rcu: Make rcu_read_lock_sched_held() take boot time into account
[linux-2.6.git] / kernel / time / timer_list.c
1 /*
2  * kernel/time/timer_list.c
3  *
4  * List pending timers
5  *
6  * Copyright(C) 2006, 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/module.h>
15 #include <linux/spinlock.h>
16 #include <linux/sched.h>
17 #include <linux/seq_file.h>
18 #include <linux/kallsyms.h>
19 #include <linux/tick.h>
20
21 #include <asm/uaccess.h>
22
23 typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
24
25 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
26
27 /*
28  * This allows printing both to /proc/timer_list and
29  * to the console (on SysRq-Q):
30  */
31 #define SEQ_printf(m, x...)                     \
32  do {                                           \
33         if (m)                                  \
34                 seq_printf(m, x);               \
35         else                                    \
36                 printk(x);                      \
37  } while (0)
38
39 static void print_name_offset(struct seq_file *m, void *sym)
40 {
41         char symname[KSYM_NAME_LEN];
42
43         if (lookup_symbol_name((unsigned long)sym, symname) < 0)
44                 SEQ_printf(m, "<%p>", sym);
45         else
46                 SEQ_printf(m, "%s", symname);
47 }
48
49 static void
50 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
51             int idx, u64 now)
52 {
53 #ifdef CONFIG_TIMER_STATS
54         char tmp[TASK_COMM_LEN + 1];
55 #endif
56         SEQ_printf(m, " #%d: ", idx);
57         print_name_offset(m, taddr);
58         SEQ_printf(m, ", ");
59         print_name_offset(m, timer->function);
60         SEQ_printf(m, ", S:%02lx", timer->state);
61 #ifdef CONFIG_TIMER_STATS
62         SEQ_printf(m, ", ");
63         print_name_offset(m, timer->start_site);
64         memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
65         tmp[TASK_COMM_LEN] = 0;
66         SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
67 #endif
68         SEQ_printf(m, "\n");
69         SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
70                 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
71                 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
72                 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
73                 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
74 }
75
76 static void
77 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
78                     u64 now)
79 {
80         struct hrtimer *timer, tmp;
81         unsigned long next = 0, i;
82         struct rb_node *curr;
83         unsigned long flags;
84
85 next_one:
86         i = 0;
87         raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
88
89         curr = base->first;
90         /*
91          * Crude but we have to do this O(N*N) thing, because
92          * we have to unlock the base when printing:
93          */
94         while (curr && i < next) {
95                 curr = rb_next(curr);
96                 i++;
97         }
98
99         if (curr) {
100
101                 timer = rb_entry(curr, struct hrtimer, node);
102                 tmp = *timer;
103                 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
104
105                 print_timer(m, timer, &tmp, i, now);
106                 next++;
107                 goto next_one;
108         }
109         raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
110 }
111
112 static void
113 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
114 {
115         SEQ_printf(m, "  .base:       %p\n", base);
116         SEQ_printf(m, "  .index:      %d\n",
117                         base->index);
118         SEQ_printf(m, "  .resolution: %Lu nsecs\n",
119                         (unsigned long long)ktime_to_ns(base->resolution));
120         SEQ_printf(m,   "  .get_time:   ");
121         print_name_offset(m, base->get_time);
122         SEQ_printf(m,   "\n");
123 #ifdef CONFIG_HIGH_RES_TIMERS
124         SEQ_printf(m, "  .offset:     %Lu nsecs\n",
125                    (unsigned long long) ktime_to_ns(base->offset));
126 #endif
127         SEQ_printf(m,   "active timers:\n");
128         print_active_timers(m, base, now);
129 }
130
131 static void print_cpu(struct seq_file *m, int cpu, u64 now)
132 {
133         struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
134         int i;
135
136         SEQ_printf(m, "\n");
137         SEQ_printf(m, "cpu: %d\n", cpu);
138         for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
139                 SEQ_printf(m, " clock %d:\n", i);
140                 print_base(m, cpu_base->clock_base + i, now);
141         }
142 #define P(x) \
143         SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
144                    (unsigned long long)(cpu_base->x))
145 #define P_ns(x) \
146         SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
147                    (unsigned long long)(ktime_to_ns(cpu_base->x)))
148
149 #ifdef CONFIG_HIGH_RES_TIMERS
