blob: 438ff4523513b945962e50a98eb8d4e2fbb28f5d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Implement CPU time clocks for the POSIX clock interface.
3 */
4
5#include <linux/sched.h>
6#include <linux/posix-timers.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/errno.h>
Roman Zippelf8bd2252008-05-01 04:34:31 -07008#include <linux/math64.h>
9#include <asm/uaccess.h>
Frank Mayharbb34d922008-09-12 09:54:39 -070010#include <linux/kernel_stat.h>
Xiao Guangrong3f0a5252009-08-10 10:52:30 +080011#include <trace/events/timer.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012
Frank Mayharf06febc2008-09-12 09:54:39 -070013/*
Frank Mayharf06febc2008-09-12 09:54:39 -070014 * Called after updating RLIMIT_CPU to set timer expiration if necessary.
15 */
16void update_rlimit_cpu(unsigned long rlim_new)
17{
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +020018 cputime_t cputime = secs_to_cputime(rlim_new);
19 struct signal_struct *const sig = current->signal;
Frank Mayharf06febc2008-09-12 09:54:39 -070020
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +020021 if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
22 cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
Frank Mayharf06febc2008-09-12 09:54:39 -070023 spin_lock_irq(&current->sighand->siglock);
24 set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
25 spin_unlock_irq(&current->sighand->siglock);
26 }
27}
28
Thomas Gleixnera924b042006-01-09 20:52:27 -080029static int check_clock(const clockid_t which_clock)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030{
31 int error = 0;
32 struct task_struct *p;
33 const pid_t pid = CPUCLOCK_PID(which_clock);
34
35 if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
36 return -EINVAL;
37
38 if (pid == 0)
39 return 0;
40
41 read_lock(&tasklist_lock);
Pavel Emelyanov8dc86af2008-02-08 04:21:52 -080042 p = find_task_by_vpid(pid);
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -070043 if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
44 same_thread_group(p, current) : thread_group_leader(p))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 error = -EINVAL;
46 }
47 read_unlock(&tasklist_lock);
48
49 return error;
50}
51
52static inline union cpu_time_count
Thomas Gleixnera924b042006-01-09 20:52:27 -080053timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054{
55 union cpu_time_count ret;
56 ret.sched = 0; /* high half always zero when .cpu used */
57 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
Oleg Nesterovee500f22005-11-28 13:43:55 -080058 ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 } else {
60 ret.cpu = timespec_to_cputime(tp);
61 }
62 return ret;
63}
64
Thomas Gleixnera924b042006-01-09 20:52:27 -080065static void sample_to_timespec(const clockid_t which_clock,
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 union cpu_time_count cpu,
67 struct timespec *tp)
68{
Roman Zippelf8bd2252008-05-01 04:34:31 -070069 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
70 *tp = ns_to_timespec(cpu.sched);
71 else
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 cputime_to_timespec(cpu.cpu, tp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073}
74
Thomas Gleixnera924b042006-01-09 20:52:27 -080075static inline int cpu_time_before(const clockid_t which_clock,
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 union cpu_time_count now,
77 union cpu_time_count then)
78{
79 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
80 return now.sched < then.sched;
81 } else {
82 return cputime_lt(now.cpu, then.cpu);
83 }
84}
Thomas Gleixnera924b042006-01-09 20:52:27 -080085static inline void cpu_time_add(const clockid_t which_clock,
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 union cpu_time_count *acc,
87 union cpu_time_count val)
88{
89 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
90 acc->sched += val.sched;
91 } else {
92 acc->cpu = cputime_add(acc->cpu, val.cpu);
93 }
94}
Thomas Gleixnera924b042006-01-09 20:52:27 -080095static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 union cpu_time_count a,
97 union cpu_time_count b)
98{
99 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
100 a.sched -= b.sched;
101 } else {
102 a.cpu = cputime_sub(a.cpu, b.cpu);
103 }
104 return a;
105}
106
107/*
Thomas Gleixnerac08c262006-10-17 00:09:39 -0700108 * Divide and limit the result to res >= 1
109 *
110 * This is necessary to prevent signal delivery starvation, when the result of
111 * the division would be rounded down to 0.
112 */
113static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div)
114{
115 cputime_t res = cputime_div(time, div);
116
117 return max_t(cputime_t, res, 1);
118}
119
120/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 * Update expiry time from increment, and increase overrun count,
122 * given the current clock sample.
123 */
Oleg Nesterov7a4ed932005-10-26 20:26:53 +0400124static void bump_cpu_timer(struct k_itimer *timer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 union cpu_time_count now)
126{
127 int i;
128
129 if (timer->it.cpu.incr.sched == 0)
130 return;
131
132 if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
133 unsigned long long delta, incr;
134
135 if (now.sched < timer->it.cpu.expires.sched)
136 return;
137 incr = timer->it.cpu.incr.sched;
138 delta = now.sched + incr - timer->it.cpu.expires.sched;
139 /* Don't use (incr*2 < delta), incr*2 might overflow. */
140 for (i = 0; incr < delta - incr; i++)
141 incr = incr << 1;
142 for (; i >= 0; incr >>= 1, i--) {
Oleg Nesterov7a4ed932005-10-26 20:26:53 +0400143 if (delta < incr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 continue;
145 timer->it.cpu.expires.sched += incr;
146 timer->it_overrun += 1 << i;
147 delta -= incr;
148 }
149 } else {
150 cputime_t delta, incr;
151
152 if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
153 return;
154 incr = timer->it.cpu.incr.cpu;
155 delta = cputime_sub(cputime_add(now.cpu, incr),
156 timer->it.cpu.expires.cpu);
157 /* Don't use (incr*2 < delta), incr*2 might overflow. */
158 for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
159 incr = cputime_add(incr, incr);
160 for (; i >= 0; incr = cputime_halve(incr), i--) {
Oleg Nesterov7a4ed932005-10-26 20:26:53 +0400161 if (cputime_lt(delta, incr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 continue;
163 timer->it.cpu.expires.cpu =
164 cputime_add(timer->it.cpu.expires.cpu, incr);
165 timer->it_overrun += 1 << i;
166 delta = cputime_sub(delta, incr);
167 }
168 }
169}
170
171static inline cputime_t prof_ticks(struct task_struct *p)
172{
173 return cputime_add(p->utime, p->stime);
174}
175static inline cputime_t virt_ticks(struct task_struct *p)
176{
177 return p->utime;
178}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
Thomas Gleixnera924b042006-01-09 20:52:27 -0800180int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181{
182 int error = check_clock(which_clock);
183 if (!error) {
184 tp->tv_sec = 0;
185 tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
186 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
187 /*
188 * If sched_clock is using a cycle counter, we
189 * don't have any idea of its true resolution
190 * exported, but it is much more than 1s/HZ.
191 */
192 tp->tv_nsec = 1;
193 }
194 }
195 return error;
196}
197
Thomas Gleixnera924b042006-01-09 20:52:27 -0800198int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
200 /*
201 * You can never reset a CPU clock, but we check for other errors
202 * in the call before failing with EPERM.
203 */
204 int error = check_clock(which_clock);
205 if (error == 0) {
206 error = -EPERM;
207 }
208 return error;
209}
210
211
212/*
213 * Sample a per-thread clock for the given task.
