diff options
Diffstat (limited to 'kernel/posix-cpu-timers.c')
-rw-r--r-- | kernel/posix-cpu-timers.c | 733 |
1 files changed, 322 insertions, 411 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 05bb7173850e..c7f31aa272f7 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -9,6 +9,9 @@ #include <asm/uaccess.h> #include <linux/kernel_stat.h> #include <trace/events/timer.h> +#include <linux/random.h> +#include <linux/tick.h> +#include <linux/workqueue.h> /* * Called after updating RLIMIT_CPU to run cpu timer and update @@ -48,72 +51,28 @@ static int check_clock(const clockid_t which_clock) return error; } -static inline union cpu_time_count +static inline unsigned long long timespec_to_sample(const clockid_t which_clock, const struct timespec *tp) { - union cpu_time_count ret; - ret.sched = 0; /* high half always zero when .cpu used */ + unsigned long long ret; + + ret = 0; /* high half always zero when .cpu used */ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { - ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; + ret = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; } else { - ret.cpu = timespec_to_cputime(tp); + ret = cputime_to_expires(timespec_to_cputime(tp)); } return ret; } static void sample_to_timespec(const clockid_t which_clock, - union cpu_time_count cpu, + unsigned long long expires, struct timespec *tp) { if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) - *tp = ns_to_timespec(cpu.sched); + *tp = ns_to_timespec(expires); else - cputime_to_timespec(cpu.cpu, tp); -} - -static inline int cpu_time_before(const clockid_t which_clock, - union cpu_time_count now, - union cpu_time_count then) -{ - if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { - return now.sched < then.sched; - } else { - return cputime_lt(now.cpu, then.cpu); - } -} -static inline void cpu_time_add(const clockid_t which_clock, - union cpu_time_count *acc, - union cpu_time_count val) -{ - if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { - acc->sched += val.sched; - } else { - acc->cpu = cputime_add(acc->cpu, val.cpu); - } -} -static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock, - union cpu_time_count a, - union cpu_time_count b) -{ - if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { - a.sched -= b.sched; - } else { - a.cpu = cputime_sub(a.cpu, b.cpu); - } - return a; -} - -/* - * Divide and limit the result to res >= 1 - * - * This is necessary to prevent signal delivery starvation, when the result of - * the division would be rounded down to 0. - */ -static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div) -{ - cputime_t res = cputime_div(time, div); - - return max_t(cputime_t, res, 1); + cputime_to_timespec((__force cputime_t)expires, tp); } /* @@ -121,62 +80,68 @@ static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div) * given the current clock sample. */ static void bump_cpu_timer(struct k_itimer *timer, - union cpu_time_count now) + unsigned long long now) { int i; + unsigned long long delta, incr; - if (timer->it.cpu.incr.sched == 0) + if (timer->it.cpu.incr == 0) return; - if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) { - unsigned long long delta, incr; + if (now < timer->it.cpu.expires) + return; - if (now.sched < timer->it.cpu.expires.sched) - return; - incr = timer->it.cpu.incr.sched; - delta = now.sched + incr - timer->it.cpu.expires.sched; - /* Don't use (incr*2 < delta), incr*2 might overflow. */ - for (i = 0; incr < delta - incr; i++) - incr = incr << 1; - for (; i >= 0; incr >>= 1, i--) { - if (delta < incr) - continue; - timer->it.cpu.expires.sched += incr; - timer->it_overrun += 1 << i; - delta -= incr; - } - } else { - cputime_t delta, incr; + incr = timer->it.cpu.incr; + delta = now + incr - timer->it.cpu.expires; - if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu)) - return; - incr = timer->it.cpu.incr.cpu; - delta = cputime_sub(cputime_add(now.cpu, incr), - timer->it.cpu.expires.cpu); - /* Don't use (incr*2 < delta), incr*2 might overflow. */ - for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++) - incr = cputime_add(incr, incr); - for (; i >= 0; incr = cputime_halve(incr), i--) { - if (cputime_lt(delta, incr)) - continue; - timer->it.cpu.expires.cpu = - cputime_add(timer->it.cpu.expires.cpu, incr); - timer->it_overrun += 1 << i; - delta = cputime_sub(delta, incr); - } + /* Don't use (incr*2 < delta), incr*2 might overflow. */ + for (i = 0; incr < delta - incr; i++) + incr = incr << 1; + + for (; i >= 0; incr >>= 1, i--) { + if (delta < incr) + continue; + + timer->it.cpu.expires += incr; + timer->it_overrun += 1 << i; + delta -= incr; } } -static inline cputime_t prof_ticks(struct task_struct *p) +/** + * task_cputime_zero - Check a