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Ingo Molnar425e0962007-07-09 18:51:58 +02001
2#ifdef CONFIG_SCHEDSTATS
3/*
4 * bump this up when changing the output format or the meaning of an existing
5 * format, so that tools can adapt (or abort)
6 */
Luis Henriques67aa0f72009-03-24 22:10:02 +00007#define SCHEDSTAT_VERSION 15
Ingo Molnar425e0962007-07-09 18:51:58 +02008
9static int show_schedstat(struct seq_file *seq, void *v)
10{
11 int cpu;
Peter Zijlstrab9689052008-10-17 12:58:19 +020012 int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
Mike Travis39106dc2008-04-08 11:43:03 -070013 char *mask_str = kmalloc(mask_len, GFP_KERNEL);
14
15 if (mask_str == NULL)
16 return -ENOMEM;
Ingo Molnar425e0962007-07-09 18:51:58 +020017
18 seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
19 seq_printf(seq, "timestamp %lu\n", jiffies);
20 for_each_online_cpu(cpu) {
21 struct rq *rq = cpu_rq(cpu);
22#ifdef CONFIG_SMP
23 struct sched_domain *sd;
Ingo Molnar2d723762007-10-15 17:00:12 +020024 int dcount = 0;
Ingo Molnar425e0962007-07-09 18:51:58 +020025#endif
26
27 /* runqueue-specific stats */
28 seq_printf(seq,
Luis Henriques67aa0f72009-03-24 22:10:02 +000029 "cpu%d %u %u %u %u %u %u %llu %llu %lu",
30 cpu, rq->yld_count,
Ingo Molnar2d723762007-10-15 17:00:12 +020031 rq->sched_switch, rq->sched_count, rq->sched_goidle,
32 rq->ttwu_count, rq->ttwu_local,
Ken Chen9c2c4802008-12-16 23:41:22 -080033 rq->rq_cpu_time,
Ingo Molnar2d723762007-10-15 17:00:12 +020034 rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
Ingo Molnar425e0962007-07-09 18:51:58 +020035
36 seq_printf(seq, "\n");
37
38#ifdef CONFIG_SMP
39 /* domain-specific stats */
40 preempt_disable();
41 for_each_domain(cpu, sd) {
42 enum cpu_idle_type itype;
Ingo Molnar425e0962007-07-09 18:51:58 +020043
Rusty Russell758b2cd2008-11-25 02:35:04 +103044 cpumask_scnprintf(mask_str, mask_len,
Rusty Russell968ea6d2008-12-13 21:55:51 +103045 sched_domain_span(sd));
Ingo Molnar2d723762007-10-15 17:00:12 +020046 seq_printf(seq, "domain%d %s", dcount++, mask_str);
Ingo Molnar425e0962007-07-09 18:51:58 +020047 for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
48 itype++) {
Ken Chen480b9432007-10-18 21:32:56 +020049 seq_printf(seq, " %u %u %u %u %u %u %u %u",
Ingo Molnar2d723762007-10-15 17:00:12 +020050 sd->lb_count[itype],
Ingo Molnar425e0962007-07-09 18:51:58 +020051 sd->lb_balanced[itype],
52 sd->lb_failed[itype],
53 sd->lb_imbalance[itype],
54 sd->lb_gained[itype],
55 sd->lb_hot_gained[itype],
56 sd->lb_nobusyq[itype],
57 sd->lb_nobusyg[itype]);
58 }
Ingo Molnarf95e0d1c2007-11-28 15:52:56 +010059 seq_printf(seq,
60 " %u %u %u %u %u %u %u %u %u %u %u %u\n",
Ingo Molnar2d723762007-10-15 17:00:12 +020061 sd->alb_count, sd->alb_failed, sd->alb_pushed,
62 sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
63 sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
Ingo Molnar425e0962007-07-09 18:51:58 +020064 sd->ttwu_wake_remote, sd->ttwu_move_affine,
65 sd->ttwu_move_balance);
66 }
67 preempt_enable();
68#endif
69 }
Adrian Bunkc6fba542008-05-14 16:22:59 -070070 kfree(mask_str);
Ingo Molnar425e0962007-07-09 18:51:58 +020071 return 0;
72}
73
74static int schedstat_open(struct inode *inode, struct file *file)
75{
76 unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
77 char *buf = kmalloc(size, GFP_KERNEL);
78 struct seq_file *m;
79 int res;
80
81 if (!buf)
82 return -ENOMEM;
83 res = single_open(file, show_schedstat, NULL);
84 if (!res) {
85 m = file->private_data;
86 m->buf = buf;
87 m->size = size;
88 } else
89 kfree(buf);
90 return res;
91}
92
Alexey Dobriyanb5aadf72008-10-06 13:23:43 +040093static const struct file_operations proc_schedstat_operations = {
Ingo Molnar425e0962007-07-09 18:51:58 +020094 .open = schedstat_open,
95 .read = seq_read,
96 .llseek = seq_lseek,
97 .release = single_release,
98};
99
