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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Implement CPU time clocks for the POSIX clock interface. | |
3 | */ | |
4 | ||
5 | #include <linux/sched.h> | |
6 | #include <linux/posix-timers.h> | |
1da177e4 | 7 | #include <linux/errno.h> |
f8bd2258 RZ |
8 | #include <linux/math64.h> |
9 | #include <asm/uaccess.h> | |
bb34d92f | 10 | #include <linux/kernel_stat.h> |
3f0a525e | 11 | #include <trace/events/timer.h> |
61337054 | 12 | #include <linux/random.h> |
a8572160 FW |
13 | #include <linux/tick.h> |
14 | #include <linux/workqueue.h> | |
1da177e4 | 15 | |
f06febc9 | 16 | /* |
f55db609 SG |
17 | * Called after updating RLIMIT_CPU to run cpu timer and update |
18 | * tsk->signal->cputime_expires expiration cache if necessary. Needs | |
19 | * siglock protection since other code may update expiration cache as | |
20 | * well. | |
f06febc9 | 21 | */ |
5ab46b34 | 22 | void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) |
f06febc9 | 23 | { |
42c4ab41 | 24 | cputime_t cputime = secs_to_cputime(rlim_new); |
f06febc9 | 25 | |
5ab46b34 JS |
26 | spin_lock_irq(&task->sighand->siglock); |
27 | set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL); | |
28 | spin_unlock_irq(&task->sighand->siglock); | |
f06febc9 FM |
29 | } |
30 | ||
a924b04d | 31 | static int check_clock(const clockid_t which_clock) |
1da177e4 LT |
32 | { |
33 | int error = 0; | |
34 | struct task_struct *p; | |
35 | const pid_t pid = CPUCLOCK_PID(which_clock); | |
36 | ||
37 | if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX) | |
38 | return -EINVAL; | |
39 | ||
40 | if (pid == 0) | |
41 | return 0; | |
42 | ||
c0deae8c | 43 | rcu_read_lock(); |
8dc86af0 | 44 | p = find_task_by_vpid(pid); |
bac0abd6 | 45 | if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? |
c0deae8c | 46 | same_thread_group(p, current) : has_group_leader_pid(p))) { |
1da177e4 LT |
47 | error = -EINVAL; |
48 | } | |
c0deae8c | 49 | rcu_read_unlock(); |
1da177e4 LT |
50 | |
51 | return error; | |
52 | } | |
53 | ||
55ccb616 | 54 | static inline unsigned long long |
a924b04d | 55 | timespec_to_sample(const clockid_t which_clock, const struct timespec *tp) |
1da177e4 | 56 | { |
55ccb616 FW |
57 | unsigned long long ret; |
58 | ||
59 | ret = 0; /* high half always zero when .cpu used */ | |
1da177e4 | 60 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
55ccb616 | 61 | ret = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; |
1da177e4 | 62 | } else { |
55ccb616 | 63 | ret = cputime_to_expires(timespec_to_cputime(tp)); |
1da177e4 LT |
64 | } |
65 | return ret; | |
66 | } | |
67 | ||
a924b04d | 68 | static void sample_to_timespec(const clockid_t which_clock, |
55ccb616 | 69 | unsigned long long expires, |
1da177e4 LT |
70 | struct timespec *tp) |
71 | { | |
f8bd2258 | 72 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) |
55ccb616 | 73 | *tp = ns_to_timespec(expires); |
f8bd2258 | 74 | else |
55ccb616 | 75 | cputime_to_timespec((__force cputime_t)expires, tp); |
1da177e4 LT |
76 | } |
77 | ||
78 | /* | |
79 | * Update expiry time from increment, and increase overrun count, | |
80 | * given the current clock sample. | |
81 | */ | |
7a4ed937 | 82 | static void bump_cpu_timer(struct k_itimer *timer, |
55ccb616 | 83 | unsigned long long now) |
1da177e4 LT |
84 | { |
85 | int i; | |
55ccb616 | 86 | unsigned long long delta, incr; |
1da177e4 | 87 | |
55ccb616 | 88 | if (timer->it.cpu.incr == 0) |
1da177e4 LT |
89 | return; |
90 | ||
55ccb616 FW |
91 | if (now < timer->it.cpu.expires) |
92 | return; | |
1da177e4 | 93 | |
55ccb616 FW |
94 | incr = timer->it.cpu.incr; |
95 | delta = now + incr - timer->it.cpu.expires; | |
1da177e4 | 96 | |
55ccb616 FW |
97 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
98 | for (i = 0; incr < delta - incr; i++) | |
99 | incr = incr << 1; | |
100 | ||
101 | for (; i >= 0; incr >>= 1, i--) { | |
102 | if (delta < incr) | |
103 | continue; | |
104 | ||
105 | timer->it.cpu.expires += incr; | |
106 | timer->it_overrun += 1 << i; | |
107 | delta -= incr; | |
1da177e4 LT |
108 | } |
109 | } | |
110 | ||
555347f6 FW |
111 | /** |
112 | * task_cputime_zero - Check a task_cputime struct for all zero fields. | |
113 | * | |
114 | * @cputime: The struct to compare. | |
115 | * | |
116 | * Checks @cputime to see if all fields are zero. Returns true if all fields | |
117 | * are zero, false if any field is nonzero. | |
118 | */ | |
119 | static inline int task_cputime_zero(const struct task_cputime *cputime) | |
120 | { | |
121 | if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) | |
122 | return 1; | |
123 | return 0; | |
124 | } | |
125 | ||
55ccb616 | 126 | static inline unsigned long long prof_ticks(struct task_struct *p) |
1da177e4 | 127 | { |
6fac4829 FW |
128 | cputime_t utime, stime; |
129 | ||
130 | task_cputime(p, &utime, &stime); | |
131 | ||
55ccb616 | 132 | return cputime_to_expires(utime + stime); |
1da177e4 | 133 | } |
55ccb616 | 134 | static inline unsigned long long virt_ticks(struct task_struct *p) |
1da177e4 | 135 | { |
6fac4829 FW |
136 | cputime_t utime; |
137 | ||
138 | task_cputime(p, &utime, NULL); | |
139 | ||
55ccb616 | 140 | return cputime_to_expires(utime); |
1da177e4 | 141 | } |
1da177e4 | 142 | |
bc2c8ea4 TG |
143 | static int |
144 | posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
1da177e4 LT |
145 | { |
146 | int error = check_clock(which_clock); | |
147 | if (!error) { | |
148 | tp->tv_sec = 0; | |
149 | tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ); | |
150 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { | |
151 | /* | |
152 | * If sched_clock is using a cycle counter, we | |
153 | * don't have any idea of its true resolution | |
154 | * exported, but it is much more than 1s/HZ. | |
155 | */ | |
156 | tp->tv_nsec = 1; | |
157 | } | |
158 | } | |
159 | return error; | |
160 | } | |
161 | ||
bc2c8ea4 TG |
162 | static int |
163 | posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) | |
1da177e4 LT |
164 | { |
165 | /* | |
166 | * You can never reset a CPU clock, but we check for other errors | |
167 | * in the call before failing with EPERM. | |
168 | */ | |
169 | int error = check_clock(which_clock); | |
170 | if (error == 0) { | |
171 | error = -EPERM; | |
172 | } | |
173 | return error; | |
174 | } | |
175 | ||
176 | ||
177 | /* | |
178 | * Sample a per-thread clock for the given task. | |
179 | */ | |
a924b04d | 180 | static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, |
55ccb616 | 181 | unsigned long long *sample) |
1da177e4 LT |
182 | { |
183 | switch (CPUCLOCK_WHICH(which_clock)) { | |
184 | default: | |
185 | return -EINVAL; | |
186 | case CPUCLOCK_PROF: | |
55ccb616 | 187 | *sample = prof_ticks(p); |
1da177e4 LT |
188 | break; |
189 | case CPUCLOCK_VIRT: | |
55ccb616 | 190 | *sample = virt_ticks(p); |
1da177e4 LT |
191 | break; |
192 | case CPUCLOCK_SCHED: | |
55ccb616 | 193 | *sample = task_sched_runtime(p); |
1da177e4 LT |
194 | break; |
195 | } | |
196 | return 0; | |
197 | } | |
198 | ||
1018016c JL |
199 | /* |
200 | * Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg | |
201 | * to avoid race conditions with concurrent updates to cputime. | |
202 | */ | |
203 | static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime) | |
4da94d49 | 204 | { |
1018016c JL |