task_cputime struct for all zero fields. + * + * @cputime: The struct to compare. + * + * Checks @cputime to see if all fields are zero. Returns true if all fields + * are zero, false if any field is nonzero. + */ +static inline int task_cputime_zero(const struct task_cputime *cputime) +{ + if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) + return 1; + return 0; +} + +static inline unsigned long long prof_ticks(struct task_struct *p) { - return cputime_add(p->utime, p->stime); + cputime_t utime, stime; + + task_cputime(p, &utime, &stime); + + return cputime_to_expires(utime + stime); } -static inline cputime_t virt_ticks(struct task_struct *p) +static inline unsigned long long virt_ticks(struct task_struct *p) { - return p->utime; + cputime_t utime; + + task_cputime(p, &utime, NULL); + + return cputime_to_expires(utime); } -int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) +static int +posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) { int error = check_clock(which_clock); if (!error) { @@ -194,7 +159,8 @@ int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) return error; } -int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) +static int +posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) { /* * You can never reset a CPU clock, but we check for other errors @@ -212,54 +178,30 @@ int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) * Sample a per-thread clock for the given task. */ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, - union cpu_time_count *cpu) + unsigned long long *sample) { switch (CPUCLOCK_WHICH(which_clock)) { default: return -EINVAL; case CPUCLOCK_PROF: - cpu->cpu = prof_ticks(p); + *sample = prof_ticks(p); break; case CPUCLOCK_VIRT: - cpu->cpu = virt_ticks(p); + *sample = virt_ticks(p); break; case CPUCLOCK_SCHED: - cpu->sched = task_sched_runtime(p); + *sample = task_sched_runtime(p); break; } return 0; } -void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) -{ - struct signal_struct *sig = tsk->signal; - struct task_struct *t; - - times->utime = sig->utime; - times->stime = sig->stime; - times->sum_exec_runtime = sig->sum_sched_runtime; - - rcu_read_lock(); - /* make sure we can trust tsk->thread_group list */ - if (!likely(pid_alive(tsk))) - goto out; - - t = tsk; - do { - times->utime = cputime_add(times->utime, t->utime); - times->stime = cputime_add(times->stime, t->stime); - times->sum_exec_runtime += t->se.sum_exec_runtime; - } while_each_thread(tsk, t); -out: - rcu_read_unlock(); -} - static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b) { - if (cputime_gt(b->utime, a->utime)) + if (b->utime > a->utime) a->utime = b->utime; - if (cputime_gt(b->stime, a->stime)) + if (b->stime > a->stime) a->stime = b->stime; if (b->sum_exec_runtime > a->sum_exec_runtime) @@ -272,9 +214,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) struct task_cputime sum; unsigned long flags; - spin_lock_irqsave(&cputimer->lock, flags); if (!cputimer->running) { - cputimer->running = 1; /* * The POSIX timer interface allows for absolute time expiry * values through the TIMER_ABSTIME flag, therefore we have @@ -282,10 +222,13 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) * it. */ thread_group_cputime(tsk, &sum); + raw_spin_lock_irqsave(&cputimer->lock, flags); + cputimer->running = 1; update_gt_cputime(&cputimer->cputime, &sum); - } + } else + raw_spin_lock_irqsave(&cputimer->lock, flags); *times = cputimer->cputime; - spin_unlock_irqrestore(&cputimer->lock, flags); + raw_spin_unlock_irqrestore(&cputimer->lock, flags); } /* @@ -294,7 +237,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) */ static int cpu_clock_sample_group(const clockid_t which_clock, struct task_struct *p, - union cpu_time_count *cpu) + unsigned long long *sample) { struct task_cputime cputime; @@ -303,25 +246,26 @@ static int cpu_clock_sample_group(const clockid_t which_clock, return -EINVAL; case CPUCLOCK_PROF: thread_group_cputime(p, &cputime); - cpu->cpu = cputime_add(cputime.utime, cputime.stime); + *sample = cputime_to_expires(cputime.utime + cputime.stime); break; case CPUCLOCK_VIRT: thread_group_cputime(p, &cputime); - cpu->cpu = cputime.utime; + *sample = cputime_to_expires(cputime.utime); break; case CPUCLOCK_SCHED: - cpu->sched = thread_group_sched_runtime(p); + thread_group_cputime(p, &cputime); + *sample = cputime.sum_exec_runtime; break; } return 0; } -int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) +static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) { const pid_t pid = CPUCLOCK_PID(which_clock); int error = -EINVAL; - union cpu_time_count rtn; + unsigned long long rtn; if (pid == 0) { /* @@ -379,7 +323,7 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) * This