214 */
Thomas Gleixnera924b042006-01-09 20:52:27 -0800215static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 union cpu_time_count *cpu)
217{
218 switch (CPUCLOCK_WHICH(which_clock)) {
219 default:
220 return -EINVAL;
221 case CPUCLOCK_PROF:
222 cpu->cpu = prof_ticks(p);
223 break;
224 case CPUCLOCK_VIRT:
225 cpu->cpu = virt_ticks(p);
226 break;
227 case CPUCLOCK_SCHED:
Hidetoshi Setoc5f8d992009-03-31 16:56:03 +0900228 cpu->sched = task_sched_runtime(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 break;
230 }
231 return 0;
232}
233
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100234void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
235{
236 struct sighand_struct *sighand;
237 struct signal_struct *sig;
238 struct task_struct *t;
239
240 *times = INIT_CPUTIME;
241
242 rcu_read_lock();
243 sighand = rcu_dereference(tsk->sighand);
244 if (!sighand)
245 goto out;
246
247 sig = tsk->signal;
248
249 t = tsk;
250 do {
251 times->utime = cputime_add(times->utime, t->utime);
252 times->stime = cputime_add(times->stime, t->stime);
253 times->sum_exec_runtime += t->se.sum_exec_runtime;
254
255 t = next_thread(t);
256 } while (t != tsk);
257
258 times->utime = cputime_add(times->utime, sig->utime);
259 times->stime = cputime_add(times->stime, sig->stime);
260 times->sum_exec_runtime += sig->sum_sched_runtime;
261out:
262 rcu_read_unlock();
263}
264
Peter Zijlstra4da94d492009-02-11 11:30:27 +0100265static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
266{
267 if (cputime_gt(b->utime, a->utime))
268 a->utime = b->utime;
269
270 if (cputime_gt(b->stime, a->stime))
271 a->stime = b->stime;
272
273 if (b->sum_exec_runtime > a->sum_exec_runtime)
274 a->sum_exec_runtime = b->sum_exec_runtime;
275}
276
277void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
278{
279 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
280 struct task_cputime sum;
281 unsigned long flags;
282
283 spin_lock_irqsave(&cputimer->lock, flags);
284 if (!cputimer->running) {
285 cputimer->running = 1;
286 /*
287 * The POSIX timer interface allows for absolute time expiry
288 * values through the TIMER_ABSTIME flag, therefore we have
289 * to synchronize the timer to the clock every time we start
290 * it.
291 */
292 thread_group_cputime(tsk, &sum);
293 update_gt_cputime(&cputimer->cputime, &sum);
294 }
295 *times = cputimer->cputime;
296 spin_unlock_irqrestore(&cputimer->lock, flags);
297}
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299/*
300 * Sample a process (thread group) clock for the given group_leader task.
301 * Must be called with tasklist_lock held for reading.
302 */
Thomas Gleixnera924b042006-01-09 20:52:27 -0800303static int cpu_clock_sample_group(const clockid_t which_clock,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 struct task_struct *p,
305 union cpu_time_count *cpu)
306{
Frank Mayharbb34d922008-09-12 09:54:39 -0700307 struct task_cputime cputime;
308
Petr Tesarikeccdaea2008-11-24 15:46:31 +0100309 switch (CPUCLOCK_WHICH(which_clock)) {
Frank Mayharbb34d922008-09-12 09:54:39 -0700310 default:
311 return -EINVAL;
312 case CPUCLOCK_PROF:
Hidetoshi Setoc5f8d992009-03-31 16:56:03 +0900313 thread_group_cputime(p, &cputime);
Frank Mayharbb34d922008-09-12 09:54:39 -0700314 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
315 break;
316 case CPUCLOCK_VIRT:
Hidetoshi Setoc5f8d992009-03-31 16:56:03 +0900317 thread_group_cputime(p, &cputime);
Frank Mayharbb34d922008-09-12 09:54:39 -0700318 cpu->cpu = cputime.utime;
319 break;
320 case CPUCLOCK_SCHED:
Hidetoshi Setoc5f8d992009-03-31 16:56:03 +0900321 cpu->sched = thread_group_sched_runtime(p);
Frank Mayharbb34d922008-09-12 09:54:39 -0700322 break;
323 }
324 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325}
326
327
Thomas Gleixnera924b042006-01-09 20:52:27 -0800328int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329{
330 const pid_t pid = CPUCLOCK_PID(which_clock);
331 int error = -EINVAL;
332 union cpu_time_count rtn;
333
334 if (pid == 0) {
335 /*
336 * Special case constant value for our own clocks.
337 * We don't have to do any lookup to find ourselves.
338 */
339 if (CPUCLOCK_PERTHREAD(which_clock)) {
340 /*
341 * Sampling just ourselves we can do with no locking.
342 */
343 error = cpu_clock_sample(which_clock,
344 current, &rtn);
345 } else {
346 read_lock(&tasklist_lock);
347 error = cpu_clock_sample_group(which_clock,
348 current, &rtn);
349 read_unlock(&tasklist_lock);
350 }
351 } else {
352 /*
353 * Find the given PID, and validate that the caller
354 * should be able to see it.
355 */
356 struct task_struct *p;
Paul E. McKenney1f2ea082007-02-16 01:28:22 -0800357 rcu_read_lock();
Pavel Emelyanov8dc86af2008-02-08 04:21:52 -0800358 p = find_task_by_vpid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 if (p) {
360 if (CPUCLOCK_PERTHREAD(which_clock)) {
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -0700361 if (same_thread_group(p, current)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 error = cpu_clock_sample(which_clock,
363 p, &rtn);
364 }
Paul E. McKenney1f2ea082007-02-16 01:28:22 -0800365 } else {
366 read_lock(&tasklist_lock);
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -0700367 if (thread_group_leader(p) && p->signal) {
Paul E. McKenney1f2ea082007-02-16 01:28:22 -0800368 error =
369 cpu_clock_sample_group(which_clock,
370 p, &rtn);
371 }
372 read_unlock(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 }
374 }
Paul E. McKenney1f2ea082007-02-16 01:28:22 -0800375 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 }
377
378 if (error)
379 return error;
380 sample_to_timespec(which_clock, rtn, tp);
381 return 0;
382}
383
384
385/*
386 * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
Stanislaw Gruszkaba5ea952009-11-17 14:14:13 -0800387 * This is called from sys_timer_create() and do_cpu_nanosleep() with the
388 * new timer already all-zeros initialized.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 */
390int posix_cpu_timer_create(struct k_itimer *new_timer)
391{
392 int ret = 0;
393 const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
394 struct task_struct *p;
395
396 if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
397 return -EINVAL;
398
399 INIT_LIST_HEAD(&new_timer->it.cpu.entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
401 read_lock(&tasklist_lock);
402 if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
403 if (pid == 0) {
404 p = current;
405 } else {
Pavel Emelyanov8dc86af2008-02-08 04:21:52 -0800406 p = find_task_by_vpid(pid);
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -0700407 if (p && !same_thread_group(p, current))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 p = NULL;
409 }
410 } else {
411 if (pid == 0) {
412 p = current->group_leader;
413 } else {
Pavel Emelyanov8dc86af2008-02-08 04:21:52 -0800414 p = find_task_by_vpid(pid);
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -0700415 if (p && !thread_group_leader(p))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 p = NULL;
417 }
418 }
419 new_timer->it.cpu.task = p;
420 if (p) {
421 get_task_struct(p);
422 } else {
423 ret = -EINVAL;
424 }
425 read_unlock(&tasklist_lock);
426
427 return ret;
428}
429
430/*
431 * Clean up a CPU-clock timer that is about to be destroyed.
432 * This is called from timer deletion with the timer already locked.
433 * If we return TIMER_RETRY, it's necessary to release the timer's lock
434 * and try again. (This happens when the timer is in the middle of firing.)
435 */
436int posix_cpu_timer_del(struct k_itimer *timer)
437{
438 struct task_struct *p = timer->it.cpu.task;
Oleg Nesterov108150e2005-10-23 20:25:39 +0400439 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
Oleg Nesterov108150e2005-10-23 20:25:39 +0400441 if (likely(p != NULL)) {
Linus Torvalds9465bee2005-10-21 15:36:00 -0700442 read_lock(&tasklist_lock);
443 if (unlikely(p->signal == NULL)) {
444 /*
445 * We raced with the reaping of the task.
446 * The deletion should have cleared us off the list.
447 */
448 BUG_ON(!list_empty(&timer->it.cpu.entry));
449 } else {
Linus Torvalds9465bee2005-10-21 15:36:00 -0700450 spin_lock(&p->sighand->siglock);
Oleg Nesterov108150e2005-10-23 20:25:39 +0400451 if (timer->it.cpu.firing)
452 ret = TIMER_RETRY;
453 else
454 list_del(&timer->it.cpu.entry);
Linus Torvalds9465bee2005-10-21 15:36:00 -0700455 spin_unlock(&p->sighand->siglock);
456 }
457 read_unlock(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458
Oleg Nesterov108150e2005-10-23 20:25:39 +0400459 if (!ret)
460 put_task_struct(p);
461 }
462
463 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464}
465
466/*
467 * Clean out CPU timers still ticking when a thread exited. The task
468 * pointer is cleared, and the expiry time is replaced with the residual
469 * time for later timer_gettime calls to return.
470 * This must be called with the siglock held.