205 | u64 curr_cputime; |
206 | retry: | |
207 | curr_cputime = atomic64_read(cputime); | |
208 | if (sum_cputime > curr_cputime) { | |
209 | if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime) | |
210 | goto retry; | |
211 | } | |
212 | } | |
4da94d49 | 213 | |
71107445 | 214 | static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum) |
1018016c | 215 | { |
71107445 JL |
216 | __update_gt_cputime(&cputime_atomic->utime, sum->utime); |
217 | __update_gt_cputime(&cputime_atomic->stime, sum->stime); | |
218 | __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime); | |
1018016c | 219 | } |
4da94d49 | 220 | |
71107445 JL |
221 | /* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */ |
222 | static inline void sample_cputime_atomic(struct task_cputime *times, | |
223 | struct task_cputime_atomic *atomic_times) | |
1018016c | 224 | { |
71107445 JL |
225 | times->utime = atomic64_read(&atomic_times->utime); |
226 | times->stime = atomic64_read(&atomic_times->stime); | |
227 | times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime); | |
4da94d49 PZ |
228 | } |
229 | ||
230 | void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) | |
231 | { | |
232 | struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; | |
233 | struct task_cputime sum; | |
4da94d49 | 234 | |
1018016c JL |
235 | /* Check if cputimer isn't running. This is accessed without locking. */ |
236 | if (!READ_ONCE(cputimer->running)) { | |
4da94d49 PZ |
237 | /* |
238 | * The POSIX timer interface allows for absolute time expiry | |
239 | * values through the TIMER_ABSTIME flag, therefore we have | |
1018016c | 240 | * to synchronize the timer to the clock every time we start it. |
4da94d49 PZ |
241 | */ |
242 | thread_group_cputime(tsk, &sum); | |
71107445 | 243 | update_gt_cputime(&cputimer->cputime_atomic, &sum); |
1018016c JL |
244 | |
245 | /* | |
246 | * We're setting cputimer->running without a lock. Ensure | |
247 | * this only gets written to in one operation. We set | |
248 | * running after update_gt_cputime() as a small optimization, | |
249 | * but barriers are not required because update_gt_cputime() | |
250 | * can handle concurrent updates. | |
251 | */ | |
252 | WRITE_ONCE(cputimer->running, 1); | |
253 | } | |
71107445 | 254 | sample_cputime_atomic(times, &cputimer->cputime_atomic); |
4da94d49 PZ |
255 | } |
256 | ||
1da177e4 LT |
257 | /* |
258 | * Sample a process (thread group) clock for the given group_leader task. | |
e73d84e3 FW |
259 | * Must be called with task sighand lock held for safe while_each_thread() |
260 | * traversal. | |
1da177e4 | 261 | */ |
bb34d92f FM |
262 | static int cpu_clock_sample_group(const clockid_t which_clock, |
263 | struct task_struct *p, | |
55ccb616 | 264 | unsigned long long *sample) |
1da177e4 | 265 | { |
f06febc9 FM |
266 | struct task_cputime cputime; |
267 | ||
eccdaeaf | 268 | switch (CPUCLOCK_WHICH(which_clock)) { |
1da177e4 LT |
269 | default: |
270 | return -EINVAL; | |
271 | case CPUCLOCK_PROF: | |
c5f8d995 | 272 | thread_group_cputime(p, &cputime); |
55ccb616 | 273 | *sample = cputime_to_expires(cputime.utime + cputime.stime); |
1da177e4 LT |
274 | break; |
275 | case CPUCLOCK_VIRT: | |
c5f8d995 | 276 | thread_group_cputime(p, &cputime); |
55ccb616 | 277 | *sample = cputime_to_expires(cputime.utime); |
1da177e4 LT |
278 | break; |
279 | case CPUCLOCK_SCHED: | |
d670ec13 | 280 | thread_group_cputime(p, &cputime); |
55ccb616 | 281 | *sample = cputime.sum_exec_runtime; |
1da177e4 LT |
282 | break; |
283 | } | |
284 | return 0; | |
285 | } | |
286 | ||
33ab0fec FW |
287 | static int posix_cpu_clock_get_task(struct task_struct *tsk, |
288 | const clockid_t which_clock, | |
289 | struct timespec *tp) | |
290 | { | |
291 | int err = -EINVAL; | |
292 | unsigned long long rtn; | |
293 | ||
294 | if (CPUCLOCK_PERTHREAD(which_clock)) { | |
295 | if (same_thread_group(tsk, current)) | |
296 | err = cpu_clock_sample(which_clock, tsk, &rtn); | |
297 | } else { | |
50875788 | 298 | if (tsk == current || thread_group_leader(tsk)) |
33ab0fec | 299 | err = cpu_clock_sample_group(which_clock, tsk, &rtn); |
33ab0fec FW |
300 | } |
301 | ||
302 | if (!err) | |
303 | sample_to_timespec(which_clock, rtn, tp); | |
304 | ||
305 | return err; | |
306 | } | |
307 | ||
1da177e4 | 308 | |
bc2c8ea4 | 309 | static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) |
1da177e4 LT |
310 | { |
311 | const pid_t pid = CPUCLOCK_PID(which_clock); | |
33ab0fec | 312 | int err = -EINVAL; |
1da177e4 LT |
313 | |
314 | if (pid == 0) { | |
315 | /* | |
316 | * Special case constant value for our own clocks. | |
317 | * We don't have to do any lookup to find ourselves. | |
318 | */ | |
33ab0fec | 319 | err = posix_cpu_clock_get_task(current, which_clock, tp); |
1da177e4 LT |
320 | } else { |
321 | /* | |
322 | * Find the given PID, and validate that the caller | |
323 | * should be able to see it. | |
324 | */ | |
325 | struct task_struct *p; | |
1f2ea083 | 326 | rcu_read_lock(); |
8dc86af0 | 327 | p = find_task_by_vpid(pid); |
33ab0fec FW |
328 | if (p) |
329 | err = posix_cpu_clock_get_task(p, which_clock, tp); | |
1f2ea083 | 330 | rcu_read_unlock(); |
1da177e4 LT |
331 | } |
332 | ||
33ab0fec | 333 | return err; |
1da177e4 LT |
334 | } |
335 | ||
336 | ||
337 | /* | |
338 | * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. | |
ba5ea951 SG |
339 | * This is called from sys_timer_create() and do_cpu_nanosleep() with the |
340 | * new timer already all-zeros initialized. | |
1da177e4 | 341 | */ |
bc2c8ea4 | 342 | static int posix_cpu_timer_create(struct k_itimer *new_timer) |
1da177e4 LT |
343 | { |
344 | int ret = 0; | |
345 | const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); | |
346 | struct task_struct *p; | |
347 | ||
348 | if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX) | |
349 | return -EINVAL; | |
350 | ||
351 | INIT_LIST_HEAD(&new_timer->it.cpu.entry); | |
1da177e4 | 352 | |
c0deae8c | 353 | rcu_read_lock(); |
1da177e4 LT |
354 | if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { |
355 | if (pid == 0) { | |
356 | p = current; | |
357 | } else { | |
8dc86af0 | 358 | p = find_task_by_vpid(pid); |
bac0abd6 | 359 | if (p && !same_thread_group(p, current)) |
1da177e4 LT |
360 | p = NULL; |
361 | } | |
362 | } else { | |
363 | if (pid == 0) { | |
364 | p = current->group_leader; | |
365 | } else { | |
8dc86af0 | 366 | p = find_task_by_vpid(pid); |
c0deae8c | 367 | if (p && !has_group_leader_pid(p)) |
1da177e4 LT |
368 | p = NULL; |
369 | } | |
370 | } | |
371 | new_timer->it.cpu.task = p; | |
372 | if (p) { | |
373 | get_task_struct(p); | |
374 | } else { | |
375 | ret = -EINVAL; | |
376 | } | |
c0deae8c | 377 | rcu_read_unlock(); |
1da177e4 LT |
378 | |
379 | return ret; | |
380 | } | |
381 | ||
382 | /* | |
383 | * Clean up a CPU-clock timer that is about to be destroyed. | |
384 | * This is called from timer deletion with the timer already locked. | |
385 | * If we return TIMER_RETRY, it's necessary to release the timer's lock | |
386 | * and try again. (This happens when the timer is in the middle of firing.) | |
387 | */ | |
bc2c8ea4 | 388 | static int posix_cpu_timer_del(struct k_itimer *timer) |
1da177e4 | 389 | { |
108150ea | 390 | int ret = 0; |
3d7a1427 FW |
391 | unsigned long flags; |
392 | struct sighand_struct *sighand; | |
