[tip:timers/core] posix-timers: Make use of forward/remaining callbacks

tip-bot for Thomas Gleixner
2017-06-05T08:24:46Z

Commit-ID: 91d57bae08689199c8acc77a8b3b41150cafab1c
Gitweb: http://git.kernel.org/tip/91d57bae08689199c8acc77a8b3b41150cafab1c
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 30 May 2017 23:15:50 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 4 Jun 2017 15:40:27 +0200

posix-timers: Make use of forward/remaining callbacks

Replace the hrtimer calls by calls to the new forward/remaining kclock
callbacks and move the hrtimer specific implementation into the
corresponding callback functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.121437232@linutronix.de

---
kernel/time/posix-timers.c | 64 +++++++++++++++++++++++++++++++++++-----------
1 file changed, 49 insertions(+), 15 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 795215b..48f6c37 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -607,6 +607,20 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
return NULL;
}

+static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now)
+{
+ struct hrtimer *timer = &timr->it.real.timer;
+
+ return __hrtimer_expires_remaining_adjusted(timer, now);
+}
+
+static int common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
+{
+ struct hrtimer *timer = &timr->it.real.timer;
+
+ return (int)hrtimer_forward(timer, now, timr->it_interval);
+}
+
/*
* Get the time remaining on a POSIX.1b interval timer. This function
* is ALWAYS called with spin_lock_irq on the timer, thus it must not
@@ -626,42 +640,54 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
static void
common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
{
+ const struct k_clock *kc = timr->kclock;
ktime_t now, remaining, iv;
- struct hrtimer *timer = &timr->it.real.timer;
+ struct timespec64 ts64;
+ bool sig_none;

memset(cur_setting, 0, sizeof(*cur_setting));

+ sig_none = (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE;
iv = timr->it_interval;

/* interval timer ? */
- if (iv)
+ if (iv) {
cur_setting->it_interval = ktime_to_timespec64(iv);
- else if (!hrtimer_active(timer) &&
- (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
- return;
+ } else if (!timr->it_active) {
+ /*
+ * SIGEV_NONE oneshot timers are never queued. Check them
+ * below.
+ */
+ if (!sig_none)
+ return;
+ }

- now = timer->base->get_time();
+ /*
+ * The timespec64 based conversion is suboptimal, but it's not
+ * worth to implement yet another callback.
+ */
+ kc->clock_get(timr->it_clock, &ts64);
+ now = timespec64_to_ktime(ts64);

/*
- * When a requeue is pending or this is a SIGEV_NONE
- * timer move the expiry time forward by intervals, so
- * expiry is > now.
+ * When a requeue is pending or this is a SIGEV_NONE timer move the
+ * expiry time forward by intervals, so expiry is > now.
*/
- if (iv && (timr->it_requeue_pending & REQUEUE_PENDING ||
- (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
- timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
+ if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
+ timr->it_overrun += kc->timer_forward(timr, now);

- remaining = __hrtimer_expires_remaining_adjusted(timer, now);
+ remaining = kc->timer_remaining(timr, now);
/* Return 0 only, when the timer is expired and not pending */
if (remaining <= 0) {
/*
* A single shot SIGEV_NONE timer must return 0, when
* it is expired !
*/
- if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
+ if (!sig_none)
cur_setting->it_value.tv_nsec = 1;
- } else
+ } else {
cur_setting->it_value = ktime_to_timespec64(remaining);
+ }
}

/* Get the time remaining on a POSIX.1b interval timer. */
@@ -1049,6 +1075,8 @@ static const struct k_clock clock_realtime = {
.timer_get = common_timer_get,
.timer_del = common_timer_del,
.timer_rearm = common_hrtimer_rearm,
+ .timer_forward = common_hrtimer_forward,
+ .timer_remaining= common_hrtimer_remaining,
};

static const struct k_clock clock_monotonic = {
@@ -1061,6 +1089,8 @@ static const struct k_clock clock_monotonic = {
.timer_get = common_timer_get,
.timer_del = common_timer_del,
.timer_rearm = common_hrtimer_rearm,
+ .timer_forward = common_hrtimer_forward,
+ .timer_remaining= common_hrtimer_remaining,
};

static const struct k_clock clock_monotonic_raw = {
@@ -1088,6 +1118,8 @@ static const struct k_clock clock_tai = {
.timer_get = common_timer_get,
.timer_del = common_timer_del,
.timer_rearm = common_hrtimer_rearm,
+ .timer_forward = common_hrtimer_forward,
+ .timer_remaining= common_hrtimer_remaining,
};

static const struct k_clock clock_boottime = {
@@ -1100,6 +1132,8 @@ static const struct k_clock clock_boottime = {
.timer_get = common_timer_get,
.timer_del = common_timer_del,
.timer_rearm = common_hrtimer_rearm,
+ .timer_forward = common_hrtimer_forward,
+ .timer_remaining= common_hrtimer_remaining,
};

static const struct k_clock * const posix_clocks[] = {