2 #ifdef CONFIG_SCHEDSTATS
4 * bump this up when changing the output format or the meaning of an existing
5 * format, so that tools can adapt (or abort)
7 #define SCHEDSTAT_VERSION 14
9 static int show_schedstat(struct seq_file *seq, void *v)
12 int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
13 char *mask_str = kmalloc(mask_len, GFP_KERNEL);
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);
23 struct sched_domain *sd;
27 /* runqueue-specific stats */
29 "cpu%d %u %u %u %u %u %u %u %u %u %llu %llu %lu",
30 cpu, rq->yld_both_empty,
31 rq->yld_act_empty, rq->yld_exp_empty, rq->yld_count,
32 rq->sched_switch, rq->sched_count, rq->sched_goidle,
33 rq->ttwu_count, rq->ttwu_local,
34 rq->rq_sched_info.cpu_time,
35 rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
37 seq_printf(seq, "\n");
40 /* domain-specific stats */
42 for_each_domain(cpu, sd) {
43 enum cpu_idle_type itype;
45 cpumask_scnprintf(mask_str, mask_len, sd->span);
46 seq_printf(seq, "domain%d %s", dcount++, mask_str);
47 for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
49 seq_printf(seq, " %u %u %u %u %u %u %u %u",
51 sd->lb_balanced[itype],
53 sd->lb_imbalance[itype],
55 sd->lb_hot_gained[itype],
56 sd->lb_nobusyq[itype],
57 sd->lb_nobusyg[itype]);
60 " %u %u %u %u %u %u %u %u %u %u %u %u\n",
61 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,
64 sd->ttwu_wake_remote, sd->ttwu_move_affine,
65 sd->ttwu_move_balance);
74 static int schedstat_open(struct inode *inode, struct file *file)
76 unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
77 char *buf = kmalloc(size, GFP_KERNEL);
83 res = single_open(file, show_schedstat, NULL);
85 m = file->private_data;
93 const struct file_operations proc_schedstat_operations = {
94 .open = schedstat_open,
97 .release = single_release,
101 * Expects runqueue lock to be held for atomicity of update
104 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
107 rq->rq_sched_info.run_delay += delta;
108 rq->rq_sched_info.pcount++;
113 * Expects runqueue lock to be held for atomicity of update
116 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
119 rq->rq_sched_info.cpu_time += delta;
123 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
126 rq->rq_sched_info.run_delay += delta;
128 # define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
129 # define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
130 # define schedstat_set(var, val) do { var = (val); } while (0)
131 #else /* !CONFIG_SCHEDSTATS */
133 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
136 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
139 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
141 # define schedstat_inc(rq, field) do { } while (0)
142 # define schedstat_add(rq, field, amt) do { } while (0)
143 # define schedstat_set(var, val) do { } while (0)
146 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
147 static inline void sched_info_reset_dequeued(struct task_struct *t)
149 t->sched_info.last_queued = 0;
153 * Called when a process is dequeued from the active array and given
154 * the cpu. We should note that with the exception of interactive
155 * tasks, the expired queue will become the active queue after the active
156 * queue is empty, without explicitly dequeuing and requeuing tasks in the
157 * expired queue. (Interactive tasks may be requeued directly to the
158 * active queue, thus delaying tasks in the expired queue from running;
159 * see scheduler_tick()).
161 * Though we are interested in knowing how long it was from the *first* time a
162 * task was queued to the time that it finally hit a cpu, we call this routine
163 * from dequeue_task() to account for possible rq->clock skew across cpus. The
164 * delta taken on each cpu would annul the skew.
166 static inline void sched_info_dequeued(struct task_struct *t)
168 unsigned long long now = task_rq(t)->clock, delta = 0;
170 if (unlikely(sched_info_on()))
171 if (t->sched_info.last_queued)
172 delta = now - t->sched_info.last_queued;
173 sched_info_reset_dequeued(t);
174 t->sched_info.run_delay += delta;
176 rq_sched_info_dequeued(task_rq(t), delta);
180 * Called when a task finally hits the cpu. We can now calculate how
181 * long it was waiting to run. We also note when it began so that we
182 * can keep stats on how long its timeslice is.
