X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fhrtimer.c;h=859640952b001c9120c142b322cb237b83fea95a;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=14bc9cfa63999eee7fa1b25e4129ee67463e53bc;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 14bc9cfa6..859640952 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -98,7 +98,6 @@ static DEFINE_PER_CPU(struct hrtimer_base, hrtimer_bases[MAX_HRTIMER_BASES]) = /** * ktime_get_ts - get the monotonic clock in timespec format - * * @ts: pointer to timespec variable * * The function calculates the monotonic clock from the realtime @@ -122,6 +121,26 @@ void ktime_get_ts(struct timespec *ts) } EXPORT_SYMBOL_GPL(ktime_get_ts); +/* + * Get the coarse grained time at the softirq based on xtime and + * wall_to_monotonic. + */ +static void hrtimer_get_softirq_time(struct hrtimer_base *base) +{ + ktime_t xtim, tomono; + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + xtim = timespec_to_ktime(xtime); + tomono = timespec_to_ktime(wall_to_monotonic); + + } while (read_seqretry(&xtime_lock, seq)); + + base[CLOCK_REALTIME].softirq_time = xtim; + base[CLOCK_MONOTONIC].softirq_time = ktime_add(xtim, tomono); +} + /* * Functions and macros which are different for UP/SMP systems are kept in a * single place @@ -168,7 +187,7 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base) { struct hrtimer_base *new_base; - new_base = &__get_cpu_var(hrtimer_bases[base->index]); + new_base = &__get_cpu_var(hrtimer_bases)[base->index]; if (base != new_base) { /* @@ -218,7 +237,6 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) # ifndef CONFIG_KTIME_SCALAR /** * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable - * * @kt: addend * @nsec: the scalar nsec value to add * @@ -246,7 +264,7 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) /* * Divide a ktime value by a nanosecond value */ -static unsigned long ktime_divns(const ktime_t kt, nsec_t div) +static unsigned long ktime_divns(const ktime_t kt, s64 div) { u64 dclc, inc, dns; int sft = 0; @@ -279,20 +297,18 @@ void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) /** * hrtimer_forward - forward the timer expiry - * * @timer: hrtimer to forward + * @now: forward past this time * @interval: the interval to forward * * Forward the timer expiry so it will expire in the future. * Returns the number of overruns. */ unsigned long -hrtimer_forward(struct hrtimer *timer, ktime_t interval) +hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) { unsigned long orun = 1; - ktime_t delta, now; - - now = timer->base->get_time(); + ktime_t delta; delta = ktime_sub(now, timer->expires); @@ -303,7 +319,7 @@ hrtimer_forward(struct hrtimer *timer, ktime_t interval) interval.tv64 = timer->base->resolution.tv64; if (unlikely(delta.tv64 >= interval.tv64)) { - nsec_t incr = ktime_to_ns(interval); + s64 incr = ktime_to_ns(interval); orun = ktime_divns(delta, incr); timer->expires = ktime_add_ns(timer->expires, incr * orun); @@ -316,6 +332,12 @@ hrtimer_forward(struct hrtimer *timer, ktime_t interval) orun++; } timer->expires = ktime_add(timer->expires, interval); + /* + * Make sure, that the result did not wrap with a very large + * interval. + */ + if (timer->expires.tv64 < 0) + timer->expires = ktime_set(KTIME_SEC_MAX, 0); return orun; } @@ -355,8 +377,6 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) rb_link_node(&timer->node, parent, link); rb_insert_color(&timer->node, &base->active); - timer->state = HRTIMER_PENDING; - if (!base->first || timer->expires.tv64 < rb_entry(base->first, struct hrtimer, node)->expires.tv64) base->first = &timer->node; @@ -376,6 +396,7 @@ static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) if (base->first == &timer->node) base->first = rb_next(&timer->node); rb_erase(&timer->node, &base->active); + rb_set_parent(&timer->node, &timer->node); } /* @@ -386,7 +407,6 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) { if (hrtimer_active(timer)) { __remove_hrtimer(timer, base); - timer->state = HRTIMER_INACTIVE; return 1; } return 0; @@ -394,7 +414,6 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) /** * hrtimer_start - (re)start an relative timer on the current CPU - * * @timer: the timer to be added * @tim: expiry time * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) @@ -439,17 +458,17 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) return ret; } +EXPORT_SYMBOL_GPL(hrtimer_start); /** * hrtimer_try_to_cancel - try to deactivate a timer - * * @timer: hrtimer to stop * * Returns: * 0 when the timer was not active * 1 when the timer was active * -1 when the timer is currently excuting the callback function and - * can not be stopped + * cannot be stopped */ int hrtimer_try_to_cancel(struct hrtimer *timer) { @@ -467,10 +486,10 @@ int hrtimer_try_to_cancel(struct hrtimer *timer) return ret; } +EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); /** * hrtimer_cancel - cancel a timer and wait for the handler to finish. - * * @timer: the timer to be cancelled * * Returns: @@ -484,12 +503,13 @@ int hrtimer_cancel(struct hrtimer *timer) if (ret >= 0) return ret; + cpu_relax(); } } +EXPORT_SYMBOL_GPL(hrtimer_cancel); /** * hrtimer_get_remaining - get remaining time for the timer - * * @timer: the timer to read */ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) @@ -504,6 +524,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) return rem; } +EXPORT_SYMBOL_GPL(hrtimer_get_remaining); #ifdef CONFIG_NO_IDLE_HZ /** @@ -542,7 +563,6 @@ ktime_t hrtimer_get_next_event(void) /** * hrtimer_init - initialize a timer to the given clock - * * @timer: the timer to be initialized * @clock_id: the clock to be used * @mode: timer mode abs/rel @@ -554,17 +574,18 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, memset(timer, 0, sizeof(struct hrtimer)); - bases = per_cpu(hrtimer_bases, raw_smp_processor_id()); + bases = __raw_get_cpu_var(hrtimer_bases); if (clock_id == CLOCK_REALTIME && mode != HRTIMER_ABS) clock_id = CLOCK_MONOTONIC; timer->base = &bases[clock_id]; + rb_set_parent(&timer->node, &timer->node); } +EXPORT_SYMBOL_GPL(hrtimer_init); /** * hrtimer_get_res - get the timer resolution for a clock - * * @which_clock: which clock to query * @tp: pointer to timespec variable to store the resolution * @@ -575,59 +596,50 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) { struct hrtimer_base *bases; - bases = per_cpu(hrtimer_bases, raw_smp_processor_id()); + bases = __raw_get_cpu_var(hrtimer_bases); *tp = ktime_to_timespec(bases[which_clock].resolution); return 0; } +EXPORT_SYMBOL_GPL(hrtimer_get_res); /* * Expire the per base hrtimer-queue: */ static inline void run_hrtimer_queue(struct hrtimer_base *base) { - ktime_t now = base->get_time(); struct rb_node *node; + if (!base->first) + return; + + if (base->get_softirq_time) + base->softirq_time = base->get_softirq_time(); + spin_lock_irq(&base->lock); while ((node = base->first)) { struct hrtimer *timer; - int (*fn)(void *); + int (*fn)(struct hrtimer *); int restart; - void *data; timer = rb_entry(node, struct hrtimer, node); - if (now.tv64 <= timer->expires.tv64) + if (base->softirq_time.tv64 <= timer->expires.tv64) break; fn = timer->function; - data = timer->data; set_curr_timer(base, timer); - timer->state = HRTIMER_RUNNING; __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(timer); spin_lock_irq(&base->lock); - /* Another CPU has added back the timer */ - if (timer->state != HRTIMER_RUNNING) - continue; - - if (restart == HRTIMER_RESTART) + if (restart != HRTIMER_NORESTART) { + BUG_ON(hrtimer_active(timer)); enqueue_hrtimer(timer, base); - else - timer->state = HRTIMER_EXPIRED; + } } set_curr_timer(base, NULL); spin_unlock_irq(&base->lock); @@ -641,6 +653,8 @@ void hrtimer_run_queues(void) struct hrtimer_base *base = __get_cpu_var(hrtimer_bases); int i; + hrtimer_get_softirq_time(base); + for (i = 0; i < MAX_HRTIMER_BASES; i++) run_hrtimer_queue(&base[i]); } @@ -648,80 +662,69 @@ 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) +static int hrtimer_wakeup(struct hrtimer *timer) { - /* fn stays NULL, meaning single-shot wakeup: */ - timer->data = current; + struct hrtimer_sleeper *t = + container_of(timer, struct hrtimer_sleeper, timer); + struct task_struct *task = t->task; - hrtimer_start(timer, timer->expires, mode); + t->task = NULL; + if (task) + wake_up_process(task); - schedule(); - hrtimer_cancel(timer); + return HRTIMER_NORESTART; +} - /* Return the remaining time: */ - if (timer->state != HRTIMER_EXPIRED) - return ktime_sub(timer->expires, timer->base->get_time()); - else - return (ktime_t) {.tv64 = 0 }; +void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) +{ + sl->timer.function = hrtimer_wakeup; + sl->task = task; } -static inline ktime_t __sched -schedule_hrtimer_interruptible(struct hrtimer *timer, - const enum hrtimer_mode mode) +static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) { - set_current_state(TASK_INTERRUPTIBLE); + hrtimer_init_sleeper(t, current); + + do { + set_current_state(TASK_INTERRUPTIBLE); + hrtimer_start(&t->timer, t->timer.expires, mode); - return schedule_hrtimer(timer, mode); + schedule(); + + hrtimer_cancel(&t->timer); + mode = HRTIMER_ABS; + + } while (t->task && !signal_pending(current)); + + return t->task == NULL; } -static long __sched nanosleep_restart(struct restart_block *restart) +long __sched hrtimer_nanosleep_restart(struct restart_block *restart) { + struct hrtimer_sleeper 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); + hrtimer_init(&t.timer, restart->arg0, HRTIMER_ABS); + t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2; - 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; + rmtp = (struct timespec __user *) restart->arg1; + 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 = hrtimer_nanosleep_restart; /* The other values in restart are already filled in */ return -ERESTART_RESTARTBLOCK; @@ -731,33 +734,34 @@ 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 hrtimer_sleeper 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->arg2 = (unsigned long) rmtp; - restart->arg3 = (unsigned long) timer.base->index; + restart->fn = hrtimer_nanosleep_restart; + restart->arg0 = (unsigned long) t.timer.base->index; + restart->arg1 = (unsigned long) rmtp; + restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF; + restart->arg3 = t.timer.expires.tv64 >> 32; return -ERESTART_RESTARTBLOCK; } @@ -784,8 +788,10 @@ static void __devinit init_hrtimers_cpu(int cpu) struct hrtimer_base *base = per_cpu(hrtimer_bases, cpu); int i; - for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) + for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) { spin_lock_init(&base->lock); + lockdep_set_class(&base->lock, &base->lock_key); + } } #ifdef CONFIG_HOTPLUG_CPU @@ -835,7 +841,7 @@ static void migrate_hrtimers(int cpu) } #endif /* CONFIG_HOTPLUG_CPU */ -static int __devinit hrtimer_cpu_notify(struct notifier_block *self, +static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { long cpu = (long)hcpu; @@ -859,7 +865,7 @@ static int __devinit hrtimer_cpu_notify(struct notifier_block *self, return NOTIFY_OK; } -static struct notifier_block __devinitdata hrtimers_nb = { +static struct notifier_block __cpuinitdata hrtimers_nb = { .notifier_call = hrtimer_cpu_notify, };