From: Roman Zippel <[email protected]>
nanosleep is the only user of the expired state, so let it manage this
itself, which makes the hrtimer code a bit simpler. The remaining time
is also only calculated if requested.
Signed-off-by: Roman Zippel <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
include/linux/hrtimer.h | 4 -
kernel/hrtimer.c | 142 ++++++++++++++++++++----------------------------
2 files changed, 63 insertions(+), 83 deletions(-)
Index: linux-2.6.16-updates/include/linux/hrtimer.h
===================================================================
--- linux-2.6.16-updates.orig/include/linux/hrtimer.h
+++ linux-2.6.16-updates/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 */
};
Index: linux-2.6.16-updates/kernel/hrtimer.c
===================================================================
--- linux-2.6.16-updates.orig/kernel/hrtimer.c
+++ linux-2.6.16-updates/kernel/hrtimer.c
@@ -625,30 +625,20 @@ static inline void run_hrtimer_queue(str
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);
- return schedule_hrtimer(timer, mode);
+ schedule();
+
+ 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 *
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;
}
--
-
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