is called from sys_timer_create() and do_cpu_nanosleep() with the * new timer already all-zeros initialized. */ -int posix_cpu_timer_create(struct k_itimer *new_timer) +static int posix_cpu_timer_create(struct k_itimer *new_timer) { int ret = 0; const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); @@ -425,7 +369,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) * If we return TIMER_RETRY, it's necessary to release the timer's lock * and try again. (This happens when the timer is in the middle of firing.) */ -int posix_cpu_timer_del(struct k_itimer *timer) +static int posix_cpu_timer_del(struct k_itimer *timer) { struct task_struct *p = timer->it.cpu.task; int ret = 0; @@ -455,6 +399,15 @@ int posix_cpu_timer_del(struct k_itimer *timer) return ret; } +static void cleanup_timers_list(struct list_head *head, + unsigned long long curr) +{ + struct cpu_timer_list *timer, *next; + + list_for_each_entry_safe(timer, next, head, entry) + list_del_init(&timer->entry); +} + /* * Clean out CPU timers still ticking when a thread exited. The task * pointer is cleared, and the expiry time is replaced with the residual @@ -465,39 +418,12 @@ static void cleanup_timers(struct list_head *head, cputime_t utime, cputime_t stime, unsigned long long sum_exec_runtime) { - struct cpu_timer_list *timer, *next; - cputime_t ptime = cputime_add(utime, stime); - list_for_each_entry_safe(timer, next, head, entry) { - list_del_init(&timer->entry); - if (cputime_lt(timer->expires.cpu, ptime)) { - timer->expires.cpu = cputime_zero; - } else { - timer->expires.cpu = cputime_sub(timer->expires.cpu, - ptime); - } - } - - ++head; - list_for_each_entry_safe(timer, next, head, entry) { - list_del_init(&timer->entry); - if (cputime_lt(timer->expires.cpu, utime)) { - timer->expires.cpu = cputime_zero; - } else { - timer->expires.cpu = cputime_sub(timer->expires.cpu, - utime); - } - } + cputime_t ptime = utime + stime; - ++head; - list_for_each_entry_safe(timer, next, head, entry) { - list_del_init(&timer->entry); - if (timer->expires.sched < sum_exec_runtime) { - timer->expires.sched = 0; - } else { - timer->expires.sched -= sum_exec_runtime; - } - } + cleanup_timers_list(head, cputime_to_expires(ptime)); + cleanup_timers_list(++head, cputime_to_expires(utime)); + cleanup_timers_list(++head, sum_exec_runtime); } /* @@ -507,37 +433,46 @@ static void cleanup_timers(struct list_head *head, */ void posix_cpu_timers_exit(struct task_struct *tsk) { + cputime_t utime, stime; + + add_device_randomness((const void*) &tsk->se.sum_exec_runtime, + sizeof(unsigned long long)); + task_cputime(tsk, &utime, &stime); cleanup_timers(tsk->cpu_timers, - tsk->utime, tsk->stime, tsk->se.sum_exec_runtime); + utime, stime, tsk->se.sum_exec_runtime); } void posix_cpu_timers_exit_group(struct task_struct *tsk) { struct signal_struct *const sig = tsk->signal; + cputime_t utime, stime; + task_cputime(tsk, &utime, &stime); cleanup_timers(tsk->signal->cpu_timers, - cputime_add(tsk->utime, sig->utime), - cputime_add(tsk->stime, sig->stime), + utime + sig->utime, stime + sig->stime, tsk->se.sum_exec_runtime + sig->sum_sched_runtime); } -static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now) +static void clear_dead_task(struct k_itimer *itimer, unsigned long long now) { + struct cpu_timer_list *timer = &itimer->it.cpu; + /* * That's all for this thread or process. * We leave our residual in expires to be reported. */ - put_task_struct(timer->it.cpu.task); - timer->it.cpu.task = NULL; - timer->it.cpu.expires = cpu_time_sub(timer->it_clock, - timer->it.cpu.expires, - now); + put_task_struct(timer->task); + timer->task = NULL; + if (timer->expires < now) { + timer->expires = 0; + } else { + timer->expires -= now; + } } static inline int expires_gt(cputime_t expires, cputime_t new_exp) { - return cputime_eq(expires, cputime_zero) || - cputime_gt(expires, new_exp); + return expires == 0 || expires > new_exp; } /* @@ -564,14 +499,14 @@ static void arm_timer(struct k_itimer *timer) listpos = head; list_for_each_entry(next, head, entry) { - if (cpu_time_before(timer->it_clock, nt->expires, next->expires)) + if (nt->expires < next->expires) break; listpos = &next->entry; } list_add(&nt->entry, listpos); if (listpos == head) { - union cpu_time_count *exp = &nt->expires; + unsigned long long exp = nt->expires; /* * We are the new earliest-expiring POSIX 1.b timer, hence @@ -582,17 +517,17 @@ static void arm_timer(struct k_itimer *timer) switch (CPUCLOCK_WHICH(timer->it_clock)) { case CPUCLOCK_PROF: - if (expires_gt(cputime_expires->prof_exp, exp->cpu)) - cputime_expires->prof_exp = exp->cpu; + if (expires_gt(cputime_expires->prof_exp, expires_to_cputime(exp))) + cputime_expires->prof_exp = expires_to_cputime(exp); break; case CPUCLOCK_VIRT: - if (expires_gt(cputime_expires->virt_exp, exp->cpu)) - cputime_expires->virt_exp = exp->cpu; + if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp))) + cputime_expires->virt_exp = expires_to_cputime(exp); break; case CPUCLOCK_SCHED: if (cputime_expires->sched_exp == 0 || - cputime_expires->sched_exp > exp->sched) - cputime_expires->sched_exp = exp->sched; + cputime_expires->sched_exp > exp) + cputime_expires->sched_exp = exp; break; } } @@ -607,20 +542,20 @@ static void cpu_timer_fire(struct k_itimer *timer) /* * User don't want any signal. */ - timer->it.cpu.expires.sched = 0; + timer->it.cpu.expires = 0; } else if (unlikely(timer->sigq == NULL)) { /* * This a special case for clock_nanosleep, * not a normal timer from sys_timer_create. */ wake_up_process(timer->it_process); - timer->it.cpu.expires.sched = 0; - } else if (timer->it.cpu.incr.sched == 0) { + timer->it.cpu.expires = 0; + } else if (timer->it.cpu.incr == 0) { /* * One-shot timer. Clear it as soon as it's fired. */ posix_timer_event(timer, 0); - timer->it.cpu.expires.sched = 0; + timer->it.cpu.expires = 0; } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { /* * The signal did not get queued because the signal @@ -638,7 +573,7 @@ static void cpu_timer_fire(struct k_itimer *timer) */ static int cpu_timer_sample_group(const clockid_t which_clock, struct task_struct *p, - union cpu_time_count *cpu) + unsigned long long *sample) { struct task_cputime cputime; @@ -647,29 +582,60 @@ static int cpu_timer_sample_group(const clockid_t which_clock, default: return -EINVAL; case CPUCLOCK_PROF: - cpu->cpu = cputime_add(cputime.utime, cputime.stime); + *sample = cputime_to_expires(cputime.utime + cputime.stime); break; case CPUCLOCK_VIRT: - cpu->cpu = cputime.utime; + *sample = cputime_to_expires(cputime.utime); break; case CPUCLOCK_SCHED: - cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p); + *sample = cputime.sum_exec_runtime + task_delta_exec(p); break; } return 0; } +#ifdef CONFIG_NO_HZ_FULL +static void nohz_kick_work_fn(struct work_struct *work) +{ + tick_nohz_full_kick_all(); +} + +static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn); + +/* + * We need the IPIs to be sent from sane process context. + * The posix cpu timers are always set with irqs disabled. + */ +static void posix_cpu_timer_kick_nohz(void) +{ + schedule_work(&nohz_kick_work); +} + +bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk) +{ + if (!task_cputime_zero(&tsk->cputime_expires)) + return false; + + if (tsk->signal->cputimer.running) + return false; + + return true; +} +#else +static inline void posix_cpu_timer_kick_nohz(void) { } +#endif + /* * Guts of sys_timer_settime for CPU timers. * This is called with the timer locked and interrupts disabled. * If we return TIMER_RETRY, it's necessary to release the timer's lock * and try again. (This happens when the timer is in the middle of firing.) */ -int posix_cpu_timer_set(struct k_itimer *timer, int flags, - struct itimerspec *new, struct itimerspec *old) +static int posix_cpu_timer_set(struct k_itimer *timer, int flags, + struct itimerspec *new, struct itimerspec *old) { struct task_struct *p = timer->it.cpu.task; - union cpu_time_count old_expires, new_expires, old_incr, val; + unsigned long long old_expires, new_expires, old_incr, val; int ret; if (unlikely(p == NULL)) { @@ -724,7 +690,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, } if (old) { - if (old_expires.sched == 0) { + if (old_expires == 0) { old->it_value.tv_sec = 0; old->it_value.tv_nsec = 0; } else { @@ -739,11 +705,8 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, * new setting. */ bump_cpu_timer(timer, val); - if (cpu_time_before(timer->it_clock, val, - timer->it.cpu.expires)) { - old_expires = cpu_time_sub( - timer->it_clock, - timer->it.cpu.expires, val); + if (val < timer->it.cpu.expires) { + old_expires = timer->it.cpu.expires - val; sample_to_timespec(timer->it_clock, old_expires, &old->it_value); @@ -766,8 +729,8 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, goto out; } - if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) { - cpu_time_add(timer->it_clock, &new_expires, val); + if (new_expires != 0 && !(flags & TIMER_ABSTIME)) { + new_expires += val; } /* @@ -776,8 +739,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, * arm the timer (we'll just fake it for timer_gettime). */ timer->it.cpu.expires = new_expires; - if (new_expires.sched != 0 && - cpu_time_before(timer->it_clock, val, new_expires)) { + if (new_expires != 0 && val < new_expires) { arm_timer(timer); } @@ -801,8 +763,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, timer->it_overrun_last = 0; timer->it_overrun = -1; - if (new_expires.sched != 0 && - !cpu_time_before(timer->it_clock, val, new_expires)) { + if (new_expires != 0 && !