471 */
472static void cleanup_timers(struct list_head *head,
473 cputime_t utime, cputime_t stime,
Ingo Molnar41b86e92007-07-09 18:51:58 +0200474 unsigned long long sum_exec_runtime)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475{
476 struct cpu_timer_list *timer, *next;
477 cputime_t ptime = cputime_add(utime, stime);
478
479 list_for_each_entry_safe(timer, next, head, entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 list_del_init(&timer->entry);
481 if (cputime_lt(timer->expires.cpu, ptime)) {
482 timer->expires.cpu = cputime_zero;
483 } else {
484 timer->expires.cpu = cputime_sub(timer->expires.cpu,
485 ptime);
486 }
487 }
488
489 ++head;
490 list_for_each_entry_safe(timer, next, head, entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 list_del_init(&timer->entry);
492 if (cputime_lt(timer->expires.cpu, utime)) {
493 timer->expires.cpu = cputime_zero;
494 } else {
495 timer->expires.cpu = cputime_sub(timer->expires.cpu,
496 utime);
497 }
498 }
499
500 ++head;
501 list_for_each_entry_safe(timer, next, head, entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 list_del_init(&timer->entry);
Ingo Molnar41b86e92007-07-09 18:51:58 +0200503 if (timer->expires.sched < sum_exec_runtime) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 timer->expires.sched = 0;
505 } else {
Ingo Molnar41b86e92007-07-09 18:51:58 +0200506 timer->expires.sched -= sum_exec_runtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 }
508 }
509}
510
511/*
512 * These are both called with the siglock held, when the current thread
513 * is being reaped. When the final (leader) thread in the group is reaped,
514 * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
515 */
516void posix_cpu_timers_exit(struct task_struct *tsk)
517{
518 cleanup_timers(tsk->cpu_timers,
Ingo Molnar41b86e92007-07-09 18:51:58 +0200519 tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
521}
522void posix_cpu_timers_exit_group(struct task_struct *tsk)
523{
Stanislaw Gruszka17d42c12009-08-06 16:03:30 -0700524 struct signal_struct *const sig = tsk->signal;
Frank Mayharf06febc2008-09-12 09:54:39 -0700525
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 cleanup_timers(tsk->signal->cpu_timers,
Stanislaw Gruszka17d42c12009-08-06 16:03:30 -0700527 cputime_add(tsk->utime, sig->utime),
528 cputime_add(tsk->stime, sig->stime),
529 tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530}
531
532static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
533{
534 /*
535 * That's all for this thread or process.
536 * We leave our residual in expires to be reported.
537 */
538 put_task_struct(timer->it.cpu.task);
539 timer->it.cpu.task = NULL;
540 timer->it.cpu.expires = cpu_time_sub(timer->it_clock,
541 timer->it.cpu.expires,
542 now);
543}
544
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200545static inline int expires_gt(cputime_t expires, cputime_t new_exp)
546{
547 return cputime_eq(expires, cputime_zero) ||
548 cputime_gt(expires, new_exp);
549}
550
551static inline int expires_le(cputime_t expires, cputime_t new_exp)
552{
553 return !cputime_eq(expires, cputime_zero) &&
554 cputime_le(expires, new_exp);
555}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556/*
557 * Insert the timer on the appropriate list before any timers that
558 * expire later. This must be called with the tasklist_lock held
559 * for reading, and interrupts disabled.
560 */
561static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
562{
563 struct task_struct *p = timer->it.cpu.task;
564 struct list_head *head, *listpos;
565 struct cpu_timer_list *const nt = &timer->it.cpu;
566 struct cpu_timer_list *next;
567 unsigned long i;
568
569 head = (CPUCLOCK_PERTHREAD(timer->it_clock) ?
570 p->cpu_timers : p->signal->cpu_timers);
571 head += CPUCLOCK_WHICH(timer->it_clock);
572
573 BUG_ON(!irqs_disabled());
574 spin_lock(&p->sighand->siglock);
575
576 listpos = head;
577 if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
578 list_for_each_entry(next, head, entry) {
Linus Torvalds70ab81c2005-10-26 11:23:06 -0700579 if (next->expires.sched > nt->expires.sched)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 break;
Linus Torvalds70ab81c2005-10-26 11:23:06 -0700581 listpos = &next->entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 }
583 } else {
584 list_for_each_entry(next, head, entry) {
Linus Torvalds70ab81c2005-10-26 11:23:06 -0700585 if (cputime_gt(next->expires.cpu, nt->expires.cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 break;
Linus Torvalds70ab81c2005-10-26 11:23:06 -0700587 listpos = &next->entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 }
589 }
590 list_add(&nt->entry, listpos);
591
592 if (listpos == head) {
593 /*
594 * We are the new earliest-expiring timer.
595 * If we are a thread timer, there can always
596 * be a process timer telling us to stop earlier.
597 */
598
599 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200600 union cpu_time_count *exp = &nt->expires;
601
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 switch (CPUCLOCK_WHICH(timer->it_clock)) {
603 default:
604 BUG();
605 case CPUCLOCK_PROF:
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200606 if (expires_gt(p->cputime_expires.prof_exp,
607 exp->cpu))
608 p->cputime_expires.prof_exp = exp->cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 break;
610 case CPUCLOCK_VIRT:
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200611 if (expires_gt(p->cputime_expires.virt_exp,
612 exp->cpu))
613 p->cputime_expires.virt_exp = exp->cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 break;
615 case CPUCLOCK_SCHED:
Frank Mayharf06febc2008-09-12 09:54:39 -0700616 if (p->cputime_expires.sched_exp == 0 ||
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200617 p->cputime_expires.sched_exp > exp->sched)
Frank Mayharf06febc2008-09-12 09:54:39 -0700618 p->cputime_expires.sched_exp =
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200619 exp->sched;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 break;
621 }
622 } else {
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200623 struct signal_struct *const sig = p->signal;
624 union cpu_time_count *exp = &timer->it.cpu.expires;
625
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 /*
Frank Mayharf06febc2008-09-12 09:54:39 -0700627 * For a process timer, set the cached expiration time.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 */
629 switch (CPUCLOCK_WHICH(timer->it_clock)) {
630 default:
631 BUG();
632 case CPUCLOCK_VIRT:
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200633 if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200634 exp->cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 break;
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200636 sig->cputime_expires.virt_exp = exp->cpu;
Frank Mayharf06febc2008-09-12 09:54:39 -0700637 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 case CPUCLOCK_PROF:
Stanislaw Gruszkad1e3b6d2009-07-29 12:15:28 +0200639 if (expires_le(sig->it[CPUCLOCK_PROF].expires,
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200640 exp->cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 break;
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200642 i = sig->rlim[RLIMIT_CPU].rlim_cur;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 if (i != RLIM_INFINITY &&
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200644 i <= cputime_to_secs(exp->cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 break;
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200646 sig->cputime_expires.prof_exp = exp->cpu;
Frank Mayharf06febc2008-09-12 09:54:39 -0700647 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 case CPUCLOCK_SCHED:
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +0200649 sig->cputime_expires.sched_exp = exp->sched;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 break;
651 }
652 }
653 }
654
655 spin_unlock(&p->sighand->siglock);
656}
657
658/*
659 * The timer is locked, fire it and arrange for its reload.
660 */
661static void cpu_timer_fire(struct k_itimer *timer)
662{
663 if (unlikely(timer->sigq == NULL)) {
664 /*
665 * This a special case for clock_nanosleep,
666 * not a normal timer from sys_timer_create.
667 */
668 wake_up_process(timer->it_process);
669 timer->it.cpu.expires.sched = 0;
670 } else if (timer->it.cpu.incr.sched == 0) {
671 /*
672 * One-shot timer. Clear it as soon as it's fired.
673 */
674 posix_timer_event(timer, 0);
675 timer->it.cpu.expires.sched = 0;
676 } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
677 /*
678 * The signal did not get queued because the signal
679 * was ignored, so we won't get any callback to
680 * reload the timer. But we need to keep it
681 * ticking in case the signal is deliverable next time.
682 */
683 posix_cpu_timer_schedule(timer);
684 }
685}
686
687/*
Peter Zijlstra3997ad32009-02-12 15:00:52 +0100688 * Sample a process (thread group) timer for the given group_leader task.
689 * Must be called with tasklist_lock held for reading.