393 | struct task_struct *p = timer->it.cpu.task; | |
1da177e4 | 394 | |
a3222f88 | 395 | WARN_ON_ONCE(p == NULL); |
108150ea | 396 | |
3d7a1427 FW |
397 | /* |
398 | * Protect against sighand release/switch in exit/exec and process/ | |
399 | * thread timer list entry concurrent read/writes. | |
400 | */ | |
401 | sighand = lock_task_sighand(p, &flags); | |
402 | if (unlikely(sighand == NULL)) { | |
a3222f88 FW |
403 | /* |
404 | * We raced with the reaping of the task. | |
405 | * The deletion should have cleared us off the list. | |
406 | */ | |
531f64fd | 407 | WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry)); |
a3222f88 | 408 | } else { |
a3222f88 FW |
409 | if (timer->it.cpu.firing) |
410 | ret = TIMER_RETRY; | |
411 | else | |
412 | list_del(&timer->it.cpu.entry); | |
3d7a1427 FW |
413 | |
414 | unlock_task_sighand(p, &flags); | |
1da177e4 | 415 | } |
a3222f88 FW |
416 | |
417 | if (!ret) | |
418 | put_task_struct(p); | |
1da177e4 | 419 | |
108150ea | 420 | return ret; |
1da177e4 LT |
421 | } |
422 | ||
af82eb3c | 423 | static void cleanup_timers_list(struct list_head *head) |
1a7fa510 FW |
424 | { |
425 | struct cpu_timer_list *timer, *next; | |
426 | ||
a0b2062b | 427 | list_for_each_entry_safe(timer, next, head, entry) |
1a7fa510 | 428 | list_del_init(&timer->entry); |
1a7fa510 FW |
429 | } |
430 | ||
1da177e4 LT |
431 | /* |
432 | * Clean out CPU timers still ticking when a thread exited. The task | |
433 | * pointer is cleared, and the expiry time is replaced with the residual | |
434 | * time for later timer_gettime calls to return. | |
435 | * This must be called with the siglock held. | |
436 | */ | |
af82eb3c | 437 | static void cleanup_timers(struct list_head *head) |
1da177e4 | 438 | { |
af82eb3c FW |
439 | cleanup_timers_list(head); |
440 | cleanup_timers_list(++head); | |
441 | cleanup_timers_list(++head); | |
1da177e4 LT |
442 | } |
443 | ||
444 | /* | |
445 | * These are both called with the siglock held, when the current thread | |
446 | * is being reaped. When the final (leader) thread in the group is reaped, | |
447 | * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit. | |
448 | */ | |
449 | void posix_cpu_timers_exit(struct task_struct *tsk) | |
450 | { | |
61337054 NK |
451 | add_device_randomness((const void*) &tsk->se.sum_exec_runtime, |
452 | sizeof(unsigned long long)); | |
af82eb3c | 453 | cleanup_timers(tsk->cpu_timers); |
1da177e4 LT |
454 | |
455 | } | |
456 | void posix_cpu_timers_exit_group(struct task_struct *tsk) | |
457 | { | |
af82eb3c | 458 | cleanup_timers(tsk->signal->cpu_timers); |
1da177e4 LT |
459 | } |
460 | ||
d1e3b6d1 SG |
461 | static inline int expires_gt(cputime_t expires, cputime_t new_exp) |
462 | { | |
64861634 | 463 | return expires == 0 || expires > new_exp; |
d1e3b6d1 SG |
464 | } |
465 | ||
1da177e4 LT |
466 | /* |
467 | * Insert the timer on the appropriate list before any timers that | |
e73d84e3 | 468 | * expire later. This must be called with the sighand lock held. |
1da177e4 | 469 | */ |
5eb9aa64 | 470 | static void arm_timer(struct k_itimer *timer) |
1da177e4 LT |
471 | { |
472 | struct task_struct *p = timer->it.cpu.task; | |
473 | struct list_head *head, *listpos; | |
5eb9aa64 | 474 | struct task_cputime *cputime_expires; |
1da177e4 LT |
475 | struct cpu_timer_list *const nt = &timer->it.cpu; |
476 | struct cpu_timer_list *next; | |
1da177e4 | 477 | |
5eb9aa64 SG |
478 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
479 | head = p->cpu_timers; | |
480 | cputime_expires = &p->cputime_expires; | |
481 | } else { | |
482 | head = p->signal->cpu_timers; | |
483 | cputime_expires = &p->signal->cputime_expires; | |
484 | } | |
1da177e4 LT |
485 | head += CPUCLOCK_WHICH(timer->it_clock); |
486 | ||
1da177e4 | 487 | listpos = head; |
5eb9aa64 | 488 | list_for_each_entry(next, head, entry) { |
55ccb616 | 489 | if (nt->expires < next->expires) |
5eb9aa64 SG |
490 | break; |
491 | listpos = &next->entry; | |
1da177e4 LT |
492 | } |
493 | list_add(&nt->entry, listpos); | |
494 | ||
495 | if (listpos == head) { | |
55ccb616 | 496 | unsigned long long exp = nt->expires; |
5eb9aa64 | 497 | |
1da177e4 | 498 | /* |
5eb9aa64 SG |
499 | * We are the new earliest-expiring POSIX 1.b timer, hence |
500 | * need to update expiration cache. Take into account that | |
501 | * for process timers we share expiration cache with itimers | |
502 | * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME. | |
1da177e4 LT |
503 | */ |
504 | ||
5eb9aa64 SG |
505 | switch (CPUCLOCK_WHICH(timer->it_clock)) { |
506 | case CPUCLOCK_PROF: | |
55ccb616 FW |
507 | if (expires_gt(cputime_expires->prof_exp, expires_to_cputime(exp))) |
508 | cputime_expires->prof_exp = expires_to_cputime(exp); | |
5eb9aa64 SG |
509 | break; |
510 | case CPUCLOCK_VIRT: | |
55ccb616 FW |
511 | if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp))) |
512 | cputime_expires->virt_exp = expires_to_cputime(exp); | |
5eb9aa64 SG |
513 | break; |
514 | case CPUCLOCK_SCHED: | |
515 | if (cputime_expires->sched_exp == 0 || | |
55ccb616 FW |
516 | cputime_expires->sched_exp > exp) |
517 | cputime_expires->sched_exp = exp; | |
5eb9aa64 | 518 | break; |
1da177e4 LT |
519 | } |
520 | } | |
1da177e4 LT |
521 | } |
522 | ||
523 | /* | |
524 | * The timer is locked, fire it and arrange for its reload. | |
525 | */ | |
526 | static void cpu_timer_fire(struct k_itimer *timer) | |
527 | { | |
1f169f84 SG |
528 | if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { |
529 | /* | |
530 | * User don't want any signal. | |
531 | */ | |
55ccb616 | 532 | timer->it.cpu.expires = 0; |
1f169f84 | 533 | } else if (unlikely(timer->sigq == NULL)) { |
1da177e4 LT |
534 | /* |
535 | * This a special case for clock_nanosleep, | |
536 | * not a normal timer from sys_timer_create. | |
537 | */ | |
538 | wake_up_process(timer->it_process); | |
55ccb616 FW |
539 | timer->it.cpu.expires = 0; |
540 | } else if (timer->it.cpu.incr == 0) { | |
1da177e4 LT |
541 | /* |
542 | * One-shot timer. Clear it as soon as it's fired. | |
543 | */ | |
544 | posix_timer_event(timer, 0); | |
55ccb616 | 545 | timer->it.cpu.expires = 0; |
1da177e4 LT |
546 | } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { |
547 | /* | |
548 | * The signal did not get queued because the signal | |
549 | * was ignored, so we won't get any callback to | |
550 | * reload the timer. But we need to keep it | |
551 | * ticking in case the signal is deliverable next time. | |
552 | */ | |
553 | posix_cpu_timer_schedule(timer); | |
554 | } | |
555 | } | |
556 | ||
3997ad31 PZ |
557 | /* |
558 | * Sample a process (thread group) timer for the given group_leader task. | |
e73d84e3 FW |
559 | * Must be called with task sighand lock held for safe while_each_thread() |
560 | * traversal. | |
3997ad31 PZ |
561 | */ |
562 | static int cpu_timer_sample_group(const clockid_t which_clock, | |
563 | struct task_struct *p, | |
55ccb616 | 564 | unsigned long long *sample) |
3997ad31 PZ |
565 | { |
566 | struct task_cputime cputime; | |
567 | ||
568 | thread_group_cputimer(p, &cputime); | |
569 | switch (CPUCLOCK_WHICH(which_clock)) { | |
570 | default: | |
571 | return -EINVAL; | |
572 | case CPUCLOCK_PROF: | |
55ccb616 | 573 | *sample = cputime_to_expires(cputime.utime + cputime.stime); |
3997ad31 PZ |
574 | break; |
575 | case CPUCLOCK_VIRT: | |
