Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux...
[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,
46                                           sched_domain_span(sd));
47                         seq_printf(seq, "domain%d %s", dcount++, mask_str);
48                         for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
49                                         itype++) {
50                                 seq_printf(seq, " %u %u %u %u %u %u %u %u",
51                                     sd->lb_count[itype],
52                                     sd->lb_balanced[itype],
53                                     sd->lb_failed[itype],
54                                     sd->lb_imbalance[itype],
55                                     sd->lb_gained[itype],
56                                     sd->lb_hot_gained[itype],
57                                     sd->lb_nobusyq[itype],
58                                     sd->lb_nobusyg[itype]);
59                         }
60                         seq_printf(seq,
61                                    " %u %u %u %u %u %u %u %u %u %u %u %u\n",
62                             sd->alb_count, sd->alb_failed, sd->alb_pushed,
63                             sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
64                             sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
65                             sd->ttwu_wake_remote, sd->ttwu_move_affine,
66                             sd->ttwu_move_balance);
67                 }
68                 preempt_enable();
69 #endif
70         }
71         kfree(mask_str);
72         return 0;
73 }
74
75 static int schedstat_open(struct inode *inode, struct file *file)
76 {
77         unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
78         char *buf = kmalloc(size, GFP_KERNEL);
79         struct seq_file *m;
80         int res;
81
82         if (!buf)
83                 return -ENOMEM;
84         res = single_open(file, show_schedstat, NULL);
85         if (!res) {
86                 m = file->private_data;
87                 m->buf = buf;
88                 m->size = size;
89         } else
90                 kfree(buf);
91         return res;
92 }
93
94 static const struct file_operations proc_schedstat_operations = {
95         .open    = schedstat_open,
96         .read    = seq_read,
97         .llseek  = seq_lseek,
98         .release = single_release,
99 };
100
101 static int __init proc_schedstat_init(void)
102 {
103         proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
104         return 0;
105 }
106 module_init(proc_schedstat_init);
107
108 /*
109  * Expects runqueue lock to be held for atomicity of update
110  */
111 static inline void
112 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
113 {
114         if (rq) {
115                 rq->rq_sched_info.run_delay += delta;
116                 rq->rq_sched_info.pcount++;
117         }
118 }
119
120 /*
121  * Expects runqueue lock to be held for atomicity of update
122  */
123 static inline void
124 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
125 {
126         if (rq)
127                 rq->rq_cpu_time += delta;
128 }
129
130 static inline void
131 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
132 {
133         if (rq)
134                 rq->rq_sched_info.run_delay += delta;
135 }
136 # define schedstat_inc(rq, field)       do { (rq)->field++; } while (0)
137 # define schedstat_add(rq, field, amt)  do { (rq)->field += (amt); } while (0)
138 # define schedstat_set(var, val)        do { var = (val); } while (0)
139 #else /* !CONFIG_SCHEDSTATS */
140 static inline void
141 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
142 {}
143 static inline void
144 rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
145 {}
146 static inline void
147 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
148 {}
149 # define schedstat_inc(rq, field)       do { } while (0)
150 # define schedstat_add(rq, field, amt)  do { } while (0)
151 # define schedstat_set(var, val)        do { } while (0)
152 #endif
153
154 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
155 static inline void sched_info_reset_dequeued(struct task_struct *t)
156 {
157         t->sched_info.last_queued = 0;
158 }
159
160 /*
161  * Called when a process is dequeued from the active array and given
162  * the cpu.  We should note that with the exception of interactive
163  * tasks, the expired queue will become the active queue after the active
164  * queue is empty, without explicitly dequeuing and requeuing tasks in the
165  * expired queue.  (Interactive tasks may be requeued directly to the
166  * active queue, thus delaying tasks in the expired queue from running;
167  * see scheduler_tick()).
168  *
169  * Though we are interested in knowing how long it was from the *first* time a
170  * task was queued to the time that it finally hit a cpu, we call this routine
171  * from dequeue_task() to account for possible rq->clock skew across cpus. The
172  * delta taken on each cpu would annul the skew.
173  */
174 static inline void sched_info_dequeued(struct task_struct *t)
175 {
176         unsigned long long now = task_rq(t)->clock, delta = 0;
177
178         if (unlikely(sched_info_on()))
179                 if (t->sched_info.last_queued)
180                         delta = now - t->sched_info.last_queued;
181         sched_info_reset_dequeued(t);
182         t->sched_info.run_delay += delta;
183
184         rq_sched_info_dequeued(task_rq(t), delta);
185 }
186
187 /*
188  * Called when a task finally hits the cpu.  We can now calculate how
189  * long it was waiting to run.  We also note when it began so that we
190  * can keep stats on how long its timeslice is.
191  */
192 static void sched_info_arrive(struct task_struct *t)
193 {
194         unsigned long long now = task_rq(t)->clock, delta = 0;
195
196         if (t->sched_info.last_queued)
197                 delta = now - t->sched_info.last_queued;
198         sched_info_reset_dequeued(t);
199         t->sched_info.run_delay += delta;
200         t->sched_info.last_arrival = now;
201         t->sched_info.pcount++;
202
203         rq_sched_info_arrive(task_rq(t), delta);
204 }
205
206 /*
207  * Called when a process is queued into either the active or expired
208  * array.  The time is noted and later used to determine how long we
209  * had to wait for us to reach the cpu.  Since the expired queue will
210  * become the active queue after active queue is empty, without dequeuing
211  * and requeuing any tasks, we are interested in queuing to either. It
212  * is unusual but not impossible for tasks to be dequeued and immediately
213  * requeued in the same or another array: this can happen in sched_yield(),
214  * set_user_nice(), and even load_balance() as it moves tasks from runqueue
215  * to runqueue.