Alexey Dobriyanb5aadf72008-10-06 13:23:43 +0400100static int __init proc_schedstat_init(void)
101{
102 proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
103 return 0;
104}
105module_init(proc_schedstat_init);
106
Ingo Molnar425e0962007-07-09 18:51:58 +0200107/*
108 * Expects runqueue lock to be held for atomicity of update
109 */
110static inline void
111rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
112{
113 if (rq) {
114 rq->rq_sched_info.run_delay += delta;
Ingo Molnar2d723762007-10-15 17:00:12 +0200115 rq->rq_sched_info.pcount++;
Ingo Molnar425e0962007-07-09 18:51:58 +0200116 }
117}
118
119/*
120 * Expects runqueue lock to be held for atomicity of update
121 */
122static inline void
123rq_sched_info_depart(struct rq *rq, unsigned long long delta)
124{
125 if (rq)
Ken Chen9c2c4802008-12-16 23:41:22 -0800126 rq->rq_cpu_time += delta;
Ingo Molnar425e0962007-07-09 18:51:58 +0200127}
Ankita Garg46ac22b2008-07-01 14:30:06 +0530128
129static inline void
130rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
131{
132 if (rq)
133 rq->rq_sched_info.run_delay += delta;
134}
Ingo Molnar425e0962007-07-09 18:51:58 +0200135# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
136# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
Ingo Molnarc3c70112007-08-02 17:41:40 +0200137# define schedstat_set(var, val) do { var = (val); } while (0)
Ingo Molnar425e0962007-07-09 18:51:58 +0200138#else /* !CONFIG_SCHEDSTATS */
139static inline void
140rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
141{}
142static inline void
Ankita Garg46ac22b2008-07-01 14:30:06 +0530143rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
144{}
145static inline void
Ingo Molnar425e0962007-07-09 18:51:58 +0200146rq_sched_info_depart(struct rq *rq, unsigned long long delta)
147{}
148# define schedstat_inc(rq, field) do { } while (0)
149# define schedstat_add(rq, field, amt) do { } while (0)
Ingo Molnarc3c70112007-08-02 17:41:40 +0200150# define schedstat_set(var, val) do { } while (0)
Ingo Molnar425e0962007-07-09 18:51:58 +0200151#endif
152
Balbir Singh9a417852007-11-09 22:39:37 +0100153#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
Ankita Garg46ac22b2008-07-01 14:30:06 +0530154static inline void sched_info_reset_dequeued(struct task_struct *t)
155{
156 t->sched_info.last_queued = 0;
157}
158
Ingo Molnar425e0962007-07-09 18:51:58 +0200159/*
160 * Called when a process is dequeued from the active array and given
161 * the cpu. We should note that with the exception of interactive
162 * tasks, the expired queue will become the active queue after the active
163 * queue is empty, without explicitly dequeuing and requeuing tasks in the
164 * expired queue. (Interactive tasks may be requeued directly to the
165 * active queue, thus delaying tasks in the expired queue from running;
166 * see scheduler_tick()).
167 *
Ankita Garg46ac22b2008-07-01 14:30:06 +0530168 * Though we are interested in knowing how long it was from the *first* time a
169 * task was queued to the time that it finally hit a cpu, we call this routine
170 * from dequeue_task() to account for possible rq->clock skew across cpus. The
171 * delta taken on each cpu would annul the skew.
Ingo Molnar425e0962007-07-09 18:51:58 +0200172 */
173static inline void sched_info_dequeued(struct task_struct *t)
174{
Ankita Garg46ac22b2008-07-01 14:30:06 +0530175 unsigned long long now = task_rq(t)->clock, delta = 0;
176
177 if (unlikely(sched_info_on()))
178 if (t->sched_info.last_queued)
179 delta = now - t->sched_info.last_queued;
180 sched_info_reset_dequeued(t);
181 t->sched_info.run_delay += delta;
182
183 rq_sched_info_dequeued(task_rq(t), delta);
Ingo Molnar425e0962007-07-09 18:51:58 +0200184}
185
186/*
187 * Called when a task finally hits the cpu. We can now calculate how
188 * long it was waiting to run. We also note when it began so that we
189 * can keep stats on how long its timeslice is.