(val < new_expires)) { /* * The designated time already passed, so we notify * immediately, even if the thread never runs to @@ -817,12 +778,14 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, sample_to_timespec(timer->it_clock, old_incr, &old->it_interval); } + if (!ret) + posix_cpu_timer_kick_nohz(); return ret; } -void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) +static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) { - union cpu_time_count now; + unsigned long long now; struct task_struct *p = timer->it.cpu.task; int clear_dead; @@ -832,7 +795,7 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) sample_to_timespec(timer->it_clock, timer->it.cpu.incr, &itp->it_interval); - if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */ + if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */ itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; return; } @@ -864,7 +827,7 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) */ put_task_struct(p); timer->it.cpu.task = NULL; - timer->it.cpu.expires.sched = 0; + timer->it.cpu.expires = 0; read_unlock(&tasklist_lock); goto dead; } else { @@ -885,10 +848,9 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) goto dead; } - if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) { + if (now < timer->it.cpu.expires) { sample_to_timespec(timer->it_clock, - cpu_time_sub(timer->it_clock, - timer->it.cpu.expires, now), + timer->it.cpu.expires - now, &itp->it_value); } else { /* @@ -900,6 +862,28 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) } } +static unsigned long long +check_timers_list(struct list_head *timers, + struct list_head *firing, + unsigned long long curr) +{ + int maxfire = 20; + + while (!list_empty(timers)) { + struct cpu_timer_list *t; + + t = list_first_entry(timers, struct cpu_timer_list, entry); + + if (!--maxfire || curr < t->expires) + return t->expires; + + t->firing = 1; + list_move_tail(&t->entry, firing); + } + + return 0; +} + /* * Check for any per-thread CPU timers that have fired and move them off * the tsk->cpu_timers[N] list onto the firing list. Here we update the @@ -908,54 +892,20 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) static void check_thread_timers(struct task_struct *tsk, struct list_head *firing) { - int maxfire; struct list_head *timers = tsk->cpu_timers; struct signal_struct *const sig = tsk->signal; + struct task_cputime *tsk_expires = &tsk->cputime_expires; + unsigned long long expires; unsigned long soft; - maxfire = 20; - tsk->cputime_expires.prof_exp = cputime_zero; - while (!list_empty(timers)) { - struct cpu_timer_list *t = list_first_entry(timers, - struct cpu_timer_list, - entry); - if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) { - tsk->cputime_expires.prof_exp = t->expires.cpu; - break; - } - t->firing = 1; - list_move_tail(&t->entry, firing); - } + expires = check_timers_list(timers, firing, prof_ticks(tsk)); + tsk_expires->prof_exp = expires_to_cputime(expires); - ++timers; - maxfire = 20; - tsk->cputime_expires.virt_exp = cputime_zero; - while (!list_empty(timers)) { - struct cpu_timer_list *t = list_first_entry(timers, - struct cpu_timer_list, - entry); - if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) { - tsk->cputime_expires.virt_exp = t->expires.cpu; - break; - } - t->firing = 1; - list_move_tail(&t->entry, firing); - } + expires = check_timers_list(++timers, firing, virt_ticks(tsk)); + tsk_expires->virt_exp = expires_to_cputime(expires); - ++timers; - maxfire = 20; - tsk->cputime_expires.sched_exp = 0; - while (!list_empty(timers)) { - struct cpu_timer_list *t = list_first_entry(timers, - struct cpu_timer_list, - entry); - if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) { - tsk->cputime_expires.sched_exp = t->expires.sched; - break; - } - t->firing = 1; - list_move_tail(&t->entry, firing); - } + tsk_expires->sched_exp = check_timers_list(++timers, firing, + tsk->se.sum_exec_runtime); /* * Check for the special case thread timers. @@ -995,30 +945,30 @@ static void stop_process_timers(struct signal_struct *sig) struct thread_group_cputimer *cputimer = &sig->cputimer; unsigned long flags; - spin_lock_irqsave(&cputimer->lock, flags); + raw_spin_lock_irqsave(&cputimer->lock, flags); cputimer->running = 0; - spin_unlock_irqrestore(&cputimer->lock, flags); + raw_spin_unlock_irqrestore(&cputimer->lock, flags); } static u32 onecputick; static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, - cputime_t *expires, cputime_t cur_time, int signo) + unsigned long long *expires, + unsigned long long cur_time, int signo) { - if (cputime_eq(it->expires, cputime_zero)) + if (!it->expires) return; - if (cputime_ge(cur_time, it->expires)) { - if (!cputime_eq(it->incr, cputime_zero)) { - it->expires = cputime_add(it->expires, it->incr); + if (cur_time >= it->expires) { + if (it->incr) { + it->expires += it->incr; it->error += it->incr_error; if (it->error >= onecputick) { - it->expires = cputime_sub(it->expires, - cputime_one_jiffy); + it->expires -= cputime_one_jiffy; it->error -= onecputick; } } else { - it->expires = cputime_zero; + it->expires = 0; } trace_itimer_expire(signo == SIGPROF ? @@ -1027,30 +977,11 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } - if (!cputime_eq(it->expires, cputime_zero) && - (cputime_eq(*expires, cputime_zero) || - cputime_lt(it->expires, *expires))) { + if (it->expires && (!*expires || it->expires < *expires)) { *expires = it->expires; } } -/** - * task_cputime_zero - Check a task_cputime struct for all zero fields. - * - * @cputime: The struct to compare. - * - * Checks @cputime to see if all fields are zero. Returns true if all fields - * are zero, false if any field is nonzero. - */ -static inline int task_cputime_zero(const struct task_cputime *cputime) -{ - if (cputime_eq(cputime->utime, cputime_zero) && - cputime_eq(cputime->stime, cputime_zero) && - cputime->sum_exec_runtime == 0) - return 1; - return 0; -} - /* * Check for any per-thread CPU timers that have fired and move them * off the tsk->*_timers list onto the firing list. Per-thread timers @@ -1059,9 +990,8 @@ static inline int task_cputime_zero(const struct task_cputime *cputime) static void check_process_timers(struct task_struct *tsk, struct list_head *firing) { - int maxfire; struct signal_struct *const sig = tsk->signal; - cputime_t utime, ptime, virt_expires, prof_expires; + unsigned long long utime, ptime, virt_expires, prof_expires; unsigned long long sum_sched_runtime, sched_expires; struct list_head *timers = sig->cpu_timers; struct task_cputime cputime; @@ -1071,52 +1001,13 @@ static void check_process_timers(struct task_struct *tsk, * Collect the current process totals. */ thread_group_cputimer(tsk, &cputime); - utime = cputime.utime; - ptime = cputime_add(utime, cputime.stime); + utime = cputime_to_expires(cputime.utime); + ptime = utime + cputime_to_expires(cputime.stime); sum_sched_runtime = cputime.sum_exec_runtime; - maxfire = 20; - prof_expires = cputime_zero; - while (!list_empty(timers)) { - struct cpu_timer_list *tl = list_first_entry(timers, - struct cpu_timer_list, - entry); - if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) { - prof_expires = tl->expires.cpu; - break; - } - tl->firing = 1; - list_move_tail(&tl->entry, firing); - } - - ++timers; - maxfire = 20; - virt_expires = cputime_zero; - while (!list_empty(timers)) { - struct cpu_timer_list *tl = list_first_entry(timers, - struct cpu_timer_list, - entry); - if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) { - virt_expires = tl->expires.cpu; - break; - } - tl->firing = 1; - list_move_tail(&tl->entry, firing); - } - ++timers; - maxfire = 20; - sched_expires = 0; - while (!list_empty(timers)) { - struct cpu_timer_list *tl = list_first_entry(timers, - struct cpu_timer_list, - entry); - if (!--maxfire || sum_sched_runtime < tl->expires.sched) { - sched_expires = tl->expires.sched; - break; - } - tl->firing = 1; - list_move_tail(&tl->entry, firing); - } + prof_expires = check_timers_list(timers, firing, ptime); + virt_expires = check_timers_list(++timers, firing, utime); + sched_expires = check_timers_list(++timers, firing, sum_sched_runtime); /* * Check for the special case process timers. @@ -1150,14 +1041,13 @@ static void check_process_timers(struct task_struct *tsk, } } x = secs_to_cputime(soft); - if (cputime_eq(prof_expires, cputime_zero) || - cputime_lt(x, prof_expires)) { + if (!prof_expires || x < prof_expires) { prof_expires = x; } } - sig->cputime_expires.prof_exp = prof_expires; - sig->cputime_expires.virt_exp = virt_expires; + sig->cputime_expires.prof_exp = expires_to_cputime(prof_expires); + sig->cputime_expires.virt_exp = expires_to_cputime(virt_expires); sig->cputime_expires.sched_exp = sched_expires; if (task_cputime_zero(&sig->cputime_expires)) stop_process_timers(sig); @@ -1170,7 +1060,7 @@ static void check_process_timers(struct task_struct *tsk, void posix_cpu_timer_schedule(struct k_itimer *timer) { struct task_struct *p = timer->it.cpu.task; - union cpu_time_count now; + unsigned long long now; if (unlikely(p == NULL)) /* @@ -1199,7 +1089,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer) */ put_task_struct(p); timer->it.cpu.task = p = NULL; - timer->it.cpu.expires.sched = 0; + timer->it.cpu.expires = 0; goto out_unlock; } else if (unlikely(p->exit_state) && thread_group_empty(p)) { /* @@ -1207,6 +1097,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer) * not yet reaped. Take this opportunity to * drop our task ref. */ + cpu_timer_sample_group(timer->it_clock, p, &now); clear_dead_task(timer, now); goto out_unlock; } @@ -1245,12 +1136,9 @@ out: static inline int task_cputime_expired(const struct task_cputime *sample, const struct task_cputime *expires) { - if (!cputime_eq(expires->utime, cputime_zero) && - cputime_ge(sample->utime, expires->utime)) + if (expires->utime && sample->utime >= expires->utime) return 1; - if (!cputime_eq(expires->stime, cputime_zero) && - cputime_ge(cputime_add(sample->utime, sample->stime), - expires->stime)) + if (expires->stime && sample->utime + sample->stime >= expires->stime) return 1; if (expires->sum_exec_runtime != 0 && sample->sum_exec_runtime >= expires->sum_exec_runtime) @@ -1271,11 +1159,14 @@ static inline int task_cputime_expired(const struct task_cputime *sample, static inline int fastpath_timer_check(struct task_struct *tsk) { struct signal_struct *sig; + cputime_t utime, stime; + + task_cputime(tsk, &utime, &stime); if (!task_cputime_zero(&tsk->cputime_expires)) { struct task_cputime task_sample = { - .utime = tsk->utime, - .stime = tsk->stime, + .utime = utime, + .stime = stime, .sum_exec_runtime = tsk->se.sum_exec_runtime }; @@ -1287,9 +1178,9 @@ static inline int fastpath_timer_check(struct task_struct *tsk) if (sig->cputimer.running) { struct task_cputime group_sample; - spin_lock(&sig->cputimer.lock); + raw_spin_lock(&sig->cputimer.lock); group_sample = sig->cputimer.cputime; - spin_unlock(&sig->cputimer.lock); + raw_spin_unlock(&sig->cputimer.lock); if (task_cputime_expired(&group_sample, &sig->cputime_expires)) return 1; @@ -1345,7 +1236,7 @@ void run_posix_cpu_timers(struct task_struct *tsk) /* * Now that all the timers on our list have the firing flag, - * noone will touch their list entries but us. We'll take + * no one will touch their list entries but us. We'll take * each timer's lock before clearing its firing flag, so no * timer call will interfere. */ @@ -1365,6 +1256,13 @@ void run_posix_cpu_timers(struct task_struct *tsk) cpu_timer_fire(timer); spin_unlock(&timer->it_lock); } + + /* + * In case some timers were rescheduled after the queue got emptied, + * wake up full dynticks CPUs. + */ + if (tsk->signal->cputimer.running) + posix_cpu_timer_kick_nohz(); } /* @@ -1374,7 +1272,7 @@ void run_posix_cpu_timers(struct task_struct *tsk) void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, cputime_t *newval, cputime_t *oldval) { - union cpu_time_count now; + unsigned long long now; BUG_ON(clock_idx == CPUCLOCK_SCHED); cpu_timer_sample_group(clock_idx, tsk, &now); @@ -1385,18 +1283,18 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, * it to be relative, *newval argument is relative and we update * it to be absolute. */ - if (!cputime_eq(*oldval, cputime_zero)) { - if (cputime_le(*oldval, now.cpu)) { + if (*oldval) { + if (*oldval <= now) { /* Just about to fire. */ *oldval = cputime_one_jiffy; } else { - *oldval = cputime_sub(*oldval, now.cpu); + *oldval -= now; } } - if (cputime_eq(*newval, cputime_zero)) - return; - *newval = cputime_add(*newval, now.cpu); + if (!*newval) + goto out; + *newval += now; } /* @@ -1413,6 +1311,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, tsk->signal->cputime_expires.virt_exp = *newval; break; } +out: + posix_cpu_timer_kick_nohz(); } static int do_cpu_nanosleep(const clockid_t which_clock, int flags, @@ -1444,10 +1344,12 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, } while (!signal_pending(current)) { - if (timer.it.cpu.expires.sched == 0) { + if (timer.it.cpu.expires == 0) { /* - * Our timer fired and was reset. + * Our timer fired and was reset, below + * deletion can not fail. */ + posix_cpu_timer_del(&timer); spin_unlock_irq(&timer.it_lock); return 0; } @@ -1465,9 +1367,26 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, * We were interrupted by a signal. */ sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); - posix_cpu_timer_set(&timer, 0, &zero_it, it); + error = posix_cpu_timer_set(&timer, 0, &zero_it, it); + if (!error) { + /* + * Timer is now unarmed, deletion can not fail. + */ + posix_cpu_timer_del(&timer); + } spin_unlock_irq(&timer.it_lock); + while (error == TIMER_RETRY) { + /* + * We need to handle case when timer was or is in the + * middle of firing. In other cases we already freed + * resources. + */ + spin_lock_irq(&timer.it_lock); + error = posix_cpu_timer_del(&timer); + spin_unlock_irq(&timer.it_lock); + } + if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { /* * It actually did fire already. @@ -1481,11 +1400,13 