184 static void sched_info_arrive(struct task_struct *t)
186 unsigned long long now = task_rq(t)->clock, delta = 0;
188 if (t->sched_info.last_queued)
189 delta = now - t->sched_info.last_queued;
190 sched_info_reset_dequeued(t);
191 t->sched_info.run_delay += delta;
192 t->sched_info.last_arrival = now;
193 t->sched_info.pcount++;
195 rq_sched_info_arrive(task_rq(t), delta);
199 * Called when a process is queued into either the active or expired
200 * array. The time is noted and later used to determine how long we
201 * had to wait for us to reach the cpu. Since the expired queue will
202 * become the active queue after active queue is empty, without dequeuing
203 * and requeuing any tasks, we are interested in queuing to either. It
204 * is unusual but not impossible for tasks to be dequeued and immediately
205 * requeued in the same or another array: this can happen in sched_yield(),
206 * set_user_nice(), and even load_balance() as it moves tasks from runqueue
209 * This function is only called from enqueue_task(), but also only updates
210 * the timestamp if it is already not set. It's assumed that
211 * sched_info_dequeued() will clear that stamp when appropriate.
213 static inline void sched_info_queued(struct task_struct *t)
215 if (unlikely(sched_info_on()))
216 if (!t->sched_info.last_queued)
217 t->sched_info.last_queued = task_rq(t)->clock;
221 * Called when a process ceases being the active-running process, either
222 * voluntarily or involuntarily. Now we can calculate how long we ran.
223 * Also, if the process is still in the TASK_RUNNING state, call
224 * sched_info_queued() to mark that it has now again started waiting on
227 static inline void sched_info_depart(struct task_struct *t)
229 unsigned long long delta = task_rq(t)->clock -
230 t->sched_info.last_arrival;
232 t->sched_info.cpu_time += delta;
233 rq_sched_info_depart(task_rq(t), delta);
235 if (t->state == TASK_RUNNING)
236 sched_info_queued(t);
240 * Called when tasks are switched involuntarily due, typically, to expiring
241 * their time slice. (This may also be called when switching to or from
242 * the idle task.) We are only called when prev != next.
245 __sched_info_switch(struct task_struct *prev, struct task_struct *next)
247 struct rq *rq = task_rq(prev);
250 * prev now departs the cpu. It's not interesting to record
251 * stats about how efficient we were at scheduling the idle
254 if (prev != rq->idle)
255 sched_info_depart(prev);
257 if (next != rq->idle)
258 sched_info_arrive(next);
261 sched_info_switch(struct task_struct *prev, struct task_struct *next)
263 if (unlikely(sched_info_on()))
264 __sched_info_switch(prev, next);
267 #define sched_info_queued(t) do { } while (0)
268 #define sched_info_reset_dequeued(t) do { } while (0)
269 #define sched_info_dequeued(t) do { } while (0)
270 #define sched_info_switch(t, next) do { } while (0)
271 #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
274 * The following are functions that support scheduler-internal time accounting.
275 * These functions are generally called at the timer tick. None of this depends
276 * on CONFIG_SCHEDSTATS.
280 * account_group_user_time - Maintain utime for a thread group.
282 * @tsk: Pointer to task structure.
283 * @cputime: Time value by which to increment the utime field of the
284 * thread_group_cputime structure.
286 * If thread group time is being maintained, get the structure for the
287 * running CPU and update the utime field there.
289 static inline void account_group_user_time(struct task_struct *tsk,
292 struct signal_struct *sig;
297 if (sig->cputime.totals) {
298 struct task_cputime *times;
300 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
301 times->utime = cputime_add(times->utime, cputime);
302 put_cpu_no_resched();
307 * account_group_system_time - Maintain stime for a thread group.
309 * @tsk: Pointer to task structure.
310 * @cputime: Time value by which to increment the stime field of the
311 * thread_group_cputime structure.
313 * If thread group time is being maintained, get the structure for the
314 * running CPU and update the stime field there.
316 static inline void account_group_system_time(struct task_struct *tsk,
319 struct signal_struct *sig;
324 if (sig->cputime.totals) {
325 struct task_cputime *times;
327 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
328 times->stime = cputime_add(times->stime, cputime);
329 put_cpu_no_resched();
334 * account_group_exec_runtime - Maintain exec runtime for a thread group.
336 * @tsk: Pointer to task structure.
337 * @ns: Time value by which to increment the sum_exec_runtime field
338 * of the thread_group_cputime structure.
340 * If thread group time is being maintained, get the structure for the
341 * running CPU and update the sum_exec_runtime field there.
343 static inline void account_group_exec_runtime(struct task_struct *tsk,
344 unsigned long long ns)
346 struct signal_struct *sig;
351 if (sig->cputime.totals) {
352 struct task_cputime *times;
354 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
355 times->sum_exec_runtime += ns;
356 put_cpu_no_resched();