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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-07-13 16:39:51 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-08-10 18:57:23 +0300 |
| commit | a761a67f591a8c7476c30bb20ed0f09fdfb1a704 (patch) | |
| tree | b3a19dfca4e52fde11ceb2ba23447130cc3408ee /kernel/time/hrtimer.c | |
| parent | 66f7b0c8aadd2785fc29f2c71477ebc16f4e38cc (diff) | |
| download | linux-a761a67f591a8c7476c30bb20ed0f09fdfb1a704.tar.xz | |
timekeeping: Distangle resume and clock-was-set events
Resuming timekeeping is a clock-was-set event and uses the clock-was-set
notification mechanism. This is in the way of making the clock-was-set
update for hrtimers selective so unnecessary IPIs are avoided when a CPU
base does not have timers queued which are affected by the clock setting.
Distangle it by invoking hrtimer_resume() on each unfreezing CPU and invoke
the new timerfd_resume() function from timekeeping_resume() which is the
only place where this is needed.
Rename hrtimer_resume() to hrtimer_resume_local() to reflect the change.
With this the clock_was_set*() functions are not longer required to IPI all
CPUs unconditionally and can get some smarts to avoid them.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.488853478@linutronix.de
Diffstat (limited to 'kernel/time/hrtimer.c')
| -rw-r--r-- | kernel/time/hrtimer.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 214fd65a9597..68e56f0ecb09 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -900,8 +900,8 @@ static void clock_was_set_work(struct work_struct *work) static DECLARE_WORK(hrtimer_work, clock_was_set_work); /* - * Called from timekeeping and resume code to reprogram the hrtimer - * interrupt device on all cpus and to notify timerfd. + * Called from timekeeping code to reprogram the hrtimer interrupt device + * on all cpus and to notify timerfd. */ void clock_was_set_delayed(void) { @@ -909,18 +909,15 @@ void clock_was_set_delayed(void) } /* - * During resume we might have to reprogram the high resolution timer - * interrupt on all online CPUs. However, all other CPUs will be - * stopped with IRQs interrupts disabled so the clock_was_set() call - * must be deferred. + * Called during resume either directly from via timekeeping_resume() + * or in the case of s2idle from tick_unfreeze() to ensure that the + * hrtimers are up to date. */ -void hrtimers_resume(void) +void hrtimers_resume_local(void) { lockdep_assert_irqs_disabled(); /* Retrigger on the local CPU */ retrigger_next_event(NULL); - /* And schedule a retrigger for all others */ - clock_was_set_delayed(); } /* |