690 */
691static int cpu_timer_sample_group(const clockid_t which_clock,
692 struct task_struct *p,
693 union cpu_time_count *cpu)
694{
695 struct task_cputime cputime;
696
697 thread_group_cputimer(p, &cputime);
698 switch (CPUCLOCK_WHICH(which_clock)) {
699 default:
700 return -EINVAL;
701 case CPUCLOCK_PROF:
702 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
703 break;
704 case CPUCLOCK_VIRT:
705 cpu->cpu = cputime.utime;
706 break;
707 case CPUCLOCK_SCHED:
708 cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
709 break;
710 }
711 return 0;
712}
713
714/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 * Guts of sys_timer_settime for CPU timers.
716 * This is called with the timer locked and interrupts disabled.
717 * If we return TIMER_RETRY, it's necessary to release the timer's lock
718 * and try again. (This happens when the timer is in the middle of firing.)
719 */
720int posix_cpu_timer_set(struct k_itimer *timer, int flags,
721 struct itimerspec *new, struct itimerspec *old)
722{
723 struct task_struct *p = timer->it.cpu.task;
724 union cpu_time_count old_expires, new_expires, val;
725 int ret;
726
727 if (unlikely(p == NULL)) {
728 /*
729 * Timer refers to a dead task's clock.
730 */
731 return -ESRCH;
732 }
733
734 new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
735
736 read_lock(&tasklist_lock);
737 /*
738 * We need the tasklist_lock to protect against reaping that
739 * clears p->signal. If p has just been reaped, we can no
740 * longer get any information about it at all.
741 */
742 if (unlikely(p->signal == NULL)) {
743 read_unlock(&tasklist_lock);
744 put_task_struct(p);
745 timer->it.cpu.task = NULL;
746 return -ESRCH;
747 }
748
749 /*
750 * Disarm any old timer after extracting its expiry time.
751 */
752 BUG_ON(!irqs_disabled());
Oleg Nesterova69ac4a2005-10-24 18:29:58 +0400753
754 ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 spin_lock(&p->sighand->siglock);
756 old_expires = timer->it.cpu.expires;
Oleg Nesterova69ac4a2005-10-24 18:29:58 +0400757 if (unlikely(timer->it.cpu.firing)) {
758 timer->it.cpu.firing = -1;
759 ret = TIMER_RETRY;
760 } else
761 list_del_init(&timer->it.cpu.entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 spin_unlock(&p->sighand->siglock);
763
764 /*
765 * We need to sample the current value to convert the new
766 * value from to relative and absolute, and to convert the
767 * old value from absolute to relative. To set a process
768 * timer, we need a sample to balance the thread expiry
769 * times (in arm_timer). With an absolute time, we must
770 * check if it's already passed. In short, we need a sample.
771 */
772 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
773 cpu_clock_sample(timer->it_clock, p, &val);
774 } else {
Peter Zijlstra3997ad32009-02-12 15:00:52 +0100775 cpu_timer_sample_group(timer->it_clock, p, &val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 }
777
778 if (old) {
779 if (old_expires.sched == 0) {
780 old->it_value.tv_sec = 0;
781 old->it_value.tv_nsec = 0;
782 } else {
783 /*
784 * Update the timer in case it has
785 * overrun already. If it has,
786 * we'll report it as having overrun
787 * and with the next reloaded timer
788 * already ticking, though we are
789 * swallowing that pending
790 * notification here to install the
791 * new setting.
792 */
793 bump_cpu_timer(timer, val);
794 if (cpu_time_before(timer->it_clock, val,
795 timer->it.cpu.expires)) {
796 old_expires = cpu_time_sub(
797 timer->it_clock,
798 timer->it.cpu.expires, val);
799 sample_to_timespec(timer->it_clock,
800 old_expires,
801 &old->it_value);
802 } else {
803 old->it_value.tv_nsec = 1;
804 old->it_value.tv_sec = 0;
805 }
806 }
807 }
808
Oleg Nesterova69ac4a2005-10-24 18:29:58 +0400809 if (unlikely(ret)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 /*
811 * We are colliding with the timer actually firing.
812 * Punt after filling in the timer's old value, and
813 * disable this firing since we are already reporting
814 * it as an overrun (thanks to bump_cpu_timer above).
815 */
816 read_unlock(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 goto out;
818 }
819
820 if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) {
821 cpu_time_add(timer->it_clock, &new_expires, val);
822 }
823
824 /*
825 * Install the new expiry time (or zero).
826 * For a timer with no notification action, we don't actually
827 * arm the timer (we'll just fake it for timer_gettime).
828 */
829 timer->it.cpu.expires = new_expires;
830 if (new_expires.sched != 0 &&
831 (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE &&
832 cpu_time_before(timer->it_clock, val, new_expires)) {
833 arm_timer(timer, val);
834 }
835
836 read_unlock(&tasklist_lock);
837
838 /*
839 * Install the new reload setting, and
840 * set up the signal and overrun bookkeeping.
841 */
842 timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
843 &new->it_interval);
844
845 /*
846 * This acts as a modification timestamp for the timer,
847 * so any automatic reload attempt will punt on seeing
848 * that we have reset the timer manually.
849 */
850 timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
851 ~REQUEUE_PENDING;
852 timer->it_overrun_last = 0;
853 timer->it_overrun = -1;
854
855 if (new_expires.sched != 0 &&
856 (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE &&
857 !cpu_time_before(timer->it_clock, val, new_expires)) {
858 /*
859 * The designated time already passed, so we notify
860 * immediately, even if the thread never runs to
861 * accumulate more time on this clock.
862 */
863 cpu_timer_fire(timer);
864 }
865
866 ret = 0;
867 out:
868 if (old) {
869 sample_to_timespec(timer->it_clock,
870 timer->it.cpu.incr, &old->it_interval);
871 }
872 return ret;
873}
874
875void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
876{
877 union cpu_time_count now;
878 struct task_struct *p = timer->it.cpu.task;
879 int clear_dead;
880
881 /*
882 * Easy part: convert the reload time.
883 */
884 sample_to_timespec(timer->it_clock,
885 timer->it.cpu.incr, &itp->it_interval);
886
887 if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */
888 itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
889 return;
890 }
891
892 if (unlikely(p == NULL)) {
893 /*
894 * This task already died and the timer will never fire.
895 * In this case, expires is actually the dead value.
896 */
897 dead:
898 sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
899 &itp->it_value);
900 return;
901 }
902
903 /*
904 * Sample the clock to take the difference with the expiry time.
905 */
906 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
907 cpu_clock_sample(timer->it_clock, p, &now);
908 clear_dead = p->exit_state;
909 } else {
910 read_lock(&tasklist_lock);
911 if (unlikely(p->signal == NULL)) {
912 /*
913 * The process has been reaped.
914 * We can't even collect a sample any more.
915 * Call the timer disarmed, nothing else to do.
916 */
917 put_task_struct(p);
918 timer->it.cpu.task = NULL;
919 timer->it.cpu.expires.sched = 0;
920 read_unlock(&tasklist_lock);
921 goto dead;
922 } else {
Peter Zijlstra3997ad32009-02-12 15:00:52 +0100923 cpu_timer_sample_group(timer->it_clock, p, &now);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 clear_dead = (unlikely(p->exit_state) &&
925 thread_group_empty(p));
926 }
927 read_unlock(&tasklist_lock);
928 }
929
930 if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
931 if (timer->it.cpu.incr.sched == 0 &&
932 cpu_time_before(timer->it_clock,
933 timer->it.cpu.expires, now)) {
934 /*
935 * Do-nothing timer expired and has no reload,
936 * so it's as if it was never set.
937 */
938 timer->it.cpu.expires.sched = 0;
939 itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
940 return;
941 }
942 /*
943 * Account for any expirations and reloads that should
944 * have happened.
945 */
946 bump_cpu_timer(timer, now);
947 }
948
949 if (unlikely(clear_dead)) {
950 /*
951 * We've noticed that the thread is dead, but
952 * not yet reaped. Take this opportunity to
953 * drop our task ref.
954 */
955 clear_dead_task(timer, now);
956 goto dead;
957 }
958
959 if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
960 sample_to_timespec(timer->it_clock,
961 cpu_time_sub(timer->it_clock,
962 timer->it.cpu.expires, now),
963 &itp->it_value);
964 } else {
965 /*
966 * The timer should have expired already, but the firing
967 * hasn't taken place yet. Say it's just about to expire.