55ccb616 | 576 | *sample = cputime_to_expires(cputime.utime); |
3997ad31 PZ |
577 | break; |
578 | case CPUCLOCK_SCHED: | |
23cfa361 | 579 | *sample = cputime.sum_exec_runtime; |
3997ad31 PZ |
580 | break; |
581 | } | |
582 | return 0; | |
583 | } | |
584 | ||
a8572160 FW |
585 | #ifdef CONFIG_NO_HZ_FULL |
586 | static void nohz_kick_work_fn(struct work_struct *work) | |
587 | { | |
588 | tick_nohz_full_kick_all(); | |
589 | } | |
590 | ||
591 | static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn); | |
592 | ||
593 | /* | |
594 | * We need the IPIs to be sent from sane process context. | |
595 | * The posix cpu timers are always set with irqs disabled. | |
596 | */ | |
597 | static void posix_cpu_timer_kick_nohz(void) | |
598 | { | |
d4283c65 FW |
599 | if (context_tracking_is_enabled()) |
600 | schedule_work(&nohz_kick_work); | |
a8572160 | 601 | } |
555347f6 FW |
602 | |
603 | bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk) | |
604 | { | |
605 | if (!task_cputime_zero(&tsk->cputime_expires)) | |
6ac29178 | 606 | return false; |
555347f6 | 607 | |
1018016c JL |
608 | /* Check if cputimer is running. This is accessed without locking. */ |
609 | if (READ_ONCE(tsk->signal->cputimer.running)) | |
6ac29178 | 610 | return false; |
555347f6 | 611 | |
6ac29178 | 612 | return true; |
555347f6 | 613 | } |
a8572160 FW |
614 | #else |
615 | static inline void posix_cpu_timer_kick_nohz(void) { } | |
616 | #endif | |
617 | ||
1da177e4 LT |
618 | /* |
619 | * Guts of sys_timer_settime for CPU timers. | |
620 | * This is called with the timer locked and interrupts disabled. | |
621 | * If we return TIMER_RETRY, it's necessary to release the timer's lock | |
622 | * and try again. (This happens when the timer is in the middle of firing.) | |
623 | */ | |
e73d84e3 | 624 | static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, |
bc2c8ea4 | 625 | struct itimerspec *new, struct itimerspec *old) |
1da177e4 | 626 | { |
e73d84e3 FW |
627 | unsigned long flags; |
628 | struct sighand_struct *sighand; | |
1da177e4 | 629 | struct task_struct *p = timer->it.cpu.task; |
55ccb616 | 630 | unsigned long long old_expires, new_expires, old_incr, val; |
1da177e4 LT |
631 | int ret; |
632 | ||
a3222f88 | 633 | WARN_ON_ONCE(p == NULL); |
1da177e4 LT |
634 | |
635 | new_expires = timespec_to_sample(timer->it_clock, &new->it_value); | |
636 | ||
1da177e4 | 637 | /* |
e73d84e3 FW |
638 | * Protect against sighand release/switch in exit/exec and p->cpu_timers |
639 | * and p->signal->cpu_timers read/write in arm_timer() | |
640 | */ | |
641 | sighand = lock_task_sighand(p, &flags); | |
642 | /* | |
643 | * If p has just been reaped, we can no | |
1da177e4 LT |
644 | * longer get any information about it at all. |
645 | */ | |
e73d84e3 | 646 | if (unlikely(sighand == NULL)) { |
1da177e4 LT |
647 | return -ESRCH; |
648 | } | |
649 | ||
650 | /* | |
651 | * Disarm any old timer after extracting its expiry time. | |
652 | */ | |
531f64fd | 653 | WARN_ON_ONCE(!irqs_disabled()); |
a69ac4a7 ON |
654 | |
655 | ret = 0; | |
ae1a78ee | 656 | old_incr = timer->it.cpu.incr; |
1da177e4 | 657 | old_expires = timer->it.cpu.expires; |
a69ac4a7 ON |
658 | if (unlikely(timer->it.cpu.firing)) { |
659 | timer->it.cpu.firing = -1; | |
660 | ret = TIMER_RETRY; | |
661 | } else | |
662 | list_del_init(&timer->it.cpu.entry); | |
1da177e4 LT |
663 | |
664 | /* | |
665 | * We need to sample the current value to convert the new | |
666 | * value from to relative and absolute, and to convert the | |
667 | * old value from absolute to relative. To set a process | |
668 | * timer, we need a sample to balance the thread expiry | |
669 | * times (in arm_timer). With an absolute time, we must | |
670 | * check if it's already passed. In short, we need a sample. | |
671 | */ | |
672 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
673 | cpu_clock_sample(timer->it_clock, p, &val); | |
674 | } else { | |
3997ad31 | 675 | cpu_timer_sample_group(timer->it_clock, p, &val); |
1da177e4 LT |
676 | } |
677 | ||
678 | if (old) { | |
55ccb616 | 679 | if (old_expires == 0) { |
1da177e4 LT |
680 | old->it_value.tv_sec = 0; |
681 | old->it_value.tv_nsec = 0; | |
682 | } else { | |
683 | /* | |
684 | * Update the timer in case it has | |
685 | * overrun already. If it has, | |
686 | * we'll report it as having overrun | |
687 | * and with the next reloaded timer | |
688 | * already ticking, though we are | |
689 | * swallowing that pending | |
690 | * notification here to install the | |
691 | * new setting. | |
692 | */ | |
693 | bump_cpu_timer(timer, val); | |
55ccb616 FW |
694 | if (val < timer->it.cpu.expires) { |
695 | old_expires = timer->it.cpu.expires - val; | |
1da177e4 LT |
696 | sample_to_timespec(timer->it_clock, |
697 | old_expires, | |
698 | &old->it_value); | |
699 | } else { | |
700 | old->it_value.tv_nsec = 1; | |
701 | old->it_value.tv_sec = 0; | |
702 | } | |
703 | } | |
704 | } | |
705 | ||
a69ac4a7 | 706 | if (unlikely(ret)) { |
1da177e4 LT |
707 | /* |
708 | * We are colliding with the timer actually firing. | |
709 | * Punt after filling in the timer's old value, and | |
710 | * disable this firing since we are already reporting | |
711 | * it as an overrun (thanks to bump_cpu_timer above). | |
712 | */ | |
e73d84e3 | 713 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
714 | goto out; |
715 | } | |
716 | ||
e73d84e3 | 717 | if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) { |
55ccb616 | 718 | new_expires += val; |
1da177e4 LT |
719 | } |
720 | ||
721 | /* | |
722 | * Install the new expiry time (or zero). | |
723 | * For a timer with no notification action, we don't actually | |
724 | * arm the timer (we'll just fake it for timer_gettime). | |
725 | */ | |
726 | timer->it.cpu.expires = new_expires; | |
55ccb616 | 727 | if (new_expires != 0 && val < new_expires) { |
5eb9aa64 | 728 | arm_timer(timer); |
1da177e4 LT |
729 | } |
730 | ||
e73d84e3 | 731 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
732 | /* |
733 | * Install the new reload setting, and | |
734 | * set up the signal and overrun bookkeeping. | |
735 | */ | |
736 | timer->it.cpu.incr = timespec_to_sample(timer->it_clock, | |
737 | &new->it_interval); | |
738 | ||
739 | /* | |
740 | * This acts as a modification timestamp for the timer, | |
741 | * so any automatic reload attempt will punt on seeing | |
742 | * that we have reset the timer manually. | |
743 | */ | |
744 | timer->it_requeue_pending = (timer->it_requeue_pending + 2) & | |
745 | ~REQUEUE_PENDING; | |
746 | timer->it_overrun_last = 0; | |
747 | timer->it_overrun = -1; | |
748 | ||
55ccb616 | 749 | if (new_expires != 0 && !(val < new_expires)) { |
1da177e4 LT |
750 | /* |
751 | * The designated time already passed, so we notify | |
752 | * immediately, even if the thread never runs to | |
753 | * accumulate more time on this clock. | |
754 | */ | |
755 | cpu_timer_fire(timer); | |
756 | } | |
757 | ||
758 | ret = 0; | |
759 | out: | |
760 | if (old) { | |
761 | sample_to_timespec(timer->it_clock, | |
ae1a78ee | 762 | old_incr, &old->it_interval); |
1da177e4 | 763 | } |
a8572160 FW |
764 | if (!ret) |
765 | posix_cpu_timer_kick_nohz(); | |
1da177e4 LT |
766 | return ret; |
767 | } | |
768 | ||
bc2c8ea4 | 769 | static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) |
1da177e4 | 770 | { |
