[tip:timers/core] posix-timers: Make use of cancel/arm callbacks

tip-bot for Thomas Gleixner
2017-06-05T08:26:27Z

Commit-ID: eae1c4ae275fe3e024454c012a548ee0d700f54c
Gitweb: http://git.kernel.org/tip/eae1c4ae275fe3e024454c012a548ee0d700f54c
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 30 May 2017 23:15:53 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 4 Jun 2017 15:40:29 +0200

posix-timers: Make use of cancel/arm callbacks

Replace the hrtimer calls by calls to the new try_to_cancel()/arm() 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/20170530211657.355396667@linutronix.de

---
kernel/time/posix-timers.c | 181 +++++++++++++++++++++++++--------------------
1 file changed, 100 insertions(+), 81 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 0332f7a..8acc9ee 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -744,25 +744,49 @@ SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
return overrun;
}

+static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
+ bool absolute, bool sigev_none)
+{
+ struct hrtimer *timer = &timr->it.real.timer;
+ enum hrtimer_mode mode;
+
+ mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
+ hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
+ timr->it.real.timer.function = posix_timer_fn;
+
+ if (!absolute)
+ expires = ktime_add_safe(expires, timer->base->get_time());
+ hrtimer_set_expires(timer, expires);
+
+ if (!sigev_none)
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
+}
+
+static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
+{
+ return hrtimer_try_to_cancel(&timr->it.real.timer);
+}
+
/* Set a POSIX.1b interval timer. */
-/* timr->it_lock is taken. */
static int
common_timer_set(struct k_itimer *timr, int flags,
- struct itimerspec64 *new_setting, struct itimerspec64 *old_setting)
+ struct itimerspec64 *new_setting,
+ struct itimerspec64 *old_setting)
{
- struct hrtimer *timer = &timr->it.real.timer;
- enum hrtimer_mode mode;
+ const struct k_clock *kc = timr->kclock;
+ bool sigev_none;
+ ktime_t expires;

if (old_setting)
common_timer_get(timr, old_setting);

- /* disable the timer */
+ /* Prevent rearming by clearing the interval */
timr->it_interval = 0;
/*
- * careful here. If smp we could be in the "fire" routine which will
- * be spinning as we hold the lock. But this is ONLY an SMP issue.
+ * Careful here. On SMP systems the timer expiry function could be
+ * active and spinning on timr->it_lock.
*/
- if (hrtimer_try_to_cancel(timer) < 0)
+ if (kc->timer_try_to_cancel(timr) < 0)
return TIMER_RETRY;

timr->it_active = 0;
@@ -770,30 +794,16 @@ common_timer_set(struct k_itimer *timr, int flags,
~REQUEUE_PENDING;
timr->it_overrun_last = 0;

- /* switch off the timer when it_value is zero */
+ /* Switch off the timer when it_value is zero */
if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
return 0;

- mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
- hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
- timr->it.real.timer.function = posix_timer_fn;
-
- hrtimer_set_expires(timer, timespec64_to_ktime(new_setting->it_value));
-
- /* Convert interval */
timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
+ expires = timespec64_to_ktime(new_setting->it_value);
+ sigev_none = (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE;

- /* SIGEV_NONE timers are not queued ! See common_timer_get */
- if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
- /* Setup correct expiry time for relative timers */
- if (mode == HRTIMER_MODE_REL) {
- hrtimer_add_expires(timer, timer->base->get_time());
- }
- return 0;
- }
-
- timr->it_active = 1;
- hrtimer_start_expires(timer, mode);
+ kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
+ timr->it_active = !sigev_none;
return 0;
}

@@ -847,9 +857,10 @@ retry:

static int common_timer_del(struct k_itimer *timer)
{
- timer->it_interval = 0;
+ const struct k_clock *kc = timer->kclock;