968 */
969 itp->it_value.tv_nsec = 1;
970 itp->it_value.tv_sec = 0;
971 }
972}
973
974/*
975 * Check for any per-thread CPU timers that have fired and move them off
976 * the tsk->cpu_timers[N] list onto the firing list. Here we update the
977 * tsk->it_*_expires values to reflect the remaining thread CPU timers.
978 */
979static void check_thread_timers(struct task_struct *tsk,
980 struct list_head *firing)
981{
Linus Torvaldse80eda92005-10-23 10:02:50 -0700982 int maxfire;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 struct list_head *timers = tsk->cpu_timers;
Peter Zijlstra78f2c7d2008-01-25 21:08:27 +0100984 struct signal_struct *const sig = tsk->signal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
Linus Torvaldse80eda92005-10-23 10:02:50 -0700986 maxfire = 20;
Frank Mayharf06febc2008-09-12 09:54:39 -0700987 tsk->cputime_expires.prof_exp = cputime_zero;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 while (!list_empty(timers)) {
Pavel Emelianovb5e61812007-05-08 00:30:19 -0700989 struct cpu_timer_list *t = list_first_entry(timers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 struct cpu_timer_list,
991 entry);
Linus Torvaldse80eda92005-10-23 10:02:50 -0700992 if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
Frank Mayharf06febc2008-09-12 09:54:39 -0700993 tsk->cputime_expires.prof_exp = t->expires.cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 break;
995 }
996 t->firing = 1;
997 list_move_tail(&t->entry, firing);
998 }
999
1000 ++timers;
Linus Torvaldse80eda92005-10-23 10:02:50 -07001001 maxfire = 20;
Frank Mayharf06febc2008-09-12 09:54:39 -07001002 tsk->cputime_expires.virt_exp = cputime_zero;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 while (!list_empty(timers)) {
Pavel Emelianovb5e61812007-05-08 00:30:19 -07001004 struct cpu_timer_list *t = list_first_entry(timers,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 struct cpu_timer_list,
1006 entry);
Linus Torvaldse80eda92005-10-23 10:02:50 -07001007 if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
Frank Mayharf06febc2008-09-12 09:54:39 -07001008 tsk->cputime_expires.virt_exp = t->expires.cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 break;
1010 }
1011 t->firing = 1;
1012 list_move_tail(&t->entry, firing);
1013 }
1014
1015 ++timers;
Linus Torvaldse80eda92005-10-23 10:02:50 -07001016 maxfire = 20;
Frank Mayharf06febc2008-09-12 09:54:39 -07001017 tsk->cputime_expires.sched_exp = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 while (!list_empty(timers)) {
Pavel Emelianovb5e61812007-05-08 00:30:19 -07001019 struct cpu_timer_list *t = list_first_entry(timers,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 struct cpu_timer_list,
1021 entry);
Ingo Molnar41b86e92007-07-09 18:51:58 +02001022 if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
Frank Mayharf06febc2008-09-12 09:54:39 -07001023 tsk->cputime_expires.sched_exp = t->expires.sched;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 break;
1025 }
1026 t->firing = 1;
1027 list_move_tail(&t->entry, firing);
1028 }
Peter Zijlstra78f2c7d2008-01-25 21:08:27 +01001029
1030 /*
1031 * Check for the special case thread timers.
1032 */
1033 if (sig->rlim[RLIMIT_RTTIME].rlim_cur != RLIM_INFINITY) {
1034 unsigned long hard = sig->rlim[RLIMIT_RTTIME].rlim_max;
1035 unsigned long *soft = &sig->rlim[RLIMIT_RTTIME].rlim_cur;
1036
Peter Zijlstra5a52dd52008-01-25 21:08:32 +01001037 if (hard != RLIM_INFINITY &&
1038 tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
Peter Zijlstra78f2c7d2008-01-25 21:08:27 +01001039 /*
1040 * At the hard limit, we just die.
1041 * No need to calculate anything else now.
1042 */
1043 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
1044 return;
1045 }
1046 if (tsk->rt.timeout > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) {
1047 /*
1048 * At the soft limit, send a SIGXCPU every second.
1049 */
1050 if (sig->rlim[RLIMIT_RTTIME].rlim_cur
1051 < sig->rlim[RLIMIT_RTTIME].rlim_max) {
1052 sig->rlim[RLIMIT_RTTIME].rlim_cur +=
1053 USEC_PER_SEC;
1054 }
Hiroshi Shimamoto81d50bb2008-05-15 19:42:49 -07001055 printk(KERN_INFO
1056 "RT Watchdog Timeout: %s[%d]\n",
1057 tsk->comm, task_pid_nr(tsk));
Peter Zijlstra78f2c7d2008-01-25 21:08:27 +01001058 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
1059 }
1060 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061}
1062
Peter Zijlstra3fccfd62009-02-10 16:37:31 +01001063static void stop_process_timers(struct task_struct *tsk)
1064{
1065 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
1066 unsigned long flags;
1067
1068 if (!cputimer->running)
1069 return;
1070
1071 spin_lock_irqsave(&cputimer->lock, flags);
1072 cputimer->running = 0;
1073 spin_unlock_irqrestore(&cputimer->lock, flags);
1074}
1075
Stanislaw Gruszka8356b5f2009-07-29 12:15:27 +02001076static u32 onecputick;
1077
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +02001078static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
1079 cputime_t *expires, cputime_t cur_time, int signo)
1080{
1081 if (cputime_eq(it->expires, cputime_zero))
1082 return;
1083
1084 if (cputime_ge(cur_time, it->expires)) {
Stanislaw Gruszka8356b5f2009-07-29 12:15:27 +02001085 if (!cputime_eq(it->incr, cputime_zero)) {
1086 it->expires = cputime_add(it->expires, it->incr);
1087 it->error += it->incr_error;
1088 if (it->error >= onecputick) {
1089 it->expires = cputime_sub(it->expires,
Stanislaw Gruszkaa42548a2009-07-29 12:15:29 +02001090 cputime_one_jiffy);
Stanislaw Gruszka8356b5f2009-07-29 12:15:27 +02001091 it->error -= onecputick;
1092 }
Xiao Guangrong3f0a5252009-08-10 10:52:30 +08001093 } else {
Stanislaw Gruszka8356b5f2009-07-29 12:15:27 +02001094 it->expires = cputime_zero;
Xiao Guangrong3f0a5252009-08-10 10:52:30 +08001095 }
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +02001096
Xiao Guangrong3f0a5252009-08-10 10:52:30 +08001097 trace_itimer_expire(signo == SIGPROF ?
1098 ITIMER_PROF : ITIMER_VIRTUAL,
1099 tsk->signal->leader_pid, cur_time);
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +02001100 __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
1101 }
1102
1103 if (!cputime_eq(it->expires, cputime_zero) &&
1104 (cputime_eq(*expires, cputime_zero) ||
1105 cputime_lt(it->expires, *expires))) {
1106 *expires = it->expires;
1107 }
1108}
1109
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110/*
1111 * Check for any per-thread CPU timers that have fired and move them
1112 * off the tsk->*_timers list onto the firing list. Per-thread timers
1113 * have already been taken off.
1114 */
1115static void check_process_timers(struct task_struct *tsk,
1116 struct list_head *firing)
1117{
Linus Torvaldse80eda92005-10-23 10:02:50 -07001118 int maxfire;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 struct signal_struct *const sig = tsk->signal;
Frank Mayharf06febc2008-09-12 09:54:39 -07001120 cputime_t utime, ptime, virt_expires, prof_expires;
Ingo Molnar41b86e92007-07-09 18:51:58 +02001121 unsigned long long sum_sched_runtime, sched_expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 struct list_head *timers = sig->cpu_timers;
Frank Mayharf06febc2008-09-12 09:54:39 -07001123 struct task_cputime cputime;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124
1125 /*
1126 * Don't sample the current process CPU clocks if there are no timers.
1127 */
1128 if (list_empty(&timers[CPUCLOCK_PROF]) &&
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +02001129 cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
1131 list_empty(&timers[CPUCLOCK_VIRT]) &&
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +02001132 cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01001133 list_empty(&timers[CPUCLOCK_SCHED])) {
1134 stop_process_timers(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 return;
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01001136 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137
1138 /*
1139 * Collect the current process totals.
