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-rw-r--r--kernel/posix-cpu-timers.c117
1 files changed, 112 insertions, 5 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index fa07da94d7be..2313a4cc14ea 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -230,6 +230,71 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
230 return 0; 230 return 0;
231} 231}
232 232
233void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
234{
235 struct sighand_struct *sighand;
236 struct signal_struct *sig;
237 struct task_struct *t;
238
239 *times = INIT_CPUTIME;
240
241 rcu_read_lock();
242 sighand = rcu_dereference(tsk->sighand);
243 if (!sighand)
244 goto out;
245
246 sig = tsk->signal;
247
248 t = tsk;
249 do {
250 times->utime = cputime_add(times->utime, t->utime);
251 times->stime = cputime_add(times->stime, t->stime);
252 times->sum_exec_runtime += t->se.sum_exec_runtime;
253
254 t = next_thread(t);
255 } while (t != tsk);
256
257 times->utime = cputime_add(times->utime, sig->utime);
258 times->stime = cputime_add(times->stime, sig->stime);
259 times->sum_exec_runtime += sig->sum_sched_runtime;
260out:
261 rcu_read_unlock();
262}
263
264static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
265{
266 if (cputime_gt(b->utime, a->utime))
267 a->utime = b->utime;
268
269 if (cputime_gt(b->stime, a->stime))
270 a->stime = b->stime;
271
272 if (b->sum_exec_runtime > a->sum_exec_runtime)
273 a->sum_exec_runtime = b->sum_exec_runtime;
274}
275
276void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
277{
278 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
279 struct task_cputime sum;
280 unsigned long flags;
281
282 spin_lock_irqsave(&cputimer->lock, flags);
283 if (!cputimer->running) {
284 cputimer->running = 1;
285 /*
286 * The POSIX timer interface allows for absolute time expiry
287 * values through the TIMER_ABSTIME flag, therefore we have
288 * to synchronize the timer to the clock every time we start
289 * it.
290 */
291 thread_group_cputime(tsk, &sum);
292 update_gt_cputime(&cputimer->cputime, &sum);
293 }
294 *times = cputimer->cputime;
295 spin_unlock_irqrestore(&cputimer->lock, flags);
296}
297
233/* 298/*
234 * Sample a process (thread group) clock for the given group_leader task. 299 * Sample a process (thread group) clock for the given group_leader task.
235 * Must be called with tasklist_lock held for reading. 300 * Must be called with tasklist_lock held for reading.
@@ -457,7 +522,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk)
457{ 522{
458 struct task_cputime cputime; 523 struct task_cputime cputime;
459 524
460 thread_group_cputime(tsk, &cputime); 525 thread_group_cputimer(tsk, &cputime);
461 cleanup_timers(tsk->signal->cpu_timers, 526 cleanup_timers(tsk->signal->cpu_timers,
462 cputime.utime, cputime.stime, cputime.sum_exec_runtime); 527 cputime.utime, cputime.stime, cputime.sum_exec_runtime);
463} 528}
@@ -964,6 +1029,19 @@ static void check_thread_timers(struct task_struct *tsk,
964 } 1029 }
965} 1030}
966 1031
1032static void stop_process_timers(struct task_struct *tsk)
1033{
1034 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
1035 unsigned long flags;
1036
1037 if (!cputimer->running)
1038 return;
1039
1040 spin_lock_irqsave(&cputimer->lock, flags);
1041 cputimer->running = 0;
1042 spin_unlock_irqrestore(&cputimer->lock, flags);
1043}
1044
967/* 1045/*
968 * Check for any per-thread CPU timers that have fired and move them 1046 * Check for any per-thread CPU timers that have fired and move them
969 * off the tsk->*_timers list onto the firing list. Per-thread timers 1047 * off the tsk->*_timers list onto the firing list. Per-thread timers
@@ -987,13 +1065,15 @@ static void check_process_timers(struct task_struct *tsk,
987 sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY && 1065 sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
988 list_empty(&timers[CPUCLOCK_VIRT]) && 1066 list_empty(&timers[CPUCLOCK_VIRT]) &&
989 cputime_eq(sig->it_virt_expires, cputime_zero) && 1067 cputime_eq(sig->it_virt_expires, cputime_zero) &&
990 list_empty(&timers[CPUCLOCK_SCHED])) 1068 list_empty(&timers[CPUCLOCK_SCHED])) {
1069 stop_process_timers(tsk);
991 return; 1070 return;
1071 }
992 1072
993 /* 1073 /*
994 * Collect the current process totals. 1074 * Collect the current process totals.
995 */ 1075 */
996 thread_group_cputime(tsk, &cputime); 1076 thread_group_cputimer(tsk, &cputime);
997 utime = cputime.utime; 1077 utime = cputime.utime;
998 ptime = cputime_add(utime, cputime.stime); 1078 ptime = cputime_add(utime, cputime.stime);
999 sum_sched_runtime = cputime.sum_exec_runtime; 1079 sum_sched_runtime = cputime.sum_exec_runtime;
@@ -1259,7 +1339,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
1259 if (!task_cputime_zero(&sig->cputime_expires)) { 1339 if (!task_cputime_zero(&sig->cputime_expires)) {
1260 struct task_cputime group_sample; 1340 struct task_cputime group_sample;
1261 1341
1262 thread_group_cputime(tsk, &group_sample); 1342 thread_group_cputimer(tsk, &group_sample);
1263 if (task_cputime_expired(&group_sample, &sig->cputime_expires)) 1343 if (task_cputime_expired(&group_sample, &sig->cputime_expires))
1264 return 1; 1344 return 1;
1265 } 1345 }
@@ -1329,6 +1409,33 @@ void run_posix_cpu_timers(struct task_struct *tsk)
1329} 1409}
1330 1410
1331/* 1411/*
1412 * Sample a process (thread group) timer for the given group_leader task.
1413 * Must be called with tasklist_lock held for reading.
1414 */
1415static int cpu_timer_sample_group(const clockid_t which_clock,
1416 struct task_struct *p,
1417 union cpu_time_count *cpu)
1418{
1419 struct task_cputime cputime;
1420
1421 thread_group_cputimer(p, &cputime);
1422 switch (CPUCLOCK_WHICH(which_clock)) {
1423 default:
1424 return -EINVAL;
1425 case CPUCLOCK_PROF:
1426 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
1427 break;
1428 case CPUCLOCK_VIRT:
1429 cpu->cpu = cputime.utime;
1430 break;
1431 case CPUCLOCK_SCHED:
1432 cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
1433 break;
1434 }
1435 return 0;
1436}
1437
1438/*
1332 * Set one of the process-wide special case CPU timers. 1439 * Set one of the process-wide special case CPU timers.
1333 * The tsk->sighand->siglock must be held by the caller. 1440 * The tsk->sighand->siglock must be held by the caller.
1334 * The *newval argument is relative and we update it to be absolute, *oldval 1441 * The *newval argument is relative and we update it to be absolute, *oldval
@@ -1341,7 +1448,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
1341 struct list_head *head; 1448 struct list_head *head;
1342 1449
1343 BUG_ON(clock_idx == CPUCLOCK_SCHED); 1450 BUG_ON(clock_idx == CPUCLOCK_SCHED);
1344 cpu_clock_sample_group(clock_idx, tsk, &now); 1451 cpu_timer_sample_group(clock_idx, tsk, &now);
1345 1452
1346 if (oldval) { 1453 if (oldval) {
1347 if (!cputime_eq(*oldval, cputime_zero)) { 1454 if (!cputime_eq(*oldval, cputime_zero)) {