55ccb616 | 771 | unsigned long long now; |
1da177e4 | 772 | struct task_struct *p = timer->it.cpu.task; |
1da177e4 | 773 | |
a3222f88 FW |
774 | WARN_ON_ONCE(p == NULL); |
775 | ||
1da177e4 LT |
776 | /* |
777 | * Easy part: convert the reload time. | |
778 | */ | |
779 | sample_to_timespec(timer->it_clock, | |
780 | timer->it.cpu.incr, &itp->it_interval); | |
781 | ||
55ccb616 | 782 | if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */ |
1da177e4 LT |
783 | itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; |
784 | return; | |
785 | } | |
786 | ||
1da177e4 LT |
787 | /* |
788 | * Sample the clock to take the difference with the expiry time. | |
789 | */ | |
790 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
791 | cpu_clock_sample(timer->it_clock, p, &now); | |
1da177e4 | 792 | } else { |
e73d84e3 FW |
793 | struct sighand_struct *sighand; |
794 | unsigned long flags; | |
795 | ||
796 | /* | |
797 | * Protect against sighand release/switch in exit/exec and | |
798 | * also make timer sampling safe if it ends up calling | |
799 | * thread_group_cputime(). | |
800 | */ | |
801 | sighand = lock_task_sighand(p, &flags); | |
802 | if (unlikely(sighand == NULL)) { | |
1da177e4 LT |
803 | /* |
804 | * The process has been reaped. | |
805 | * We can't even collect a sample any more. | |
806 | * Call the timer disarmed, nothing else to do. | |
807 | */ | |
55ccb616 | 808 | timer->it.cpu.expires = 0; |
a3222f88 FW |
809 | sample_to_timespec(timer->it_clock, timer->it.cpu.expires, |
810 | &itp->it_value); | |
1da177e4 | 811 | } else { |
3997ad31 | 812 | cpu_timer_sample_group(timer->it_clock, p, &now); |
e73d84e3 | 813 | unlock_task_sighand(p, &flags); |
1da177e4 | 814 | } |
1da177e4 LT |
815 | } |
816 | ||
55ccb616 | 817 | if (now < timer->it.cpu.expires) { |
1da177e4 | 818 | sample_to_timespec(timer->it_clock, |
55ccb616 | 819 | timer->it.cpu.expires - now, |
1da177e4 LT |
820 | &itp->it_value); |
821 | } else { | |
822 | /* | |
823 | * The timer should have expired already, but the firing | |
824 | * hasn't taken place yet. Say it's just about to expire. | |
825 | */ | |
826 | itp->it_value.tv_nsec = 1; | |
827 | itp->it_value.tv_sec = 0; | |
828 | } | |
829 | } | |
830 | ||
2473f3e7 FW |
831 | static unsigned long long |
832 | check_timers_list(struct list_head *timers, | |
833 | struct list_head *firing, | |
834 | unsigned long long curr) | |
835 | { | |
836 | int maxfire = 20; | |
837 | ||
838 | while (!list_empty(timers)) { | |
839 | struct cpu_timer_list *t; | |
840 | ||
841 | t = list_first_entry(timers, struct cpu_timer_list, entry); | |
842 | ||
843 | if (!--maxfire || curr < t->expires) | |
844 | return t->expires; | |
845 | ||
846 | t->firing = 1; | |
847 | list_move_tail(&t->entry, firing); | |
848 | } | |
849 | ||
850 | return 0; | |
851 | } | |
852 | ||
1da177e4 LT |
853 | /* |
854 | * Check for any per-thread CPU timers that have fired and move them off | |
855 | * the tsk->cpu_timers[N] list onto the firing list. Here we update the | |
856 | * tsk->it_*_expires values to reflect the remaining thread CPU timers. | |
857 | */ | |
858 | static void check_thread_timers(struct task_struct *tsk, | |
859 | struct list_head *firing) | |
860 | { | |
861 | struct list_head *timers = tsk->cpu_timers; | |
78f2c7db | 862 | struct signal_struct *const sig = tsk->signal; |
2473f3e7 FW |
863 | struct task_cputime *tsk_expires = &tsk->cputime_expires; |
864 | unsigned long long expires; | |
d4bb5274 | 865 | unsigned long soft; |
1da177e4 | 866 | |
2473f3e7 FW |
867 | expires = check_timers_list(timers, firing, prof_ticks(tsk)); |
868 | tsk_expires->prof_exp = expires_to_cputime(expires); | |
1da177e4 | 869 | |
2473f3e7 FW |
870 | expires = check_timers_list(++timers, firing, virt_ticks(tsk)); |
871 | tsk_expires->virt_exp = expires_to_cputime(expires); | |
1da177e4 | 872 | |
2473f3e7 FW |
873 | tsk_expires->sched_exp = check_timers_list(++timers, firing, |
874 | tsk->se.sum_exec_runtime); | |
78f2c7db PZ |
875 | |
876 | /* | |
877 | * Check for the special case thread timers. | |
878 | */ | |
316c1608 | 879 | soft = READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur); |
d4bb5274 | 880 | if (soft != RLIM_INFINITY) { |
78d7d407 | 881 | unsigned long hard = |
316c1608 | 882 | READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max); |
78f2c7db | 883 | |
5a52dd50 PZ |
884 | if (hard != RLIM_INFINITY && |
885 | tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { | |
78f2c7db PZ |
886 | /* |
887 | * At the hard limit, we just die. | |
888 | * No need to calculate anything else now. | |
889 | */ | |
890 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); | |
891 | return; | |
892 | } | |
d4bb5274 | 893 | if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) { |
78f2c7db PZ |
894 | /* |
895 | * At the soft limit, send a SIGXCPU every second. | |
896 | */ | |
d4bb5274 JS |
897 | if (soft < hard) { |
898 | soft += USEC_PER_SEC; | |
899 | sig->rlim[RLIMIT_RTTIME].rlim_cur = soft; | |
78f2c7db | 900 | } |
81d50bb2 HS |
901 | printk(KERN_INFO |
902 | "RT Watchdog Timeout: %s[%d]\n", | |
903 | tsk->comm, task_pid_nr(tsk)); | |
78f2c7db PZ |
904 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
905 | } | |
906 | } | |
1da177e4 LT |
907 | } |
908 | ||
1018016c | 909 | static inline void stop_process_timers(struct signal_struct *sig) |
3fccfd67 | 910 | { |
15365c10 | 911 | struct thread_group_cputimer *cputimer = &sig->cputimer; |
3fccfd67 | 912 | |
1018016c JL |
913 | /* Turn off cputimer->running. This is done without locking. */ |
914 | WRITE_ONCE(cputimer->running, 0); | |
3fccfd67 PZ |
915 | } |
916 | ||
8356b5f9 SG |
917 | static u32 onecputick; |
918 | ||
42c4ab41 | 919 | static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, |
55ccb616 FW |
920 | unsigned long long *expires, |
921 | unsigned long long cur_time, int signo) | |
42c4ab41 | 922 | { |
64861634 | 923 | if (!it->expires) |
42c4ab41 SG |
924 | return; |
925 | ||
64861634 MS |
926 | if (cur_time >= it->expires) { |
927 | if (it->incr) { | |
928 | it->expires += it->incr; | |
8356b5f9 SG |
929 | it->error += it->incr_error; |
930 | if (it->error >= onecputick) { | |
64861634 | 931 | it->expires -= cputime_one_jiffy; |
8356b5f9 SG |
932 | it->error -= onecputick; |
933 | } | |
3f0a525e | 934 | } else { |
64861634 | 935 | it->expires = 0; |
3f0a525e | 936 | } |
42c4ab41 | 937 | |
3f0a525e XG |
938 | trace_itimer_expire(signo == SIGPROF ? |
939 | ITIMER_PROF : ITIMER_VIRTUAL, | |
940 | tsk->signal->leader_pid, cur_time); | |
42c4ab41 SG |
941 | __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); |
942 | } | |
943 | ||
64861634 | 944 | if (it->expires && (!*expires || it->expires < *expires)) { |
42c4ab41 SG |
945 | *expires = it->expires; |
946 | } | |
947 | } | |
948 | ||
1da177e4 LT |
949 | /* |
950 | * Check for any per-thread CPU timers that have fired and move them | |
951 | * off the tsk->*_timers list onto the firing list. Per-thread timers | |
952 | * have already been taken off. | |
953 | */ | |
954 | static void check_process_timers(struct task_struct *tsk, | |
955 | struct list_head *firing) | |
956 | { | |
957 | struct signal_struct *const sig = tsk->signal; | |
55ccb616 | 958 | unsigned long long utime, ptime, virt_expires, prof_expires; |
41b86e9c | 959 | unsigned long long sum_sched_runtime, sched_expires; |