1140 */
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01001141 thread_group_cputimer(tsk, &cputime);
Frank Mayharf06febc2008-09-12 09:54:39 -07001142 utime = cputime.utime;
1143 ptime = cputime_add(utime, cputime.stime);
1144 sum_sched_runtime = cputime.sum_exec_runtime;
Linus Torvaldse80eda92005-10-23 10:02:50 -07001145 maxfire = 20;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 prof_expires = cputime_zero;
1147 while (!list_empty(timers)) {
WANG Congee7dd202008-04-04 20:54:10 +02001148 struct cpu_timer_list *tl = list_first_entry(timers,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 struct cpu_timer_list,
1150 entry);
WANG Congee7dd202008-04-04 20:54:10 +02001151 if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
1152 prof_expires = tl->expires.cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 break;
1154 }
WANG Congee7dd202008-04-04 20:54:10 +02001155 tl->firing = 1;
1156 list_move_tail(&tl->entry, firing);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157 }
1158
1159 ++timers;
Linus Torvaldse80eda92005-10-23 10:02:50 -07001160 maxfire = 20;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 virt_expires = cputime_zero;
1162 while (!list_empty(timers)) {
WANG Congee7dd202008-04-04 20:54:10 +02001163 struct cpu_timer_list *tl = list_first_entry(timers,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 struct cpu_timer_list,
1165 entry);
WANG Congee7dd202008-04-04 20:54:10 +02001166 if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
1167 virt_expires = tl->expires.cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168 break;
1169 }
WANG Congee7dd202008-04-04 20:54:10 +02001170 tl->firing = 1;
1171 list_move_tail(&tl->entry, firing);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 }
1173
1174 ++timers;
Linus Torvaldse80eda92005-10-23 10:02:50 -07001175 maxfire = 20;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 sched_expires = 0;
1177 while (!list_empty(timers)) {
WANG Congee7dd202008-04-04 20:54:10 +02001178 struct cpu_timer_list *tl = list_first_entry(timers,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 struct cpu_timer_list,
1180 entry);
WANG Congee7dd202008-04-04 20:54:10 +02001181 if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
1182 sched_expires = tl->expires.sched;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 break;
1184 }
WANG Congee7dd202008-04-04 20:54:10 +02001185 tl->firing = 1;
1186 list_move_tail(&tl->entry, firing);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 }
1188
1189 /*
1190 * Check for the special case process timers.
1191 */
Stanislaw Gruszka42c4ab42009-07-29 12:15:26 +02001192 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
1193 SIGPROF);
1194 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
1195 SIGVTALRM);
1196
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1198 unsigned long psecs = cputime_to_secs(ptime);
1199 cputime_t x;
1200 if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) {
1201 /*
1202 * At the hard limit, we just die.
1203 * No need to calculate anything else now.
1204 */
1205 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
1206 return;
1207 }
1208 if (psecs >= sig->rlim[RLIMIT_CPU].rlim_cur) {
1209 /*
1210 * At the soft limit, send a SIGXCPU every second.
1211 */
1212 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
1213 if (sig->rlim[RLIMIT_CPU].rlim_cur
1214 < sig->rlim[RLIMIT_CPU].rlim_max) {
1215 sig->rlim[RLIMIT_CPU].rlim_cur++;
1216 }
1217 }
1218 x = secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
1219 if (cputime_eq(prof_expires, cputime_zero) ||
1220 cputime_lt(x, prof_expires)) {
1221 prof_expires = x;
1222 }
1223 }
1224
Frank Mayharf06febc2008-09-12 09:54:39 -07001225 if (!cputime_eq(prof_expires, cputime_zero) &&
1226 (cputime_eq(sig->cputime_expires.prof_exp, cputime_zero) ||
1227 cputime_gt(sig->cputime_expires.prof_exp, prof_expires)))
1228 sig->cputime_expires.prof_exp = prof_expires;
1229 if (!cputime_eq(virt_expires, cputime_zero) &&
1230 (cputime_eq(sig->cputime_expires.virt_exp, cputime_zero) ||
1231 cputime_gt(sig->cputime_expires.virt_exp, virt_expires)))
1232 sig->cputime_expires.virt_exp = virt_expires;
1233 if (sched_expires != 0 &&
1234 (sig->cputime_expires.sched_exp == 0 ||
1235 sig->cputime_expires.sched_exp > sched_expires))
1236 sig->cputime_expires.sched_exp = sched_expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237}
1238
1239/*
1240 * This is called from the signal code (via do_schedule_next_timer)
1241 * when the last timer signal was delivered and we have to reload the timer.
1242 */
1243void posix_cpu_timer_schedule(struct k_itimer *timer)
1244{
1245 struct task_struct *p = timer->it.cpu.task;
1246 union cpu_time_count now;
1247
1248 if (unlikely(p == NULL))
1249 /*
1250 * The task was cleaned up already, no future firings.
1251 */
Roland McGrath708f4302005-10-30 15:03:13 -08001252 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253
1254 /*
1255 * Fetch the current sample and update the timer's expiry time.
1256 */
1257 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
1258 cpu_clock_sample(timer->it_clock, p, &now);
1259 bump_cpu_timer(timer, now);
1260 if (unlikely(p->exit_state)) {
1261 clear_dead_task(timer, now);
Roland McGrath708f4302005-10-30 15:03:13 -08001262 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 }
1264 read_lock(&tasklist_lock); /* arm_timer needs it. */
1265 } else {
1266 read_lock(&tasklist_lock);
1267 if (unlikely(p->signal == NULL)) {
1268 /*
1269 * The process has been reaped.
1270 * We can't even collect a sample any more.
1271 */
1272 put_task_struct(p);
1273 timer->it.cpu.task = p = NULL;
1274 timer->it.cpu.expires.sched = 0;
Roland McGrath708f4302005-10-30 15:03:13 -08001275 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
1277 /*
1278 * We've noticed that the thread is dead, but
1279 * not yet reaped. Take this opportunity to
1280 * drop our task ref.
1281 */
1282 clear_dead_task(timer, now);
Roland McGrath708f4302005-10-30 15:03:13 -08001283 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284 }
Peter Zijlstra3997ad32009-02-12 15:00:52 +01001285 cpu_timer_sample_group(timer->it_clock, p, &now);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 bump_cpu_timer(timer, now);
1287 /* Leave the tasklist_lock locked for the call below. */
1288 }
1289
1290 /*
1291 * Now re-arm for the new expiry time.
1292 */
1293 arm_timer(timer, now);
1294
Roland McGrath708f4302005-10-30 15:03:13 -08001295out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 read_unlock(&tasklist_lock);
Roland McGrath708f4302005-10-30 15:03:13 -08001297
1298out:
1299 timer->it_overrun_last = timer->it_overrun;
1300 timer->it_overrun = -1;
1301 ++timer->it_requeue_pending;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302}
1303
Frank Mayharf06febc2008-09-12 09:54:39 -07001304/**
1305 * task_cputime_zero - Check a task_cputime struct for all zero fields.
1306 *
1307 * @cputime: The struct to compare.
1308 *
1309 * Checks @cputime to see if all fields are zero. Returns true if all fields
1310 * are zero, false if any field is nonzero.
1311 */
1312static inline int task_cputime_zero(const struct task_cputime *cputime)
1313{
1314 if (cputime_eq(cputime->utime, cputime_zero) &&
1315 cputime_eq(cputime->stime, cputime_zero) &&
1316 cputime->sum_exec_runtime == 0)
1317 return 1;
1318 return 0;
1319}
1320
1321/**
1322 * task_cputime_expired - Compare two task_cputime entities.
1323 *
1324 * @sample: The task_cputime structure to be checked for expiration.
1325 * @expires: Expiration times, against which @sample will be checked.
1326 *
1327 * Checks @sample against @expires to see if any field of @sample has expired.
1328 * Returns true if any field of the former is greater than the corresponding
1329 * field of the latter if the latter field is set. Otherwise returns false.
1330 */
1331static inline int task_cputime_expired(const struct task_cputime *sample,
1332 const struct task_cputime *expires)
1333{
1334 if (!cputime_eq(expires->utime, cputime_zero) &&
1335 cputime_ge(sample->utime, expires->utime))
1336 return 1;
1337 if (!cputime_eq(expires->stime, cputime_zero) &&
1338 cputime_ge(cputime_add(sample->utime, sample->stime),
1339 expires->stime))
1340 return 1;
1341 if (expires->sum_exec_runtime != 0 &&
1342 sample->sum_exec_runtime >= expires->sum_exec_runtime)
1343 return 1;
1344 return 0;
1345}
1346
1347/**
1348 * fastpath_timer_check - POSIX CPU timers fast path.