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, return error; } -int posix_cpu_nsleep(const clockid_t which_clock, int flags, - struct timespec *rqtp, struct timespec __user *rmtp) +static long posix_cpu_nsleep_restart(struct restart_block *restart_block); + +static int posix_cpu_nsleep(const clockid_t which_clock, int flags, + struct timespec *rqtp, struct timespec __user *rmtp) { struct restart_block *restart_block = - ¤t_thread_info()->restart_block; + ¤t_thread_info()->restart_block; struct itimerspec it; int error; @@ -1501,56 +1422,47 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, if (error == -ERESTART_RESTARTBLOCK) { - if (flags & TIMER_ABSTIME) + if (flags & TIMER_ABSTIME) return -ERESTARTNOHAND; /* - * Report back to the user the time still remaining. - */ - if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) + * Report back to the user the time still remaining. + */ + if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) return -EFAULT; restart_block->fn = posix_cpu_nsleep_restart; - restart_block->arg0 = which_clock; - restart_block->arg1 = (unsigned long) rmtp; - restart_block->arg2 = rqtp->tv_sec; - restart_block->arg3 = rqtp->tv_nsec; + restart_block->nanosleep.clockid = which_clock; + restart_block->nanosleep.rmtp = rmtp; + restart_block->nanosleep.expires = timespec_to_ns(rqtp); } return error; } -long posix_cpu_nsleep_restart(struct restart_block *restart_block) +static long posix_cpu_nsleep_restart(struct restart_block *restart_block) { - clockid_t which_clock = restart_block->arg0; - struct timespec __user *rmtp; + clockid_t which_clock = restart_block->nanosleep.clockid; struct timespec t; struct itimerspec it; int error; - rmtp = (struct timespec __user *) restart_block->arg1; - t.tv_sec = restart_block->arg2; - t.tv_nsec = restart_block->arg3; + t = ns_to_timespec(restart_block->nanosleep.expires); - restart_block->fn = do_no_restart_syscall; error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); if (error == -ERESTART_RESTARTBLOCK) { + struct timespec __user *rmtp = restart_block->nanosleep.rmtp; /* - * Report back to the user the time still remaining. - */ - if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) + * Report back to the user the time still remaining. + */ + if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) return -EFAULT; - restart_block->fn = posix_cpu_nsleep_restart; - restart_block->arg0 = which_clock; - restart_block->arg1 = (unsigned long) rmtp; - restart_block->arg2 = t.tv_sec; - restart_block->arg3 = t.tv_nsec; + restart_block->nanosleep.expires = timespec_to_ns(&t); } return error; } - #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) @@ -1594,38 +1506,37 @@ static int thread_cpu_timer_create(struct k_itimer *timer) timer->it_clock = THREAD_CLOCK; return posix_cpu_timer_create(timer); } -static int thread_cpu_nsleep(const clockid_t which_clock, int flags, - struct timespec *rqtp, struct timespec __user *rmtp) -{ - return -EINVAL; -} -static long thread_cpu_nsleep_restart(struct restart_block *restart_block) -{ - return -EINVAL; -} + +struct k_clock clock_posix_cpu = { + .clock_getres = posix_cpu_clock_getres, + .clock_set = posix_cpu_clock_set, + .clock_get = posix_cpu_clock_get, + .timer_create = posix_cpu_timer_create, + .nsleep = posix_cpu_nsleep, + .nsleep_restart = posix_cpu_nsleep_restart, + .timer_set = posix_cpu_timer_set, + .timer_del = posix_cpu_timer_del, + .timer_get = posix_cpu_timer_get, +}; static __init int init_posix_cpu_timers(void) { struct k_clock process = { - .clock_getres = process_cpu_clock_getres, - .clock_get = process_cpu_clock_get, - .clock_set = do_posix_clock_nosettime, - .timer_create = process_cpu_timer_create, - .nsleep = process_cpu_nsleep, - .nsleep_restart = process_cpu_nsleep_restart, + .clock_getres = process_cpu_clock_getres, + .clock_get = process_cpu_clock_get, + .timer_create = process_cpu_timer_create, + .nsleep = process_cpu_nsleep, + .nsleep_restart = process_cpu_nsleep_restart, }; struct k_clock thread = { - .clock_getres = thread_cpu_clock_getres, - .clock_get = thread_cpu_clock_get, - .clock_set = do_posix_clock_nosettime, - .timer_create = thread_cpu_timer_create, - .nsleep = thread_cpu_nsleep, - .nsleep_restart = thread_cpu_nsleep_restart, + .clock_getres = thread_cpu_clock_getres, + .clock_get = thread_cpu_clock_get, + .timer_create = thread_cpu_timer_create, }; struct timespec ts; - register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); - register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); + posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process); + posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread); cputime_to_timespec(cputime_one_jiffy, &ts); onecputick = ts.tv_nsec; |