diff options
| -rw-r--r-- | include/linux/hrtimer.h | 4 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 142 |
2 files changed, 63 insertions, 83 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 84fc186324e..0e8f4762f6f 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -38,9 +38,7 @@ enum hrtimer_restart { * Timer states: */ enum hrtimer_state { - HRTIMER_INACTIVE, /* Timer is inactive */ - HRTIMER_EXPIRED, /* Timer is expired */ - HRTIMER_RUNNING, /* Timer is running the callback function */ + HRTIMER_INACTIVE, /* Timer is inactive */ HRTIMER_PENDING, /* Timer is pending */ }; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index e989c9981a9..59ec50c1e90 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -625,30 +625,20 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base) fn = timer->function; data = timer->data; set_curr_timer(base, timer); - timer->state = HRTIMER_RUNNING; + timer->state = HRTIMER_INACTIVE; __remove_hrtimer(timer, base); spin_unlock_irq(&base->lock); - /* - * fn == NULL is special case for the simplest timer - * variant - wake up process and do not restart: - */ - if (!fn) { - wake_up_process(data); - restart = HRTIMER_NORESTART; - } else - restart = fn(data); + restart = fn(data); spin_lock_irq(&base->lock); /* Another CPU has added back the timer */ - if (timer->state != HRTIMER_RUNNING) + if (timer->state != HRTIMER_INACTIVE) continue; - if (restart == HRTIMER_RESTART) + if (restart != HRTIMER_NORESTART) enqueue_hrtimer(timer, base); - else - timer->state = HRTIMER_EXPIRED; } set_curr_timer(base, NULL); spin_unlock_irq(&base->lock); @@ -672,79 +662,70 @@ void hrtimer_run_queues(void) * Sleep related functions: */ -/** - * schedule_hrtimer - sleep until timeout - * - * @timer: hrtimer variable initialized with the correct clock base - * @mode: timeout value is abs/rel - * - * Make the current task sleep until @timeout is - * elapsed. - * - * You can set the task state as follows - - * - * %TASK_UNINTERRUPTIBLE - at least @timeout is guaranteed to - * pass before the routine returns. The routine will return 0 - * - * %TASK_INTERRUPTIBLE - the routine may return early if a signal is - * delivered to the current task. In this case the remaining time - * will be returned - * - * The current task state is guaranteed to be TASK_RUNNING when this - * routine returns. - */ -static ktime_t __sched -schedule_hrtimer(struct hrtimer *timer, const enum hrtimer_mode mode) -{ - /* fn stays NULL, meaning single-shot wakeup: */ - timer->data = current; +struct sleep_hrtimer { + struct hrtimer timer; + struct task_struct *task; + int expired; +}; - hrtimer_start(timer, timer->expires, mode); +static int nanosleep_wakeup(void *data) +{ + struct sleep_hrtimer *t = data; - schedule(); - hrtimer_cancel(timer); + t->expired = 1; + wake_up_process(t->task); - /* Return the remaining time: */ - if (timer->state != HRTIMER_EXPIRED) - return ktime_sub(timer->expires, timer->base->get_time()); - else - return (ktime_t) {.tv64 = 0 }; + return HRTIMER_NORESTART; } -static inline ktime_t __sched -schedule_hrtimer_interruptible(struct hrtimer *timer, - const enum hrtimer_mode mode) +static int __sched do_nanosleep(struct sleep_hrtimer *t, enum hrtimer_mode mode) { - set_current_state(TASK_INTERRUPTIBLE); + t->timer.function = nanosleep_wakeup; + t->timer.data = t; + t->task = current; + t->expired = 0; + + do { + set_current_state(TASK_INTERRUPTIBLE); + hrtimer_start(&t->timer, t->timer.expires, mode); + + schedule(); - return schedule_hrtimer(timer, mode); + if (unlikely(!t->expired)) { + hrtimer_cancel(&t->timer); + mode = HRTIMER_ABS; + } + } while (!t->expired && !signal_pending(current)); + + return t->expired; } static long __sched nanosleep_restart(struct restart_block *restart) { + struct sleep_hrtimer t; struct timespec __user *rmtp; struct timespec tu; - void *rfn_save = restart->fn; - struct hrtimer timer; - ktime_t rem; + ktime_t time; restart->fn = do_no_restart_syscall; - hrtimer_init(&timer, (clockid_t) restart->arg3, HRTIMER_ABS); - - timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0; + hrtimer_init(&t.timer, restart->arg3, HRTIMER_ABS); + t.timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0; - rem = schedule_hrtimer_interruptible(&timer, HRTIMER_ABS); - - if (rem.tv64 <= 0) + if (do_nanosleep(&t, HRTIMER_ABS)) return 0; rmtp = (struct timespec __user *) restart->arg2; - tu = ktime_to_timespec(rem); - if (rmtp && copy_to_user(rmtp, &tu, sizeof(tu))) - return -EFAULT; + if (rmtp) { + time = ktime_sub(t.timer.expires, t.timer.base->get_time()); + if (time.tv64 <= 0) + return 0; + tu = ktime_to_timespec(time); + if (copy_to_user(rmtp, &tu, sizeof(tu))) + return -EFAULT; + } - restart->fn = rfn_save; + restart->fn = nanosleep_restart; /* The other values in restart are already filled in */ return -ERESTART_RESTARTBLOCK; @@ -754,33 +735,34 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, const enum hrtimer_mode mode, const clockid_t clockid) { struct restart_block *restart; - struct hrtimer timer; + struct sleep_hrtimer t; struct timespec tu; ktime_t rem; - hrtimer_init(&timer, clockid, mode); - - timer.expires = timespec_to_ktime(*rqtp); - - rem = schedule_hrtimer_interruptible(&timer, mode); - if (rem.tv64 <= 0) + hrtimer_init(&t.timer, clockid, mode); + t.timer.expires = timespec_to_ktime(*rqtp); + if (do_nanosleep(&t, mode)) return 0; /* Absolute timers do not update the rmtp value and restart: */ if (mode == HRTIMER_ABS) return -ERESTARTNOHAND; - tu = ktime_to_timespec(rem); - - if (rmtp && copy_to_user(rmtp, &tu, sizeof(tu))) - return -EFAULT; + if (rmtp) { + rem = ktime_sub(t.timer.expires, t.timer.base->get_time()); + if (rem.tv64 <= 0) + return 0; + tu = ktime_to_timespec(rem); + if (copy_to_user(rmtp, &tu, sizeof(tu))) + return -EFAULT; + } restart = ¤t_thread_info()->restart_block; restart->fn = nanosleep_restart; - restart->arg0 = timer.expires.tv64 & 0xFFFFFFFF; - restart->arg1 = timer.expires.tv64 >> 32; + restart->arg0 = t.timer.expires.tv64 & 0xFFFFFFFF; + restart->arg1 = t.timer.expires.tv64 >> 32; restart->arg2 = (unsigned long) rmtp; - restart->arg3 = (unsigned long) timer.base->index; + restart->arg3 = (unsigned long) t.timer.base->index; return -ERESTART_RESTARTBLOCK; } |