock_irqrestore(&tasklist_lock, flags);
112 }
113
114 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
115 {
116         s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
117                 spread, rq0_min_vruntime, spread0;
118         struct rq *rq = &per_cpu(runqueues, cpu);
119         struct sched_entity *last;
120         unsigned long flags;
121
122 #if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
123         char path[128] = "";
124         struct cgroup *cgroup = NULL;
125         struct task_group *tg = cfs_rq->tg;
126
127         if (tg)
128                 cgroup = tg->css.cgroup;
129
130         if (cgroup)
131                 cgroup_path(cgroup, path, sizeof(path));
132
133         SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
134 #else
135         SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
136 #endif
137
138         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
139                         SPLIT_NS(cfs_rq->exec_clock));
140
141         spin_lock_irqsave(&rq->lock, flags);
142         if (cfs_rq->rb_leftmost)
143                 MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime;
144         last = __pick_last_entity(cfs_rq);
145         if (last)
146                 max_vruntime = last->vruntime;
147         min_vruntime = rq->cfs.min_vruntime;
148         rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime;
149         spin_unlock_irqrestore(&rq->lock, flags);
150         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
151                         SPLIT_NS(MIN_vruntime));
152         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
153                         SPLIT_NS(min_vruntime));
154         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
155                         SPLIT_NS(max_vruntime));
156         spread = max_vruntime - MIN_vruntime;
157         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
158                         SPLIT_NS(spread));
159         spread0 = min_vruntime - rq0_min_vruntime;
160         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
161                         SPLIT_NS(spread0));
162         SEQ_printf(m, "  .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
163         SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);
164 #ifdef CONFIG_SCHEDSTATS
165 #define P(n) SEQ_printf(m, "  .%-30s: %d\n", #n, rq->n);
166
167         P(yld_exp_empty);
168         P(yld_act_empty);
169         P(yld_both_empty);
170         P(yld_count);
171
172         P(sched_switch);
173         P(sched_count);
174         P(sched_goidle);
175
176         P(ttwu_count);
177         P(ttwu_local);
178
179         P(bkl_count);
180
181 #undef P
182 #endif
183         SEQ_printf(m, "  .%-30s: %ld\n", "nr_spread_over",
184                         cfs_rq->nr_spread_over);
185 #ifdef CONFIG_FAIR_GROUP_SCHED
186 #ifdef CONFIG_SMP
187         SEQ_printf(m, "  .%-30s: %lu\n", "shares", cfs_rq->shares);
188 #endif
189 #endif
190 }
191
192 void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
193 {
194 #if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
195         char path[128] = "";
196         struct cgroup *cgroup = NULL;
197         struct task_group *tg = rt_rq->tg;
198
199         if (tg)
200                 cgroup = tg->css.cgroup;
201
202         if (cgroup)
203                 cgroup_path(cgroup, path, sizeof(path));
204
205         SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path);
206 #else
207         SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
208 #endif
209
210
211 #define P(x) \
212         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
213 #define PN(x) \
214         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
215
216         P(rt_nr_running);
217         P(rt_throttled);
218         PN(rt_time);
219         PN(rt_runtime);
220
221 #undef PN
222 #undef P
223 }
224
225 static void print_cpu(struct seq_file *m, int cpu)
226 {
227         struct rq *rq = &per_cpu(runqueues, cpu);
228
229 #ifdef CONFIG_X86
230         {
231                 unsigned int freq = cpu_khz ? : 1;
232
233                 SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
234                            cpu, freq / 1000, (freq % 1000));
235         }
236 #else
237         SEQ_printf(m, "\ncpu#%d\n", cpu);
238 #endif
239
240 #define P(x) \
241         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rq->x))
242 #define PN(x) \
243         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
244
245         P(nr_running);
246         SEQ_printf(m, "  .%-30s: %lu\n", "load",
247                    rq->load.weight);
248         P(nr_switches);
249         P(nr_load_updates);
250         P(nr_uninterruptible);
251         SEQ_printf(m, "  .%-30s: %lu\n", "jiffies", jiffies);
252         PN(next_balance);
253         P(curr->pid);
254         PN(clock);
255         P(cpu_load[0]);
256         P(cpu_load[1]);
257         P(cpu_load[2]);
258         P(cpu_load[3]);
259         P(cpu_load[4]);
260 #undef P
261 #undef PN
262
263         print_cfs_stats(m, cpu);
264         print_rt_stats(m, cpu);
265
266         print_rq(m, rq, cpu);
267 }
268
269 static int sched_debug_show(struct seq_file *m, void *v)
270 {
271         u64 now = ktime_to_ns(ktime_get());
272         int cpu;
273
274         SEQ_printf(m, "Sched Debug Version: v0.07, %s %.*s\n",
275                 init_utsname()->release,
276                 (int)strcspn(init_utsname()->version, " "),
277                 init_utsname()->version);
278
279         SEQ_printf(m, "now at %Lu.%06ld msecs\n", SPLIT_NS(now));
280
281 #define P(x) \
282         SEQ_printf(m, "  .%-40s: %Ld\n", #x, (long long)(x))
283 #define PN(x) \
284         SEQ_printf(m, "  .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
285         PN(sysctl_sched_latency);
286         PN(sysctl_sched_min_granularity);
287         PN(sysctl_sched_wakeup_granularity);
288         PN(sysctl_sched_child_runs_first);
289         P(sysctl_sched_features);
290 #undef PN
291 #undef P
292
293         for_each_online_cpu(cpu)
294                 print_cpu(m, cpu);