1da177e4 | 960 | struct list_head *timers = sig->cpu_timers; |
f06febc9 | 961 | struct task_cputime cputime; |
d4bb5274 | 962 | unsigned long soft; |
1da177e4 | 963 | |
1da177e4 LT |
964 | /* |
965 | * Collect the current process totals. | |
966 | */ | |
4cd4c1b4 | 967 | thread_group_cputimer(tsk, &cputime); |
55ccb616 FW |
968 | utime = cputime_to_expires(cputime.utime); |
969 | ptime = utime + cputime_to_expires(cputime.stime); | |
f06febc9 | 970 | sum_sched_runtime = cputime.sum_exec_runtime; |
1da177e4 | 971 | |
2473f3e7 FW |
972 | prof_expires = check_timers_list(timers, firing, ptime); |
973 | virt_expires = check_timers_list(++timers, firing, utime); | |
974 | sched_expires = check_timers_list(++timers, firing, sum_sched_runtime); | |
1da177e4 LT |
975 | |
976 | /* | |
977 | * Check for the special case process timers. | |
978 | */ | |
42c4ab41 SG |
979 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime, |
980 | SIGPROF); | |
981 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime, | |
982 | SIGVTALRM); | |
316c1608 | 983 | soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur); |
d4bb5274 | 984 | if (soft != RLIM_INFINITY) { |
1da177e4 | 985 | unsigned long psecs = cputime_to_secs(ptime); |
78d7d407 | 986 | unsigned long hard = |
316c1608 | 987 | READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_max); |
1da177e4 | 988 | cputime_t x; |
d4bb5274 | 989 | if (psecs >= hard) { |
1da177e4 LT |
990 | /* |
991 | * At the hard limit, we just die. | |
992 | * No need to calculate anything else now. | |
993 | */ | |
994 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); | |
995 | return; | |
996 | } | |
d4bb5274 | 997 | if (psecs >= soft) { |
1da177e4 LT |
998 | /* |
999 | * At the soft limit, send a SIGXCPU every second. | |
1000 | */ | |
1001 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); | |
d4bb5274 JS |
1002 | if (soft < hard) { |
1003 | soft++; | |
1004 | sig->rlim[RLIMIT_CPU].rlim_cur = soft; | |
1da177e4 LT |
1005 | } |
1006 | } | |
d4bb5274 | 1007 | x = secs_to_cputime(soft); |
64861634 | 1008 | if (!prof_expires || x < prof_expires) { |
1da177e4 LT |
1009 | prof_expires = x; |
1010 | } | |
1011 | } | |
1012 | ||
55ccb616 FW |
1013 | sig->cputime_expires.prof_exp = expires_to_cputime(prof_expires); |
1014 | sig->cputime_expires.virt_exp = expires_to_cputime(virt_expires); | |
29f87b79 SG |
1015 | sig->cputime_expires.sched_exp = sched_expires; |
1016 | if (task_cputime_zero(&sig->cputime_expires)) | |
1017 | stop_process_timers(sig); | |
1da177e4 LT |
1018 | } |
1019 | ||
1020 | /* | |
1021 | * This is called from the signal code (via do_schedule_next_timer) | |
1022 | * when the last timer signal was delivered and we have to reload the timer. | |
1023 | */ | |
1024 | void posix_cpu_timer_schedule(struct k_itimer *timer) | |
1025 | { | |
e73d84e3 FW |
1026 | struct sighand_struct *sighand; |
1027 | unsigned long flags; | |
1da177e4 | 1028 | struct task_struct *p = timer->it.cpu.task; |
55ccb616 | 1029 | unsigned long long now; |
1da177e4 | 1030 | |
a3222f88 | 1031 | WARN_ON_ONCE(p == NULL); |
1da177e4 LT |
1032 | |
1033 | /* | |
1034 | * Fetch the current sample and update the timer's expiry time. | |
1035 | */ | |
1036 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
1037 | cpu_clock_sample(timer->it_clock, p, &now); | |
1038 | bump_cpu_timer(timer, now); | |
724a3713 | 1039 | if (unlikely(p->exit_state)) |
708f430d | 1040 | goto out; |
724a3713 | 1041 | |
e73d84e3 FW |
1042 | /* Protect timer list r/w in arm_timer() */ |
1043 | sighand = lock_task_sighand(p, &flags); | |
1044 | if (!sighand) | |
1045 | goto out; | |
1da177e4 | 1046 | } else { |
e73d84e3 FW |
1047 | /* |
1048 | * Protect arm_timer() and timer sampling in case of call to | |
1049 | * thread_group_cputime(). | |
1050 | */ | |
1051 | sighand = lock_task_sighand(p, &flags); | |
1052 | if (unlikely(sighand == NULL)) { | |
1da177e4 LT |
1053 | /* |
1054 | * The process has been reaped. | |
1055 | * We can't even collect a sample any more. | |
1056 | */ | |
55ccb616 | 1057 | timer->it.cpu.expires = 0; |
c925077c | 1058 | goto out; |
1da177e4 | 1059 | } else if (unlikely(p->exit_state) && thread_group_empty(p)) { |
e73d84e3 | 1060 | unlock_task_sighand(p, &flags); |
d430b917 | 1061 | /* Optimizations: if the process is dying, no need to rearm */ |
c925077c | 1062 | goto out; |
1da177e4 | 1063 | } |
3997ad31 | 1064 | cpu_timer_sample_group(timer->it_clock, p, &now); |
1da177e4 | 1065 | bump_cpu_timer(timer, now); |
e73d84e3 | 1066 | /* Leave the sighand locked for the call below. */ |
1da177e4 LT |
1067 | } |
1068 | ||
1069 | /* | |
1070 | * Now re-arm for the new expiry time. | |
1071 | */ | |
531f64fd | 1072 | WARN_ON_ONCE(!irqs_disabled()); |
5eb9aa64 | 1073 | arm_timer(timer); |
e73d84e3 | 1074 | unlock_task_sighand(p, &flags); |
708f430d | 1075 | |
c925077c FW |
1076 | /* Kick full dynticks CPUs in case they need to tick on the new timer */ |
1077 | posix_cpu_timer_kick_nohz(); | |
708f430d RM |
1078 | out: |
1079 | timer->it_overrun_last = timer->it_overrun; | |
1080 | timer->it_overrun = -1; | |
1081 | ++timer->it_requeue_pending; | |
1da177e4 LT |
1082 | } |
1083 | ||
f06febc9 FM |
1084 | /** |
1085 | * task_cputime_expired - Compare two task_cputime entities. | |
1086 | * | |
1087 | * @sample: The task_cputime structure to be checked for expiration. | |
1088 | * @expires: Expiration times, against which @sample will be checked. | |
1089 | * | |
1090 | * Checks @sample against @expires to see if any field of @sample has expired. | |
1091 | * Returns true if any field of the former is greater than the corresponding | |
1092 | * field of the latter if the latter field is set. Otherwise returns false. | |
1093 | */ | |
1094 | static inline int task_cputime_expired(const struct task_cputime *sample, | |
1095 | const struct task_cputime *expires) | |
1096 | { | |
64861634 | 1097 | if (expires->utime && sample->utime >= expires->utime) |
f06febc9 | 1098 | return 1; |
64861634 | 1099 | if (expires->stime && sample->utime + sample->stime >= expires->stime) |
f06febc9 FM |
1100 | return 1; |
1101 | if (expires->sum_exec_runtime != 0 && | |
1102 | sample->sum_exec_runtime >= expires->sum_exec_runtime) | |
1103 | return 1; | |
1104 | return 0; | |
1105 | } | |
1106 | ||
1107 | /** | |
1108 | * fastpath_timer_check - POSIX CPU timers fast path. | |
1109 | * | |
1110 | * @tsk: The task (thread) being checked. | |
f06febc9 | 1111 | * |
bb34d92f FM |
1112 | * Check the task and thread group timers. If both are zero (there are no |
1113 | * timers set) return false. Otherwise snapshot the task and thread group | |
1114 | * timers and compare them with the corresponding expiration times. Return | |
1115 | * true if a timer has expired, else return false. | |
f06febc9 | 1116 | */ |
bb34d92f | 1117 | static inline int fastpath_timer_check(struct task_struct *tsk) |
f06febc9 | 1118 | { |
ad133ba3 | 1119 | struct signal_struct *sig; |
6fac4829 FW |
1120 | cputime_t utime, stime; |
1121 | ||
1122 | task_cputime(tsk, &utime, &stime); | |
bb34d92f | 1123 | |
bb34d92f FM |
1124 | if (!task_cputime_zero(&tsk->cputime_expires)) { |
1125 | struct task_cputime task_sample = { | |
6fac4829 FW |
1126 | .utime = utime, |
1127 | .stime = stime, | |
bb34d92f FM |
1128 | .sum_exec_runtime = tsk->se.sum_exec_runtime |