1349 *
1350 * @tsk: The task (thread) being checked.
Frank Mayharf06febc2008-09-12 09:54:39 -07001351 *
Frank Mayharbb34d922008-09-12 09:54:39 -07001352 * Check the task and thread group timers. If both are zero (there are no
1353 * timers set) return false. Otherwise snapshot the task and thread group
1354 * timers and compare them with the corresponding expiration times. Return
1355 * true if a timer has expired, else return false.
Frank Mayharf06febc2008-09-12 09:54:39 -07001356 */
Frank Mayharbb34d922008-09-12 09:54:39 -07001357static inline int fastpath_timer_check(struct task_struct *tsk)
Frank Mayharf06febc2008-09-12 09:54:39 -07001358{
Oleg Nesterovad133ba2008-11-17 15:39:47 +01001359 struct signal_struct *sig;
Frank Mayharf06febc2008-09-12 09:54:39 -07001360
Oleg Nesterovad133ba2008-11-17 15:39:47 +01001361 /* tsk == current, ensure it is safe to use ->signal/sighand */
1362 if (unlikely(tsk->exit_state))
Frank Mayharf06febc2008-09-12 09:54:39 -07001363 return 0;
Frank Mayharbb34d922008-09-12 09:54:39 -07001364
1365 if (!task_cputime_zero(&tsk->cputime_expires)) {
1366 struct task_cputime task_sample = {
1367 .utime = tsk->utime,
1368 .stime = tsk->stime,
1369 .sum_exec_runtime = tsk->se.sum_exec_runtime
1370 };
1371
1372 if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
1373 return 1;
1374 }
Oleg Nesterovad133ba2008-11-17 15:39:47 +01001375
1376 sig = tsk->signal;
Frank Mayharbb34d922008-09-12 09:54:39 -07001377 if (!task_cputime_zero(&sig->cputime_expires)) {
1378 struct task_cputime group_sample;
1379
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01001380 thread_group_cputimer(tsk, &group_sample);
Frank Mayharbb34d922008-09-12 09:54:39 -07001381 if (task_cputime_expired(&group_sample, &sig->cputime_expires))
1382 return 1;
1383 }
Oleg Nesterov37bebc72009-03-23 20:34:11 +01001384
1385 return sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY;
Frank Mayharf06febc2008-09-12 09:54:39 -07001386}
1387
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388/*
1389 * This is called from the timer interrupt handler. The irq handler has
1390 * already updated our counts. We need to check if any timers fire now.
1391 * Interrupts are disabled.
1392 */
1393void run_posix_cpu_timers(struct task_struct *tsk)
1394{
1395 LIST_HEAD(firing);
1396 struct k_itimer *timer, *next;
1397
1398 BUG_ON(!irqs_disabled());
1399
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 /*
Frank Mayharf06febc2008-09-12 09:54:39 -07001401 * The fast path checks that there are no expired thread or thread
Frank Mayharbb34d922008-09-12 09:54:39 -07001402 * group timers. If that's so, just return.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 */
Frank Mayharbb34d922008-09-12 09:54:39 -07001404 if (!fastpath_timer_check(tsk))
Frank Mayharf06febc2008-09-12 09:54:39 -07001405 return;
Ingo Molnar5ce73a42008-09-14 17:11:46 +02001406
Frank Mayharbb34d922008-09-12 09:54:39 -07001407 spin_lock(&tsk->sighand->siglock);
1408 /*
1409 * Here we take off tsk->signal->cpu_timers[N] and
1410 * tsk->cpu_timers[N] all the timers that are firing, and
1411 * put them on the firing list.
1412 */
1413 check_thread_timers(tsk, &firing);
1414 check_process_timers(tsk, &firing);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415
Frank Mayharbb34d922008-09-12 09:54:39 -07001416 /*
1417 * We must release these locks before taking any timer's lock.
1418 * There is a potential race with timer deletion here, as the
1419 * siglock now protects our private firing list. We have set
1420 * the firing flag in each timer, so that a deletion attempt
1421 * that gets the timer lock before we do will give it up and
1422 * spin until we've taken care of that timer below.
1423 */
1424 spin_unlock(&tsk->sighand->siglock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425
1426 /*
1427 * Now that all the timers on our list have the firing flag,
1428 * noone will touch their list entries but us. We'll take
1429 * each timer's lock before clearing its firing flag, so no
1430 * timer call will interfere.
1431 */
1432 list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
H Hartley Sweeten6e85c5b2009-04-29 19:14:32 -04001433 int cpu_firing;
1434
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435 spin_lock(&timer->it_lock);
1436 list_del_init(&timer->it.cpu.entry);
H Hartley Sweeten6e85c5b2009-04-29 19:14:32 -04001437 cpu_firing = timer->it.cpu.firing;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 timer->it.cpu.firing = 0;
1439 /*
1440 * The firing flag is -1 if we collided with a reset
1441 * of the timer, which already reported this
1442 * almost-firing as an overrun. So don't generate an event.
1443 */
H Hartley Sweeten6e85c5b2009-04-29 19:14:32 -04001444 if (likely(cpu_firing >= 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 cpu_timer_fire(timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446 spin_unlock(&timer->it_lock);
1447 }
1448}
1449
1450/*
1451 * Set one of the process-wide special case CPU timers.
Frank Mayharf06febc2008-09-12 09:54:39 -07001452 * The tsk->sighand->siglock must be held by the caller.
1453 * The *newval argument is relative and we update it to be absolute, *oldval
1454 * is absolute and we update it to be relative.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001455 */
1456void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
1457 cputime_t *newval, cputime_t *oldval)
1458{
1459 union cpu_time_count now;
1460 struct list_head *head;
1461
1462 BUG_ON(clock_idx == CPUCLOCK_SCHED);
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01001463 cpu_timer_sample_group(clock_idx, tsk, &now);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464
1465 if (oldval) {
1466 if (!cputime_eq(*oldval, cputime_zero)) {
1467 if (cputime_le(*oldval, now.cpu)) {
1468 /* Just about to fire. */
Stanislaw Gruszkaa42548a2009-07-29 12:15:29 +02001469 *oldval = cputime_one_jiffy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001470 } else {
1471 *oldval = cputime_sub(*oldval, now.cpu);
1472 }
1473 }
1474
1475 if (cputime_eq(*newval, cputime_zero))
1476 return;
1477 *newval = cputime_add(*newval, now.cpu);
1478
1479 /*
1480 * If the RLIMIT_CPU timer will expire before the
1481 * ITIMER_PROF timer, we have nothing else to do.
1482 */
1483 if (tsk->signal->rlim[RLIMIT_CPU].rlim_cur
1484 < cputime_to_secs(*newval))
1485 return;
1486 }
1487
1488 /*
1489 * Check whether there are any process timers already set to fire
1490 * before this one. If so, we don't have anything more to do.
1491 */
1492 head = &tsk->signal->cpu_timers[clock_idx];
1493 if (list_empty(head) ||
Pavel Emelianovb5e61812007-05-08 00:30:19 -07001494 cputime_ge(list_first_entry(head,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 struct cpu_timer_list, entry)->expires.cpu,
1496 *newval)) {
Frank Mayharf06febc2008-09-12 09:54:39 -07001497 switch (clock_idx) {
1498 case CPUCLOCK_PROF:
1499 tsk->signal->cputime_expires.prof_exp = *newval;
1500 break;
1501 case CPUCLOCK_VIRT:
1502 tsk->signal->cputime_expires.virt_exp = *newval;
1503 break;
1504 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505 }
1506}
1507
Toyo Abee4b76552006-09-29 02:00:29 -07001508static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
1509 struct timespec *rqtp, struct itimerspec *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 struct k_itimer timer;
1512 int error;
1513
1514 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 * Set up a temporary timer and then wait for it to go off.