190 */
191static void sched_info_arrive(struct task_struct *t)
192{
Balbir Singh9a417852007-11-09 22:39:37 +0100193 unsigned long long now = task_rq(t)->clock, delta = 0;
Ingo Molnar425e0962007-07-09 18:51:58 +0200194
195 if (t->sched_info.last_queued)
196 delta = now - t->sched_info.last_queued;
Ankita Garg46ac22b2008-07-01 14:30:06 +0530197 sched_info_reset_dequeued(t);
Ingo Molnar425e0962007-07-09 18:51:58 +0200198 t->sched_info.run_delay += delta;
199 t->sched_info.last_arrival = now;
Ingo Molnar2d723762007-10-15 17:00:12 +0200200 t->sched_info.pcount++;
Ingo Molnar425e0962007-07-09 18:51:58 +0200201
202 rq_sched_info_arrive(task_rq(t), delta);
203}
204
205/*
206 * Called when a process is queued into either the active or expired
207 * array. The time is noted and later used to determine how long we
208 * had to wait for us to reach the cpu. Since the expired queue will
209 * become the active queue after active queue is empty, without dequeuing
210 * and requeuing any tasks, we are interested in queuing to either. It
211 * is unusual but not impossible for tasks to be dequeued and immediately
212 * requeued in the same or another array: this can happen in sched_yield(),
213 * set_user_nice(), and even load_balance() as it moves tasks from runqueue
214 * to runqueue.
215 *
216 * This function is only called from enqueue_task(), but also only updates
217 * the timestamp if it is already not set. It's assumed that
218 * sched_info_dequeued() will clear that stamp when appropriate.
219 */
220static inline void sched_info_queued(struct task_struct *t)
221{
222 if (unlikely(sched_info_on()))
223 if (!t->sched_info.last_queued)
Balbir Singh9a417852007-11-09 22:39:37 +0100224 t->sched_info.last_queued = task_rq(t)->clock;
Ingo Molnar425e0962007-07-09 18:51:58 +0200225}
226
227/*
228 * Called when a process ceases being the active-running process, either
229 * voluntarily or involuntarily. Now we can calculate how long we ran.
Bharath Ravid4abc232008-06-16 15:11:01 +0530230 * Also, if the process is still in the TASK_RUNNING state, call
231 * sched_info_queued() to mark that it has now again started waiting on
232 * the runqueue.
Ingo Molnar425e0962007-07-09 18:51:58 +0200233 */
234static inline void sched_info_depart(struct task_struct *t)
235{
Balbir Singh9a417852007-11-09 22:39:37 +0100236 unsigned long long delta = task_rq(t)->clock -
237 t->sched_info.last_arrival;
Ingo Molnar425e0962007-07-09 18:51:58 +0200238
Ingo Molnar425e0962007-07-09 18:51:58 +0200239 rq_sched_info_depart(task_rq(t), delta);
Bharath Ravid4abc232008-06-16 15:11:01 +0530240
241 if (t->state == TASK_RUNNING)
242 sched_info_queued(t);
Ingo Molnar425e0962007-07-09 18:51:58 +0200243}
244
245/*
246 * Called when tasks are switched involuntarily due, typically, to expiring
247 * their time slice. (This may also be called when switching to or from
248 * the idle task.) We are only called when prev != next.
249 */
250static inline void
251__sched_info_switch(struct task_struct *prev, struct task_struct *next)
252{
253 struct rq *rq = task_rq(prev);
254
255 /*
256 * prev now departs the cpu. It's not interesting to record
257 * stats about how efficient we were at scheduling the idle
258 * process, however.
259 */
260 if (prev != rq->idle)
261 sched_info_depart(prev);
262
263 if (next != rq->idle)
264 sched_info_arrive(next);
265}
266static inline void
267sched_info_switch(struct task_struct *prev, struct task_struct *next)
268{
269 if (unlikely(sched_info_on()))
270 __sched_info_switch(prev, next);
271}
272#else
Ankita Garg46ac22b2008-07-01 14:30:06 +0530273#define sched_info_queued(t) do { } while (0)
274#define sched_info_reset_dequeued(t) do { } while (0)
275#define sched_info_dequeued(t) do { } while (0)
276#define sched_info_switch(t, next) do { } while (0)
Balbir Singh9a417852007-11-09 22:39:37 +0100277#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
Ingo Molnar425e0962007-07-09 18:51:58 +0200278
Frank Mayharbb34d922008-09-12 09:54:39 -0700279/*
280 * The following are functions that support scheduler-internal time accounting.
