Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6.git] / kernel / sched_stats.h
1
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  */
7 #define SCHEDSTAT_VERSION 14
8
9 static int show_schedstat(struct seq_file *seq, void *v)
10 {
11         int cpu;
12         int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
13         char *mask_str = kmalloc(mask_len, GFP_KERNEL);
14
15         if (mask_str == NULL)
16                 return -ENOMEM;
17
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;
24                 int dcount = 0;
25 #endif
26
27                 /* runqueue-specific stats */
28                 seq_printf(seq,
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_cpu_time,
35                     rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
36
37                 seq_printf(seq, "\n");
38
39 #ifdef CONFIG_SMP
40                 /* domain-specific stats */
41                 preempt_disable();
42                 for_each_domain(cpu, sd) {
43                         enum cpu_idle_type itype;
44
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;
48                                         itype++) {
49                                 seq_printf(seq, " %u %u %u %u %u %u %u %u",
50                                     sd->lb_count[itype],
51                                     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                         }
59                         seq_printf(seq,
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);
66                 }
67                 preempt_enable();
68 #endif
69         }
70         kfree(mask_str);
71         return 0;
72 }
73
74 static 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
93 static const struct file_operations proc_schedstat_operations = {
94         .open    = schedstat_open,
95         .read    = seq_read,
96         .llseek  = seq_lseek,
97         .release = single_release,
98 };
99
100 static int __init proc_schedstat_init(void)
101 {
102         proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
103         return 0;
104 }
105 module_init(proc_schedstat_init);
106
107 /*
108  * Expects runqueue lock to be held for atomicity of update
109  */
110 static inline void
111 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
112 {
113         if (rq) {
114                 rq->rq_sched_info.run_delay += delta;
115                 rq->rq_sched_info.pcount++;
116         }
117 }
118
119 /*
120  * Expects runqueue lock to be held for atomicity of update
121  */
122 static inline void
123 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
124 {
125         if (rq)
126                 rq->rq_cpu_time += delta;
127 }
128
129 static inline void
130 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
131 {
132         if (rq)
133                 rq->rq_sched_info.run_delay += delta;
134 }
135 # define schedstat_inc(rq, field)       do { (rq)->field++; } while (0)
136 # define schedstat_add(rq, field, amt)  do { (rq)->field += (amt); } while (0)
137 # define schedstat_set(var, val)        do { var = (val); } while (0)
138 #else /* !CONFIG_SCHEDSTATS */
139 static inline void
140 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
141 {}
142 static inline void
143 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
144 {}
145 static inline void
146 rq_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)
150 # define schedstat_set(var, val)        do { } while (0)
151 #endif
152
153 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
154 static inline void sched_info_reset_dequeued(struct task_struct *t)
155 {
156         t->sched_info.last_queued = 0;
157 }
158
159 /*
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  *
168  * 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.
172  */
173 static inline void sched_info_dequeued(struct task_struct *t)
174 {
175         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);
184 }
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  */
191 static void sched_info_arrive(struct task_struct *t)
192 {
193         unsigned long long now = task_rq(t)->clock, delta = 0;
194
195         if (t->sched_info.last_queued)
196                 delta = now - t->sched_info.last_queued;
197         sched_info_reset_dequeued(t);
198         t->sched_info.run_delay += delta;
199         t->sched_info.last_arrival = now;
200         t->sched_info.pcount++;
201
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  */
220 static inline void sched_info_queued(struct task_struct *t)
221 {
222         if (unlikely(sched_info_on()))
223                 if (!t->sched_info.last_queued)
224                         t->sched_info.last_queued = task_rq(t)->clock;
225 }
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.
230  * 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.
233  */
234 static inline void sched_info_depart(struct task_struct *t)
235 {
236         unsigned long long delta = task_rq(t)->clock -
237                                         t->sched_info.last_arrival;
238
239         rq_sched_info_depart(task_rq(t), delta);
240
241         if (t->state == TASK_RUNNING)
242                 sched_info_queued(t);
243 }
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  */
250 static 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 }
266 static inline void
267 sched_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
273 #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)
277 #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
278
279 /*
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
285 /**
286  * account_group_user_time - Maintain utime for a thread group.
287  *
288  * @tsk:        Pointer to task structure.
289  * @cputime:    Time value by which to increment the utime field of the
290  *              thread_group_cputime structure.
291  *
292  * If thread group time is being maintained, get the structure for the
293  * running CPU and update the utime field there.
294  */
295 static inline void account_group_user_time(struct task_struct *tsk,
296                                            cputime_t cputime)
297 {
298         struct signal_struct *sig;
299
300         /* tsk == current, ensure it is safe to use ->signal */
301         if (unlikely(tsk->exit_state))
302                 return;
303
304         sig = tsk->signal;
305         if (sig->cputime.totals) {
306                 struct task_cputime *times;
307
308                 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
309                 times->utime = cputime_add(times->utime, cputime);
310                 put_cpu_no_resched();
311         }
312 }
313
314 /**
315  * account_group_system_time - Maintain stime for a thread group.
316  *
317  * @tsk:        Pointer to task structure.
318  * @cputime:    Time value by which to increment the stime field of the
319  *              thread_group_cputime structure.
320  *
321  * If thread group time is being maintained, get the structure for the
322  * running CPU and update the stime field there.
323  */
324 static inline void account_group_system_time(struct task_struct *tsk,
325                                              cputime_t cputime)
326 {
327         struct signal_struct *sig;
328
329         /* tsk == current, ensure it is safe to use ->signal */
330         if (unlikely(tsk->exit_state))
331                 return;
332
333         sig = tsk->signal;
334         if (sig->cputime.totals) {
335                 struct task_cputime *times;
336
337                 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
338                 times->stime = cputime_add(times->stime, cputime);
339                 put_cpu_no_resched();
340         }
341 }
342
343 /**
344  * account_group_exec_runtime - Maintain exec runtime for a thread group.
345  *
346  * @tsk:        Pointer to task structure.
347  * @ns:         Time value by which to increment the sum_exec_runtime field
348  *              of the thread_group_cputime structure.
349  *
350  * If thread group time is being maintained, get the structure for the
351  * running CPU and update the sum_exec_runtime field there.
352  */
353 static inline void account_group_exec_runtime(struct task_struct *tsk,
354                                               unsigned long long ns)
355 {
356         struct signal_struct *sig;
357
358         sig = tsk->signal;
359         /* see __exit_signal()->task_rq_unlock_wait() */
360         barrier();
361         if (unlikely(!sig))
362                 return;
363
364         if (sig->cputime.totals) {
365                 struct task_cputime *times;
366
367                 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
368                 times->sum_exec_runtime += ns;
369                 put_cpu_no_resched();
370         }
371 }