The following commit has been merged into the timers/core branch of tip: Commit-ID: 66f7b0c8aadd2785fc29f2c71477ebc16f4e38cc Gitweb: https://git.kernel.org/tip/66f7b0c8aadd2785fc29f2c71477ebc16f4e38cc Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Tue, 13 Jul 2021 15:39:50 +02:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Tue, 10 Aug 2021 17:57:22 +02:00 timerfd: Provide timerfd_resume() 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. Provide a seperate timerfd_resume() interface so the resume logic and the clock-was-set mechanism can be distangled in the core code. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210713135158.395287410@xxxxxxxxxxxxx --- fs/timerfd.c | 16 ++++++++++++++++ include/linux/hrtimer.h | 2 ++ 2 files changed, 18 insertions(+) diff --git a/fs/timerfd.c b/fs/timerfd.c index c5509d2..e9c96a0 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -115,6 +115,22 @@ void timerfd_clock_was_set(void) rcu_read_unlock(); } +static void timerfd_resume_work(struct work_struct *work) +{ + timerfd_clock_was_set(); +} + +static DECLARE_WORK(timerfd_work, timerfd_resume_work); + +/* + * Invoked from timekeeping_resume(). Defer the actual update to work so + * timerfd_clock_was_set() runs in task context. + */ +void timerfd_resume(void) +{ + schedule_work(&timerfd_work); +} + static void __timerfd_remove_cancel(struct timerfd_ctx *ctx) { if (ctx->might_cancel) { diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 77295af..253c6e2 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -349,8 +349,10 @@ hrtimer_expires_remaining_adjusted(const struct hrtimer *timer) #ifdef CONFIG_TIMERFD extern void timerfd_clock_was_set(void); +extern void timerfd_resume(void); #else static inline void timerfd_clock_was_set(void) { } +static inline void timerfd_resume(void) { } #endif extern void hrtimers_resume(void);
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