281 * These functions are generally called at the timer tick. None of this depends
282 * on CONFIG_SCHEDSTATS.
283 */
284
Frank Mayharbb34d922008-09-12 09:54:39 -0700285/**
Frank Mayhar7086efe2008-09-12 09:54:39 -0700286 * account_group_user_time - Maintain utime for a thread group.
Frank Mayharbb34d922008-09-12 09:54:39 -0700287 *
Frank Mayhar7086efe2008-09-12 09:54:39 -0700288 * @tsk: Pointer to task structure.
289 * @cputime: Time value by which to increment the utime field of the
290 * thread_group_cputime structure.
Frank Mayharbb34d922008-09-12 09:54:39 -0700291 *
292 * If thread group time is being maintained, get the structure for the
293 * running CPU and update the utime field there.
294 */
Frank Mayhar7086efe2008-09-12 09:54:39 -0700295static inline void account_group_user_time(struct task_struct *tsk,
296 cputime_t cputime)
Frank Mayharbb34d922008-09-12 09:54:39 -0700297{
Oleg Nesterov48286d52010-06-11 01:09:52 +0200298 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
Frank Mayharbb34d922008-09-12 09:54:39 -0700299
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100300 if (!cputimer->running)
301 return;
302
303 spin_lock(&cputimer->lock);
304 cputimer->cputime.utime =
305 cputime_add(cputimer->cputime.utime, cputime);
306 spin_unlock(&cputimer->lock);
Frank Mayharbb34d922008-09-12 09:54:39 -0700307}
308
309/**
Frank Mayhar7086efe2008-09-12 09:54:39 -0700310 * account_group_system_time - Maintain stime for a thread group.
Frank Mayharbb34d922008-09-12 09:54:39 -0700311 *
Frank Mayhar7086efe2008-09-12 09:54:39 -0700312 * @tsk: Pointer to task structure.
313 * @cputime: Time value by which to increment the stime field of the
314 * thread_group_cputime structure.
Frank Mayharbb34d922008-09-12 09:54:39 -0700315 *
316 * If thread group time is being maintained, get the structure for the
317 * running CPU and update the stime field there.
318 */
Frank Mayhar7086efe2008-09-12 09:54:39 -0700319static inline void account_group_system_time(struct task_struct *tsk,
320 cputime_t cputime)
Frank Mayharbb34d922008-09-12 09:54:39 -0700321{
Oleg Nesterov48286d52010-06-11 01:09:52 +0200322 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
Frank Mayharbb34d922008-09-12 09:54:39 -0700323
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100324 if (!cputimer->running)
325 return;
326
327 spin_lock(&cputimer->lock);
328 cputimer->cputime.stime =
329 cputime_add(cputimer->cputime.stime, cputime);
330 spin_unlock(&cputimer->lock);
Frank Mayharbb34d922008-09-12 09:54:39 -0700331}
332
333/**
Frank Mayhar7086efe2008-09-12 09:54:39 -0700334 * account_group_exec_runtime - Maintain exec runtime for a thread group.
Frank Mayharbb34d922008-09-12 09:54:39 -0700335 *
Frank Mayhar7086efe2008-09-12 09:54:39 -0700336 * @tsk: Pointer to task structure.
Frank Mayharbb34d922008-09-12 09:54:39 -0700337 * @ns: Time value by which to increment the sum_exec_runtime field
Frank Mayhar7086efe2008-09-12 09:54:39 -0700338 * of the thread_group_cputime structure.
Frank Mayharbb34d922008-09-12 09:54:39 -0700339 *
340 * If thread group time is being maintained, get the structure for the
341 * running CPU and update the sum_exec_runtime field there.
342 */
Frank Mayhar7086efe2008-09-12 09:54:39 -0700343static inline void account_group_exec_runtime(struct task_struct *tsk,
344 unsigned long long ns)
Frank Mayharbb34d922008-09-12 09:54:39 -0700345{
Oleg Nesterov48286d52010-06-11 01:09:52 +0200346 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
Frank Mayharbb34d922008-09-12 09:54:39 -0700347
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100348 if (!cputimer->running)
349 return;
350
351 spin_lock(&cputimer->lock);
352 cputimer->cputime.sum_exec_runtime += ns;
353 spin_unlock(&cputimer->lock);
Frank Mayharbb34d922008-09-12 09:54:39 -0700354}