1129 | }; | |
1130 | ||
1131 | if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) | |
1132 | return 1; | |
1133 | } | |
ad133ba3 ON |
1134 | |
1135 | sig = tsk->signal; | |
1018016c JL |
1136 | /* Check if cputimer is running. This is accessed without locking. */ |
1137 | if (READ_ONCE(sig->cputimer.running)) { | |
bb34d92f FM |
1138 | struct task_cputime group_sample; |
1139 | ||
71107445 | 1140 | sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic); |
8d1f431c | 1141 | |
bb34d92f FM |
1142 | if (task_cputime_expired(&group_sample, &sig->cputime_expires)) |
1143 | return 1; | |
1144 | } | |
37bebc70 | 1145 | |
f55db609 | 1146 | return 0; |
f06febc9 FM |
1147 | } |
1148 | ||
1da177e4 LT |
1149 | /* |
1150 | * This is called from the timer interrupt handler. The irq handler has | |
1151 | * already updated our counts. We need to check if any timers fire now. | |
1152 | * Interrupts are disabled. | |
1153 | */ | |
1154 | void run_posix_cpu_timers(struct task_struct *tsk) | |
1155 | { | |
1156 | LIST_HEAD(firing); | |
1157 | struct k_itimer *timer, *next; | |
0bdd2ed4 | 1158 | unsigned long flags; |
1da177e4 | 1159 | |
531f64fd | 1160 | WARN_ON_ONCE(!irqs_disabled()); |
1da177e4 | 1161 | |
1da177e4 | 1162 | /* |
f06febc9 | 1163 | * The fast path checks that there are no expired thread or thread |
bb34d92f | 1164 | * group timers. If that's so, just return. |
1da177e4 | 1165 | */ |
bb34d92f | 1166 | if (!fastpath_timer_check(tsk)) |
f06febc9 | 1167 | return; |
5ce73a4a | 1168 | |
0bdd2ed4 ON |
1169 | if (!lock_task_sighand(tsk, &flags)) |
1170 | return; | |
bb34d92f FM |
1171 | /* |
1172 | * Here we take off tsk->signal->cpu_timers[N] and | |
1173 | * tsk->cpu_timers[N] all the timers that are firing, and | |
1174 | * put them on the firing list. | |
1175 | */ | |
1176 | check_thread_timers(tsk, &firing); | |
29f87b79 SG |
1177 | /* |
1178 | * If there are any active process wide timers (POSIX 1.b, itimers, | |
1179 | * RLIMIT_CPU) cputimer must be running. | |
1180 | */ | |
1018016c | 1181 | if (READ_ONCE(tsk->signal->cputimer.running)) |
29f87b79 | 1182 | check_process_timers(tsk, &firing); |
1da177e4 | 1183 | |
bb34d92f FM |
1184 | /* |
1185 | * We must release these locks before taking any timer's lock. | |
1186 | * There is a potential race with timer deletion here, as the | |
1187 | * siglock now protects our private firing list. We have set | |
1188 | * the firing flag in each timer, so that a deletion attempt | |
1189 | * that gets the timer lock before we do will give it up and | |
1190 | * spin until we've taken care of that timer below. | |
1191 | */ | |
0bdd2ed4 | 1192 | unlock_task_sighand(tsk, &flags); |
1da177e4 LT |
1193 | |
1194 | /* | |
1195 | * Now that all the timers on our list have the firing flag, | |
25985edc | 1196 | * no one will touch their list entries but us. We'll take |
1da177e4 LT |
1197 | * each timer's lock before clearing its firing flag, so no |
1198 | * timer call will interfere. | |
1199 | */ | |
1200 | list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) { | |
6e85c5ba HS |
1201 | int cpu_firing; |
1202 | ||
1da177e4 LT |
1203 | spin_lock(&timer->it_lock); |
1204 | list_del_init(&timer->it.cpu.entry); | |
6e85c5ba | 1205 | cpu_firing = timer->it.cpu.firing; |
1da177e4 LT |
1206 | timer->it.cpu.firing = 0; |
1207 | /* | |
1208 | * The firing flag is -1 if we collided with a reset | |
1209 | * of the timer, which already reported this | |
1210 | * almost-firing as an overrun. So don't generate an event. | |
1211 | */ | |
6e85c5ba | 1212 | if (likely(cpu_firing >= 0)) |
1da177e4 | 1213 | cpu_timer_fire(timer); |
1da177e4 LT |
1214 | spin_unlock(&timer->it_lock); |
1215 | } | |
1216 | } | |
1217 | ||
1218 | /* | |
f55db609 | 1219 | * Set one of the process-wide special case CPU timers or RLIMIT_CPU. |
f06febc9 | 1220 | * The tsk->sighand->siglock must be held by the caller. |
1da177e4 LT |
1221 | */ |
1222 | void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, | |
1223 | cputime_t *newval, cputime_t *oldval) | |
1224 | { | |
55ccb616 | 1225 | unsigned long long now; |
1da177e4 | 1226 | |
531f64fd | 1227 | WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED); |
4cd4c1b4 | 1228 | cpu_timer_sample_group(clock_idx, tsk, &now); |
1da177e4 LT |
1229 | |
1230 | if (oldval) { | |
f55db609 SG |
1231 | /* |
1232 | * We are setting itimer. The *oldval is absolute and we update | |
1233 | * it to be relative, *newval argument is relative and we update | |
1234 | * it to be absolute. | |
1235 | */ | |
64861634 | 1236 | if (*oldval) { |
55ccb616 | 1237 | if (*oldval <= now) { |
1da177e4 | 1238 | /* Just about to fire. */ |
a42548a1 | 1239 | *oldval = cputime_one_jiffy; |
1da177e4 | 1240 | } else { |
55ccb616 | 1241 | *oldval -= now; |
1da177e4 LT |
1242 | } |
1243 | } | |
1244 | ||
64861634 | 1245 | if (!*newval) |
a8572160 | 1246 | goto out; |
55ccb616 | 1247 | *newval += now; |
1da177e4 LT |
1248 | } |
1249 | ||
1250 | /* | |
f55db609 SG |
1251 | * Update expiration cache if we are the earliest timer, or eventually |
1252 | * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire. | |
1da177e4 | 1253 | */ |
f55db609 SG |
1254 | switch (clock_idx) { |
1255 | case CPUCLOCK_PROF: | |
1256 | if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval)) | |
f06febc9 | 1257 | tsk->signal->cputime_expires.prof_exp = *newval; |
f55db609 SG |
1258 | break; |
1259 | case CPUCLOCK_VIRT: | |
1260 | if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval)) | |
f06febc9 | 1261 | tsk->signal->cputime_expires.virt_exp = *newval; |
f55db609 | 1262 | break; |
1da177e4 | 1263 | } |
a8572160 FW |
1264 | out: |
1265 | posix_cpu_timer_kick_nohz(); | |
1da177e4 LT |
1266 | } |
1267 | ||
e4b76555 TA |
1268 | static int do_cpu_nanosleep(const clockid_t which_clock, int flags, |
1269 | struct timespec *rqtp, struct itimerspec *it) | |
1da177e4 | 1270 | { |
1da177e4 LT |
1271 | struct k_itimer timer; |
1272 | int error; | |
1273 | ||
1da177e4 LT |
1274 | /* |
1275 | * Set up a temporary timer and then wait for it to go off. | |
1276 | */ | |
1277 | memset(&timer, 0, sizeof timer); | |
1278 | spin_lock_init(&timer.it_lock); | |
1279 | timer.it_clock = which_clock; | |
1280 | timer.it_overrun = -1; | |
1281 | error = posix_cpu_timer_create(&timer); | |
1282 | timer.it_process = current; | |
1283 | if (!error) { | |
1da177e4 | 1284 | static struct itimerspec zero_it; |
e4b76555 TA |
1285 | |
1286 | memset(it, 0, sizeof *it); | |
1287 | it->it_value = *rqtp; | |
1da177e4 LT |
1288 | |
1289 | spin_lock_irq(&timer.it_lock); | |
e4b76555 | 1290 | error = posix_cpu_timer_set(&timer, flags, it, NULL); |
1da177e4 LT |
1291 | if (error) { |
1292 | spin_unlock_irq(&timer.it_lock); | |
1293 | return error; | |
1294 | } | |
1295 | ||
1296 | while (!signal_pending(current)) { | |
55ccb616 | 1297 | if (timer.it.cpu.expires == 0) { |
1da177e4 | 1298 | /* |
e6c42c29 SG |
1299 | * Our timer fired and was reset, below |
1300 | * deletion can not fail. | |
1da177e4 | 1301 | */ |
e6c42c29 | 1302 | posix_cpu_timer_del(&timer); |
1da177e4 LT |
1303 | spin_unlock_irq(&timer.it_lock); |
1304 | return 0; | |
1305 | } | |
1306 | ||
1307 | /* | |
1308 | * Block until cpu_timer_fire (or a signal) wakes us. | |
1309 | */ | |
1310 | __set_current_state(TASK_INTERRUPTIBLE); | |