295
296         SEQ_printf(m, "\n");
297
298         return 0;
299 }
300
301 static void sysrq_sched_debug_show(void)
302 {
303         sched_debug_show(NULL, NULL);
304 }
305
306 static int sched_debug_open(struct inode *inode, struct file *filp)
307 {
308         return single_open(filp, sched_debug_show, NULL);
309 }
310
311 static const struct file_operations sched_debug_fops = {
312         .open           = sched_debug_open,
313         .read           = seq_read,
314         .llseek         = seq_lseek,
315         .release        = single_release,
316 };
317
318 static int __init init_sched_debug_procfs(void)
319 {
320         struct proc_dir_entry *pe;
321
322         pe = proc_create("sched_debug", 0644, NULL, &sched_debug_fops);
323         if (!pe)
324                 return -ENOMEM;
325         return 0;
326 }
327
328 __initcall(init_sched_debug_procfs);
329
330 void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
331 {
332         unsigned long nr_switches;
333         unsigned long flags;
334         int num_threads = 1;
335
336         if (lock_task_sighand(p, &flags)) {
337                 num_threads = atomic_read(&p->signal->count);
338                 unlock_task_sighand(p, &flags);
339         }
340
341         SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
342         SEQ_printf(m,
343                 "---------------------------------------------------------\n");
344 #define __P(F) \
345         SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
346 #define P(F) \
347         SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
348 #define __PN(F) \
349         SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
350 #define PN(F) \
351         SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
352
353         PN(se.exec_start);
354         PN(se.vruntime);
355         PN(se.sum_exec_runtime);
356         PN(se.avg_overlap);
357
358         nr_switches = p->nvcsw + p->nivcsw;
359
360 #ifdef CONFIG_SCHEDSTATS
361         PN(se.wait_start);
362         PN(se.sleep_start);
363         PN(se.block_start);
364         PN(se.sleep_max);
365         PN(se.block_max);
366         PN(se.exec_max);
367         PN(se.slice_max);
368         PN(se.wait_max);
369         PN(se.wait_sum);
370         P(se.wait_count);
371         P(sched_info.bkl_count);
372         P(se.nr_migrations);
373         P(se.nr_migrations_cold);
374         P(se.nr_failed_migrations_affine);
375         P(se.nr_failed_migrations_running);
376         P(se.nr_failed_migrations_hot);
377         P(se.nr_forced_migrations);
378         P(se.nr_forced2_migrations);
379         P(se.nr_wakeups);
380         P(se.nr_wakeups_sync);
381         P(se.nr_wakeups_migrate);
382         P(se.nr_wakeups_local);
383         P(se.nr_wakeups_remote);
384         P(se.nr_wakeups_affine);
385         P(se.nr_wakeups_affine_attempts);
386         P(se.nr_wakeups_passive);
387         P(se.nr_wakeups_idle);
388
389         {
390                 u64 avg_atom, avg_per_cpu;
391
392                 avg_atom = p->se.sum_exec_runtime;
393                 if (nr_switches)
394                         do_div(avg_atom, nr_switches);
395                 else
396                         avg_atom = -1LL;
397
398                 avg_per_cpu = p->se.sum_exec_runtime;
399                 if (p->se.nr_migrations) {
400                         avg_per_cpu = div64_u64(avg_per_cpu,
401                                                 p->se.nr_migrations);
402                 } else {
403                         avg_per_cpu = -1LL;
404                 }
405
406                 __PN(avg_atom);
407                 __PN(avg_per_cpu);
408         }
409 #endif
410         __P(nr_switches);
411         SEQ_printf(m, "%-35s:%21Ld\n",
412                    "nr_voluntary_switches", (long long)p->nvcsw);
413         SEQ_printf(m, "%-35s:%21Ld\n",
414                    "nr_involuntary_switches", (long long)p->nivcsw);
415
416         P(se.load.weight);
417         P(policy);
418         P(prio);
419 #undef PN
420 #undef __PN
421 #undef P
422 #undef __P
423
424         {
425                 u64 t0, t1;
426
427                 t0 = sched_clock();
428                 t1 = sched_clock();
429                 SEQ_printf(m, "%-35s:%21Ld\n",
430                            "clock-delta", (long long)(t1-t0));
431         }
432 }
433
434 void proc_sched_set_task(struct task_struct *p)
435 {
436 #ifdef CONFIG_SCHEDSTATS
437         p->se.wait_max                          = 0;
438         p->se.wait_sum                          = 0;
439         p->se.wait_count                        = 0;
440         p->se.sleep_max                         = 0;
441         p->se.sum_sleep_runtime                 = 0;
442         p->se.block_max                         = 0;
443         p->se.exec_max                          = 0;
444         p->se.slice_max                         = 0;
445         p->se.nr_migrations                     = 0;
446         p->se.nr_migrations_cold                = 0;
447         p->se.nr_failed_migrations_affine       = 0;
448         p->se.nr_failed_migrations_running      = 0;
449         p->se.nr_failed_migrations_hot          = 0;
450         p->se.nr_forced_migrations              = 0;
451         p->se.nr_forced2_migrations             = 0;
452         p->se.nr_wakeups                        = 0;
453         p->se.nr_wakeups_sync                   = 0;
454         p->se.nr_wakeups_migrate                = 0;
455         p->se.nr_wakeups_local                  = 0;
456         p->se.nr_wakeups_remote                 = 0;
457         p->se.nr_wakeups_affine                 = 0;
458         p->se.nr_wakeups_affine_attempts        = 0;
459         p->se.nr_wakeups_passive                = 0;
460         p->se.nr_wakeups_idle                   = 0;
461         p->sched_info.bkl_count                 = 0;
462 #endif
463         p->se.sum_exec_runtime                  = 0;
464         p->se.prev_sum_exec_runtime             = 0;
465         p->nvcsw                                = 0;
466         p->nivcsw                               = 0;
467 }