- if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
+ timer->it_interval = 0;
+ if (kc->timer_try_to_cancel(timer) < 0)
return TIMER_RETRY;
timer->it_active = 0;
return 0;
@@ -1063,76 +1074,84 @@ long clock_nanosleep_restart(struct restart_block *restart_block)
}

static const struct k_clock clock_realtime = {
- .clock_getres = posix_get_hrtimer_res,
- .clock_get = posix_clock_realtime_get,
- .clock_set = posix_clock_realtime_set,
- .clock_adj = posix_clock_realtime_adj,
- .nsleep = common_nsleep,
- .nsleep_restart = hrtimer_nanosleep_restart,
- .timer_create = common_timer_create,
- .timer_set = common_timer_set,
- .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,
+ .clock_getres = posix_get_hrtimer_res,
+ .clock_get = posix_clock_realtime_get,
+ .clock_set = posix_clock_realtime_set,
+ .clock_adj = posix_clock_realtime_adj,
+ .nsleep = common_nsleep,
+ .nsleep_restart = hrtimer_nanosleep_restart,
+ .timer_create = common_timer_create,
+ .timer_set = common_timer_set,
+ .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,
+ .timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_arm = common_hrtimer_arm,
};

static const struct k_clock clock_monotonic = {
- .clock_getres = posix_get_hrtimer_res,
- .clock_get = posix_ktime_get_ts,
- .nsleep = common_nsleep,
- .nsleep_restart = hrtimer_nanosleep_restart,
- .timer_create = common_timer_create,
- .timer_set = common_timer_set,
- .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,
+ .clock_getres = posix_get_hrtimer_res,
+ .clock_get = posix_ktime_get_ts,
+ .nsleep = common_nsleep,
+ .nsleep_restart = hrtimer_nanosleep_restart,
+ .timer_create = common_timer_create,
+ .timer_set = common_timer_set,
+ .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,
+ .timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_arm = common_hrtimer_arm,
};

static const struct k_clock clock_monotonic_raw = {
- .clock_getres = posix_get_hrtimer_res,
- .clock_get = posix_get_monotonic_raw,
+ .clock_getres = posix_get_hrtimer_res,
+ .clock_get = posix_get_monotonic_raw,
};

static const struct k_clock clock_realtime_coarse = {
- .clock_getres = posix_get_coarse_res,
- .clock_get = posix_get_realtime_coarse,
+ .clock_getres = posix_get_coarse_res,
+ .clock_get = posix_get_realtime_coarse,
};

static const struct k_clock clock_monotonic_coarse = {
- .clock_getres = posix_get_coarse_res,
- .clock_get = posix_get_monotonic_coarse,
+ .clock_getres = posix_get_coarse_res,
+ .clock_get = posix_get_monotonic_coarse,
};

static const struct k_clock clock_tai = {
- .clock_getres = posix_get_hrtimer_res,
- .clock_get = posix_get_tai,
- .nsleep = common_nsleep,
- .nsleep_restart = hrtimer_nanosleep_restart,
- .timer_create = common_timer_create,
- .timer_set = common_timer_set,
- .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,
+ .clock_getres = posix_get_hrtimer_res,
+ .clock_get = posix_get_tai,
+ .nsleep = common_nsleep,
+ .nsleep_restart = hrtimer_nanosleep_restart,
+ .timer_create = common_timer_create,
+ .timer_set = common_timer_set,
+ .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,
+ .timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_arm = common_hrtimer_arm,
};

static const struct k_clock clock_boottime = {
- .clock_getres = posix_get_hrtimer_res,
- .clock_get = posix_get_boottime,
- .nsleep = common_nsleep,
- .nsleep_restart = hrtimer_nanosleep_restart,
- .timer_create = common_timer_create,
- .timer_set = common_timer_set,
- .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,
+ .clock_getres = posix_get_hrtimer_res,
+ .clock_get = posix_get_boottime,
+ .nsleep = common_nsleep,
+ .nsleep_restart = hrtimer_nanosleep_restart,
+ .timer_create = common_timer_create,
+ .timer_set = common_timer_set,
+ .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,
+ .timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_arm = common_hrtimer_arm,
};

static const struct k_clock * const posix_clocks[] = {