216  *
217  * This function is only called from enqueue_task(), but also only updates
218  * the timestamp if it is already not set.  It's assumed that
219  * sched_info_dequeued() will clear that stamp when appropriate.
220  */
221 static inline void sched_info_queued(struct task_struct *t)
222 {
223         if (unlikely(sched_info_on()))
224                 if (!t->sched_info.last_queued)
225                         t->sched_info.last_queued = task_rq(t)->clock;
226 }
227
228 /*
229  * Called when a process ceases being the active-running process, either
230  * voluntarily or involuntarily.  Now we can calculate how long we ran.
231  * Also, if the process is still in the TASK_RUNNING state, call
232  * sched_info_queued() to mark that it has now again started waiting on
233  * the runqueue.
234  */
235 static inline void sched_info_depart(struct task_struct *t)
236 {
237         unsigned long long delta = task_rq(t)->clock -
238                                         t->sched_info.last_arrival;
239
240         rq_sched_info_depart(task_rq(t), delta);
241
242         if (t->state == TASK_RUNNING)
243                 sched_info_queued(t);
244 }
245
246 /*
247  * Called when tasks are switched involuntarily due, typically, to expiring
248  * their time slice.  (This may also be called when switching to or from
249  * the idle task.)  We are only called when prev != next.
250  */
251 static inline void
252 __sched_info_switch(struct task_struct *prev, struct task_struct *next)
253 {
254         struct rq *rq = task_rq(prev);
255
256         /*
257          * prev now departs the cpu.  It's not interesting to record
258          * stats about how efficient we were at scheduling the idle
259          * process, however.
260          */
261         if (prev != rq->idle)
262                 sched_info_depart(prev);
263
264         if (next != rq->idle)
265                 sched_info_arrive(next);
266 }
267 static inline void
268 sched_info_switch(struct task_struct *prev, struct task_struct *next)
269 {
270         if (unlikely(sched_info_on()))
271                 __sched_info_switch(prev, next);
272 }
273 #else
274 #define sched_info_queued(t)                    do { } while (0)
275 #define sched_info_reset_dequeued(t)    do { } while (0)
276 #define sched_info_dequeued(t)                  do { } while (0)
277 #define sched_info_switch(t, next)              do { } while (0)
278 #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
279
280 /*
281  * The following are functions that support scheduler-internal time accounting.
282  * These functions are generally called at the timer tick.  None of this depends
283  * on CONFIG_SCHEDSTATS.
284  */
285
286 /**
287  * account_group_user_time - Maintain utime for a thread group.
288  *
289  * @tsk:        Pointer to task structure.
290  * @cputime:    Time value by which to increment the utime field of the
291  *              thread_group_cputime structure.
292  *
293  * If thread group time is being maintained, get the structure for the
294  * running CPU and update the utime field there.
295  */
296 static inline void account_group_user_time(struct task_struct *tsk,
297                                            cputime_t cputime)
298 {
299         struct signal_struct *sig;
300
301         /* tsk == current, ensure it is safe to use ->signal */
302         if (unlikely(tsk->exit_state))
303                 return;
304
305         sig = tsk->signal;
306         if (sig->cputime.totals) {
307                 struct task_cputime *times;
308
309                 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
310                 times->utime = cputime_add(times->utime, cputime);
311                 put_cpu_no_resched();
312         }
313 }
314
315 /**
316  * account_group_system_time - Maintain stime for a thread group.
317  *
318  * @tsk:        Pointer to task structure.
319  * @cputime:    Time value by which to increment the stime field of the
320  *              thread_group_cputime structure.
321  *
322  * If thread group time is being maintained, get the structure for the
323  * running CPU and update the stime field there.
324  */
325 static inline void account_group_system_time(struct task_struct *tsk,
326                                              cputime_t cputime)
327 {
328         struct signal_struct *sig;
329
330         /* tsk == current, ensure it is safe to use ->signal */
331         if (unlikely(tsk->exit_state))
332                 return;
333
334         sig = tsk->signal;
335         if (sig->cputime.totals) {
336                 struct task_cputime *times;
337
338                 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
339                 times->stime = cputime_add(times->stime, cputime);
340                 put_cpu_no_resched();
341         }
342 }
343
344 /**
345  * account_group_exec_runtime - Maintain exec runtime for a thread group.
346  *
347  * @tsk:        Pointer to task structure.
348  * @ns:         Time value by which to increment the sum_exec_runtime field
349  *              of the thread_group_cputime structure.
350  *
351  * If thread group time is being maintained, get the structure for the
352  * running CPU and update the sum_exec_runtime field there.
353  */
354 static inline void account_group_exec_runtime(struct task_struct *tsk,
355                                               unsigned long long ns)
356 {
357         struct signal_struct *sig;
358
359         sig = tsk->signal;
360         /* see __exit_signal()->task_rq_unlock_wait() */
361         barrier();
362         if (unlikely(!sig))
363                 return;
364
365         if (sig->cputime.totals) {
366                 struct task_cputime *times;
367
368                 times = per_cpu_ptr(sig->cputime.totals, get_cpu());
369                 times->sum_exec_runtime += ns;
370                 put_cpu_no_resched();
371         }
372 }