From: Frederic Weisbecker <frederic@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>,
Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>
Subject: [PATCH 08/12] timer: Reuse next expiry cache after nohz exit
Date: Fri, 17 Jul 2020 16:05:47 +0200 [thread overview]
Message-ID: <20200717140551.29076-9-frederic@kernel.org> (raw)
In-Reply-To: <20200717140551.29076-1-frederic@kernel.org>
Now that we track the next expiry unconditionally when a timer is added,
we can reuse that information on a tick firing after exiting nohz.
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Juri Lelli <juri.lelli@redhat.com>
---
kernel/time/timer.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 76fd9644638b..13f48ee708aa 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1706,13 +1706,11 @@ static int collect_expired_timers(struct timer_base *base,
* the next expiring timer.
*/
if ((long)(now - base->clk) > 2) {
- unsigned long next = __next_timer_interrupt(base);
-
/*
* If the next timer is ahead of time forward to current
* jiffies, otherwise forward to the next expiry time:
*/
- if (time_after(next, now)) {
+ if (time_after(base->next_expiry, now)) {
/*
* The call site will increment base->clk and then
* terminate the expiry loop immediately.
@@ -1720,7 +1718,7 @@ static int collect_expired_timers(struct timer_base *base,
base->clk = now;
return 0;
}
- base->clk = next;
+ base->clk = base->next_expiry;
}
return __collect_expired_timers(base, heads);
}
--
2.26.2
next prev parent reply other threads:[~2020-07-17 14:06 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 14:05 [PATCH 00/11] timer: Reduce timers softirq v3 Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 01/12] timer: Fix wheel index calculation on last level Frederic Weisbecker
2020-07-17 19:49 ` [tip: timers/urgent] " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 02/12] timer: Preserve higher bits of expiration on index calculation Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 03/12] timers: Use only bucket expiry for base->next_expiry value Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] " tip-bot2 for Anna-Maria Behnsen
2020-07-17 14:05 ` [PATCH 04/12] timer: Move trigger_dyntick_cpu() to enqueue_timer() Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 05/12] timer: Add comments about calc_index() ceiling work Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 06/12] timer: Optimize _next_timer_interrupt() level iteration Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 07/12] timers: Always keep track of next expiry Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` Frederic Weisbecker [this message]
2020-07-17 20:00 ` [tip: timers/core] timers: Reuse next expiry cache after nohz exit tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 09/12] timer: Expand clk forward logic beyond nohz Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 10/12] timer: Spare timer softirq until next expiry Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 11/12] timer: Remove must_forward_clk Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
2020-07-17 14:05 ` [PATCH 12/12] timer: Lower base clock forwarding threshold Frederic Weisbecker
2020-07-17 20:00 ` [tip: timers/core] timers: " tip-bot2 for Frederic Weisbecker
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