150         P_ns(expires_next);
151         P(hres_active);
152         P(nr_events);
153         P(nr_retries);
154         P(nr_hangs);
155         P_ns(max_hang_time);
156 #endif
157 #undef P
158 #undef P_ns
159
160 #ifdef CONFIG_TICK_ONESHOT
161 # define P(x) \
162         SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
163                    (unsigned long long)(ts->x))
164 # define P_ns(x) \
165         SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
166                    (unsigned long long)(ktime_to_ns(ts->x)))
167         {
168                 struct tick_sched *ts = tick_get_tick_sched(cpu);
169                 P(nohz_mode);
170                 P_ns(idle_tick);
171                 P(tick_stopped);
172                 P(idle_jiffies);
173                 P(idle_calls);
174                 P(idle_sleeps);
175                 P_ns(idle_entrytime);
176                 P_ns(idle_waketime);
177                 P_ns(idle_exittime);
178                 P_ns(idle_sleeptime);
179                 P(last_jiffies);
180                 P(next_jiffies);
181                 P_ns(idle_expires);
182                 SEQ_printf(m, "jiffies: %Lu\n",
183                            (unsigned long long)jiffies);
184         }
185 #endif
186
187 #undef P
188 #undef P_ns
189 }
190
191 #ifdef CONFIG_GENERIC_CLOCKEVENTS
192 static void
193 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
194 {
195         struct clock_event_device *dev = td->evtdev;
196
197         SEQ_printf(m, "\n");
198         SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
199         if (cpu < 0)
200                 SEQ_printf(m, "Broadcast device\n");
201         else
202                 SEQ_printf(m, "Per CPU device: %d\n", cpu);
203
204         SEQ_printf(m, "Clock Event Device: ");
205         if (!dev) {
206                 SEQ_printf(m, "<NULL>\n");
207                 return;
208         }
209         SEQ_printf(m, "%s\n", dev->name);
210         SEQ_printf(m, " max_delta_ns:   %llu\n",
211                    (unsigned long long) dev->max_delta_ns);
212         SEQ_printf(m, " min_delta_ns:   %llu\n",
213                    (unsigned long long) dev->min_delta_ns);
214         SEQ_printf(m, " mult:           %u\n", dev->mult);
215         SEQ_printf(m, " shift:          %u\n", dev->shift);
216         SEQ_printf(m, " mode:           %d\n", dev->mode);
217         SEQ_printf(m, " next_event:     %Ld nsecs\n",
218                    (unsigned long long) ktime_to_ns(dev->next_event));
219
220         SEQ_printf(m, " set_next_event: ");
221         print_name_offset(m, dev->set_next_event);
222         SEQ_printf(m, "\n");
223
224         SEQ_printf(m, " set_mode:       ");
225         print_name_offset(m, dev->set_mode);
226         SEQ_printf(m, "\n");
227
228         SEQ_printf(m, " event_handler:  ");
229         print_name_offset(m, dev->event_handler);
230         SEQ_printf(m, "\n");
231 }
232
233 static void timer_list_show_tickdevices(struct seq_file *m)
234 {
235         int cpu;
236
237 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
238         print_tickdevice(m, tick_get_broadcast_device(), -1);
239         SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
240                    cpumask_bits(tick_get_broadcast_mask())[0]);
241 #ifdef CONFIG_TICK_ONESHOT
242         SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
243                    cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
244 #endif
245         SEQ_printf(m, "\n");
246 #endif
247         for_each_online_cpu(cpu)
248                 print_tickdevice(m, tick_get_device(cpu), cpu);
249         SEQ_printf(m, "\n");
250 }
251 #else
252 static void timer_list_show_tickdevices(struct seq_file *m) { }
253 #endif
254
255 static int timer_list_show(struct seq_file *m, void *v)
256 {
257         u64 now = ktime_to_ns(ktime_get());
258         int cpu;
259
260         SEQ_printf(m, "Timer List Version: v0.5\n");
261         SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
262         SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
263
264         for_each_online_cpu(cpu)
265                 print_cpu(m, cpu, now);
266
267         SEQ_printf(m, "\n");
268         timer_list_show_tickdevices(m);
269
270         return 0;
271 }
272
273 void sysrq_timer_list_show(void)
274 {
275         timer_list_show(NULL, NULL);
276 }
277
278 static int timer_list_open(struct inode *inode, struct file *filp)
279 {
280         return single_open(filp, timer_list_show, NULL);
281 }
282
283 static const struct file_operations timer_list_fops = {
284         .open           = timer_list_open,
285         .read           = seq_read,
286         .llseek         = seq_lseek,
287         .release        = single_release,
288 };
289
290 static int __init init_timer_list_procfs(void)
291 {
292         struct proc_dir_entry *pe;
293
294         pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
295         if (!pe)
296                 return -ENOMEM;
297         return 0;
298 }
299 __initcall(init_timer_list_procfs);