From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Peter Xu <peterx@redhat.com>,
Nitesh Narayan Lal <nitesh@redhat.com>,
Alex Belits <abelits@marvell.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
John Stultz <john.stultz@linaro.org>
Subject: [patch 3/8] timerfd: Provide timerfd_resume()
Date: Tue, 27 Apr 2021 10:25:40 +0200 [thread overview]
Message-ID: <20210427083724.318914987@linutronix.de> (raw)
In-Reply-To: 20210427082537.611978720@linutronix.de
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@linutronix.de>
---
fs/timerfd.c | 16 ++++++++++++++++
include/linux/hrtimer.h | 2 ++
2 files changed, 18 insertions(+)
--- 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) {
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -349,8 +349,10 @@ hrtimer_expires_remaining_adjusted(const
#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);
next prev parent reply other threads:[~2021-04-27 8:38 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-27 8:25 [patch 0/8] hrtimers: Overhaul the clock_was_set() logic Thomas Gleixner
2021-04-27 8:25 ` [patch 1/8] hrtimer: Ensure timerfd notification for HIGHRES=n Thomas Gleixner
2021-04-27 8:25 ` [patch 2/8] hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case Thomas Gleixner
2021-05-12 14:59 ` Peter Zijlstra
2021-05-12 16:40 ` Thomas Gleixner
2021-04-27 8:25 ` Thomas Gleixner [this message]
2021-04-27 8:25 ` [patch 4/8] timekeeping: Distangle resume and clock-was-set events Thomas Gleixner
2021-04-27 8:25 ` [patch 5/8] time/timekeeping: Avoid invoking clock_was_set() twice Thomas Gleixner
2021-04-27 8:25 ` [patch 6/8] hrtimer: Add bases argument to clock_was_set() Thomas Gleixner
2021-04-27 8:25 ` [patch 7/8] hrtimer: Avoid unnecessary SMP function calls in clock_was_set() Thomas Gleixner
2021-05-13 14:59 ` Peter Zijlstra
2021-05-14 18:52 ` Thomas Gleixner
2021-05-14 23:28 ` Peter Zijlstra
2021-05-15 0:24 ` Thomas Gleixner
2021-04-27 8:25 ` [patch 8/8] hrtimer: Avoid more " Thomas Gleixner
2021-04-27 15:11 ` Marcelo Tosatti
2021-04-27 19:59 ` Thomas Gleixner
2021-04-30 7:12 ` [patch V2 " Thomas Gleixner
2021-04-30 16:49 ` Marcelo Tosatti
2021-05-13 7:47 ` Peter Zijlstra
2021-05-14 19:08 ` Thomas Gleixner
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