1516 */
1517 memset(&timer, 0, sizeof timer);
1518 spin_lock_init(&timer.it_lock);
1519 timer.it_clock = which_clock;
1520 timer.it_overrun = -1;
1521 error = posix_cpu_timer_create(&timer);
1522 timer.it_process = current;
1523 if (!error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524 static struct itimerspec zero_it;
Toyo Abee4b76552006-09-29 02:00:29 -07001525
1526 memset(it, 0, sizeof *it);
1527 it->it_value = *rqtp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528
1529 spin_lock_irq(&timer.it_lock);
Toyo Abee4b76552006-09-29 02:00:29 -07001530 error = posix_cpu_timer_set(&timer, flags, it, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531 if (error) {
1532 spin_unlock_irq(&timer.it_lock);
1533 return error;
1534 }
1535
1536 while (!signal_pending(current)) {
1537 if (timer.it.cpu.expires.sched == 0) {
1538 /*
1539 * Our timer fired and was reset.
1540 */
1541 spin_unlock_irq(&timer.it_lock);
1542 return 0;
1543 }
1544
1545 /*
1546 * Block until cpu_timer_fire (or a signal) wakes us.
1547 */
1548 __set_current_state(TASK_INTERRUPTIBLE);
1549 spin_unlock_irq(&timer.it_lock);
1550 schedule();
1551 spin_lock_irq(&timer.it_lock);
1552 }
1553
1554 /*
1555 * We were interrupted by a signal.
1556 */
1557 sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
Toyo Abee4b76552006-09-29 02:00:29 -07001558 posix_cpu_timer_set(&timer, 0, &zero_it, it);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559 spin_unlock_irq(&timer.it_lock);
1560
Toyo Abee4b76552006-09-29 02:00:29 -07001561 if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 /*
1563 * It actually did fire already.
1564 */
1565 return 0;
1566 }
1567
Toyo Abee4b76552006-09-29 02:00:29 -07001568 error = -ERESTART_RESTARTBLOCK;
1569 }
1570
1571 return error;
1572}
1573
1574int posix_cpu_nsleep(const clockid_t which_clock, int flags,
1575 struct timespec *rqtp, struct timespec __user *rmtp)
1576{
1577 struct restart_block *restart_block =
1578 &current_thread_info()->restart_block;
1579 struct itimerspec it;
1580 int error;
1581
1582 /*
1583 * Diagnose required errors first.
1584 */
1585 if (CPUCLOCK_PERTHREAD(which_clock) &&
1586 (CPUCLOCK_PID(which_clock) == 0 ||
1587 CPUCLOCK_PID(which_clock) == current->pid))
1588 return -EINVAL;
1589
1590 error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
1591
1592 if (error == -ERESTART_RESTARTBLOCK) {
1593
1594 if (flags & TIMER_ABSTIME)
1595 return -ERESTARTNOHAND;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596 /*
Toyo Abee4b76552006-09-29 02:00:29 -07001597 * Report back to the user the time still remaining.
1598 */
1599 if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 return -EFAULT;
1601
Toyo Abe1711ef32006-09-29 02:00:28 -07001602 restart_block->fn = posix_cpu_nsleep_restart;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 restart_block->arg0 = which_clock;
Thomas Gleixner97735f22006-01-09 20:52:37 -08001604 restart_block->arg1 = (unsigned long) rmtp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001605 restart_block->arg2 = rqtp->tv_sec;
1606 restart_block->arg3 = rqtp->tv_nsec;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608 return error;
1609}
1610
Toyo Abe1711ef32006-09-29 02:00:28 -07001611long posix_cpu_nsleep_restart(struct restart_block *restart_block)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612{
1613 clockid_t which_clock = restart_block->arg0;
Thomas Gleixner97735f22006-01-09 20:52:37 -08001614 struct timespec __user *rmtp;
1615 struct timespec t;
Toyo Abee4b76552006-09-29 02:00:29 -07001616 struct itimerspec it;
1617 int error;
Thomas Gleixner97735f22006-01-09 20:52:37 -08001618
1619 rmtp = (struct timespec __user *) restart_block->arg1;
1620 t.tv_sec = restart_block->arg2;
1621 t.tv_nsec = restart_block->arg3;
1622
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 restart_block->fn = do_no_restart_syscall;
Toyo Abee4b76552006-09-29 02:00:29 -07001624 error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
1625
1626 if (error == -ERESTART_RESTARTBLOCK) {
1627 /*
1628 * Report back to the user the time still remaining.
1629 */
1630 if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1631 return -EFAULT;
1632
1633 restart_block->fn = posix_cpu_nsleep_restart;
1634 restart_block->arg0 = which_clock;
1635 restart_block->arg1 = (unsigned long) rmtp;
1636 restart_block->arg2 = t.tv_sec;
1637 restart_block->arg3 = t.tv_nsec;
1638 }
1639 return error;
1640
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641}
1642
1643
1644#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
1645#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
1646
Thomas Gleixnera924b042006-01-09 20:52:27 -08001647static int process_cpu_clock_getres(const clockid_t which_clock,
1648 struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649{
1650 return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
1651}
Thomas Gleixnera924b042006-01-09 20:52:27 -08001652static int process_cpu_clock_get(const clockid_t which_clock,
1653 struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654{
1655 return posix_cpu_clock_get(PROCESS_CLOCK, tp);
1656}
1657static int process_cpu_timer_create(struct k_itimer *timer)
1658{
1659 timer->it_clock = PROCESS_CLOCK;
1660 return posix_cpu_timer_create(timer);
1661}
Thomas Gleixnera924b042006-01-09 20:52:27 -08001662static int process_cpu_nsleep(const clockid_t which_clock, int flags,
Thomas Gleixner97735f22006-01-09 20:52:37 -08001663 struct timespec *rqtp,
1664 struct timespec __user *rmtp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665{
Thomas Gleixner97735f22006-01-09 20:52:37 -08001666 return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667}
Toyo Abe1711ef32006-09-29 02:00:28 -07001668static long process_cpu_nsleep_restart(struct restart_block *restart_block)
1669{
1670 return -EINVAL;
1671}
Thomas Gleixnera924b042006-01-09 20:52:27 -08001672static int thread_cpu_clock_getres(const clockid_t which_clock,
1673 struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674{
1675 return posix_cpu_clock_getres(THREAD_CLOCK, tp);
1676}
Thomas Gleixnera924b042006-01-09 20:52:27 -08001677static int thread_cpu_clock_get(const clockid_t which_clock,
1678 struct timespec *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679{
1680 return posix_cpu_clock_get(THREAD_CLOCK, tp);
1681}
1682static int thread_cpu_timer_create(struct k_itimer *timer)
1683{
1684 timer->it_clock = THREAD_CLOCK;
1685 return posix_cpu_timer_create(timer);
1686}
Thomas Gleixnera924b042006-01-09 20:52:27 -08001687static int thread_cpu_nsleep(const clockid_t which_clock, int flags,
Thomas Gleixner97735f22006-01-09 20:52:37 -08001688 struct timespec *rqtp, struct timespec __user *rmtp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689{
1690 return -EINVAL;
1691}
Toyo Abe1711ef32006-09-29 02:00:28 -07001692static long thread_cpu_nsleep_restart(struct restart_block *restart_block)
1693{
1694 return -EINVAL;
1695}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696
1697static __init int init_posix_cpu_timers(void)
1698{
1699 struct k_clock process = {
1700 .clock_getres = process_cpu_clock_getres,
1701 .clock_get = process_cpu_clock_get,
1702 .clock_set = do_posix_clock_nosettime,
1703 .timer_create = process_cpu_timer_create,
1704 .nsleep = process_cpu_nsleep,
Toyo Abe1711ef32006-09-29 02:00:28 -07001705 .nsleep_restart = process_cpu_nsleep_restart,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 };
1707 struct k_clock thread = {
1708 .clock_getres = thread_cpu_clock_getres,
1709 .clock_get = thread_cpu_clock_get,
1710 .clock_set = do_posix_clock_nosettime,
1711 .timer_create = thread_cpu_timer_create,
1712 .nsleep = thread_cpu_nsleep,
Toyo Abe1711ef32006-09-29 02:00:28 -07001713 .nsleep_restart = thread_cpu_nsleep_restart,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 };
Stanislaw Gruszka8356b5f2009-07-29 12:15:27 +02001715 struct timespec ts;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716
1717 register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
1718 register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
1719
Stanislaw Gruszkaa42548a2009-07-29 12:15:29 +02001720 cputime_to_timespec(cputime_one_jiffy, &ts);
Stanislaw Gruszka8356b5f2009-07-29 12:15:27 +02001721 onecputick = ts.tv_nsec;
1722 WARN_ON(ts.tv_sec != 0);
1723
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 return 0;
1725}
1726__initcall(init_posix_cpu_timers);