1311 | spin_unlock_irq(&timer.it_lock); | |
1312 | schedule(); | |
1313 | spin_lock_irq(&timer.it_lock); | |
1314 | } | |
1315 | ||
1316 | /* | |
1317 | * We were interrupted by a signal. | |
1318 | */ | |
1319 | sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); | |
e6c42c29 SG |
1320 | error = posix_cpu_timer_set(&timer, 0, &zero_it, it); |
1321 | if (!error) { | |
1322 | /* | |
1323 | * Timer is now unarmed, deletion can not fail. | |
1324 | */ | |
1325 | posix_cpu_timer_del(&timer); | |
1326 | } | |
1da177e4 LT |
1327 | spin_unlock_irq(&timer.it_lock); |
1328 | ||
e6c42c29 SG |
1329 | while (error == TIMER_RETRY) { |
1330 | /* | |
1331 | * We need to handle case when timer was or is in the | |
1332 | * middle of firing. In other cases we already freed | |
1333 | * resources. | |
1334 | */ | |
1335 | spin_lock_irq(&timer.it_lock); | |
1336 | error = posix_cpu_timer_del(&timer); | |
1337 | spin_unlock_irq(&timer.it_lock); | |
1338 | } | |
1339 | ||
e4b76555 | 1340 | if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { |
1da177e4 LT |
1341 | /* |
1342 | * It actually did fire already. | |
1343 | */ | |
1344 | return 0; | |
1345 | } | |
1346 | ||
e4b76555 TA |
1347 | error = -ERESTART_RESTARTBLOCK; |
1348 | } | |
1349 | ||
1350 | return error; | |
1351 | } | |
1352 | ||
bc2c8ea4 TG |
1353 | static long posix_cpu_nsleep_restart(struct restart_block *restart_block); |
1354 | ||
1355 | static int posix_cpu_nsleep(const clockid_t which_clock, int flags, | |
1356 | struct timespec *rqtp, struct timespec __user *rmtp) | |
e4b76555 | 1357 | { |
f56141e3 | 1358 | struct restart_block *restart_block = ¤t->restart_block; |
e4b76555 TA |
1359 | struct itimerspec it; |
1360 | int error; | |
1361 | ||
1362 | /* | |
1363 | * Diagnose required errors first. | |
1364 | */ | |
1365 | if (CPUCLOCK_PERTHREAD(which_clock) && | |
1366 | (CPUCLOCK_PID(which_clock) == 0 || | |
1367 | CPUCLOCK_PID(which_clock) == current->pid)) | |
1368 | return -EINVAL; | |
1369 | ||
1370 | error = do_cpu_nanosleep(which_clock, flags, rqtp, &it); | |
1371 | ||
1372 | if (error == -ERESTART_RESTARTBLOCK) { | |
1373 | ||
3751f9f2 | 1374 | if (flags & TIMER_ABSTIME) |
e4b76555 | 1375 | return -ERESTARTNOHAND; |
1da177e4 | 1376 | /* |
3751f9f2 TG |
1377 | * Report back to the user the time still remaining. |
1378 | */ | |
1379 | if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) | |
1da177e4 LT |
1380 | return -EFAULT; |
1381 | ||
1711ef38 | 1382 | restart_block->fn = posix_cpu_nsleep_restart; |
ab8177bc | 1383 | restart_block->nanosleep.clockid = which_clock; |
3751f9f2 TG |
1384 | restart_block->nanosleep.rmtp = rmtp; |
1385 | restart_block->nanosleep.expires = timespec_to_ns(rqtp); | |
1da177e4 | 1386 | } |
1da177e4 LT |
1387 | return error; |
1388 | } | |
1389 | ||
bc2c8ea4 | 1390 | static long posix_cpu_nsleep_restart(struct restart_block *restart_block) |
1da177e4 | 1391 | { |
ab8177bc | 1392 | clockid_t which_clock = restart_block->nanosleep.clockid; |
97735f25 | 1393 | struct timespec t; |
e4b76555 TA |
1394 | struct itimerspec it; |
1395 | int error; | |
97735f25 | 1396 | |
3751f9f2 | 1397 | t = ns_to_timespec(restart_block->nanosleep.expires); |
97735f25 | 1398 | |
e4b76555 TA |
1399 | error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); |
1400 | ||
1401 | if (error == -ERESTART_RESTARTBLOCK) { | |
3751f9f2 | 1402 | struct timespec __user *rmtp = restart_block->nanosleep.rmtp; |
e4b76555 | 1403 | /* |
3751f9f2 TG |
1404 | * Report back to the user the time still remaining. |
1405 | */ | |
1406 | if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) | |
e4b76555 TA |
1407 | return -EFAULT; |
1408 | ||
3751f9f2 | 1409 | restart_block->nanosleep.expires = timespec_to_ns(&t); |
e4b76555 TA |
1410 | } |
1411 | return error; | |
1412 | ||
1da177e4 LT |
1413 | } |
1414 | ||
1da177e4 LT |
1415 | #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) |
1416 | #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) | |
1417 | ||
a924b04d TG |
1418 | static int process_cpu_clock_getres(const clockid_t which_clock, |
1419 | struct timespec *tp) | |
1da177e4 LT |
1420 | { |
1421 | return posix_cpu_clock_getres(PROCESS_CLOCK, tp); | |
1422 | } | |
a924b04d TG |
1423 | static int process_cpu_clock_get(const clockid_t which_clock, |
1424 | struct timespec *tp) | |
1da177e4 LT |
1425 | { |
1426 | return posix_cpu_clock_get(PROCESS_CLOCK, tp); | |
1427 | } | |
1428 | static int process_cpu_timer_create(struct k_itimer *timer) | |
1429 | { | |
1430 | timer->it_clock = PROCESS_CLOCK; | |
1431 | return posix_cpu_timer_create(timer); | |
1432 | } | |
a924b04d | 1433 | static int process_cpu_nsleep(const clockid_t which_clock, int flags, |
97735f25 TG |
1434 | struct timespec *rqtp, |
1435 | struct timespec __user *rmtp) | |
1da177e4 | 1436 | { |
97735f25 | 1437 | return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp); |
1da177e4 | 1438 | } |
1711ef38 TA |
1439 | static long process_cpu_nsleep_restart(struct restart_block *restart_block) |
1440 | { | |
1441 | return -EINVAL; | |
1442 | } | |
a924b04d TG |
1443 | static int thread_cpu_clock_getres(const clockid_t which_clock, |
1444 | struct timespec *tp) | |
1da177e4 LT |
1445 | { |
1446 | return posix_cpu_clock_getres(THREAD_CLOCK, tp); | |
1447 | } | |
a924b04d TG |
1448 | static int thread_cpu_clock_get(const clockid_t which_clock, |
1449 | struct timespec *tp) | |
1da177e4 LT |
1450 | { |
1451 | return posix_cpu_clock_get(THREAD_CLOCK, tp); | |
1452 | } | |
1453 | static int thread_cpu_timer_create(struct k_itimer *timer) | |
1454 | { | |
1455 | timer->it_clock = THREAD_CLOCK; | |
1456 | return posix_cpu_timer_create(timer); | |
1457 | } | |
1da177e4 | 1458 | |
1976945e TG |
1459 | struct k_clock clock_posix_cpu = { |
1460 | .clock_getres = posix_cpu_clock_getres, | |
1461 | .clock_set = posix_cpu_clock_set, | |
1462 | .clock_get = posix_cpu_clock_get, | |
1463 | .timer_create = posix_cpu_timer_create, | |
1464 | .nsleep = posix_cpu_nsleep, | |
1465 | .nsleep_restart = posix_cpu_nsleep_restart, | |
1466 | .timer_set = posix_cpu_timer_set, | |
1467 | .timer_del = posix_cpu_timer_del, | |
1468 | .timer_get = posix_cpu_timer_get, | |
1469 | }; | |
1470 | ||
1da177e4 LT |
1471 | static __init int init_posix_cpu_timers(void) |
1472 | { | |
1473 | struct k_clock process = { | |
2fd1f040 TG |
1474 | .clock_getres = process_cpu_clock_getres, |
1475 | .clock_get = process_cpu_clock_get, | |
2fd1f040 TG |
1476 | .timer_create = process_cpu_timer_create, |
1477 | .nsleep = process_cpu_nsleep, | |
1478 | .nsleep_restart = process_cpu_nsleep_restart, | |
1da177e4 LT |
1479 | }; |
1480 | struct k_clock thread = { | |
2fd1f040 TG |
1481 | .clock_getres = thread_cpu_clock_getres, |
1482 | .clock_get = thread_cpu_clock_get, | |
2fd1f040 | 1483 | .timer_create = thread_cpu_timer_create, |
1da177e4 | 1484 | }; |
8356b5f9 | 1485 | struct timespec ts; |
1da177e4 | 1486 | |
52708737 TG |
1487 | posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process); |
1488 | posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread); | |
1da177e4 | 1489 | |
a42548a1 | 1490 | cputime_to_timespec(cputime_one_jiffy, &ts); |
8356b5f9 SG |
1491 | onecputick = ts.tv_nsec; |
1492 | WARN_ON(ts.tv_sec != 0); | |
1493 | ||
1da177e4 LT |
1494 | return 0; |
1495 | } | |
1496 | __initcall(init_posix_cpu_timers); |