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authorAnna-Maria Behnsen <anna-maria@linutronix.de>2023-12-01 10:26:30 +0100
committerThomas Gleixner <tglx@linutronix.de>2023-12-20 16:49:38 +0100
commit8a2c9c7e7848d7f63d38b698209148b5bb4ba7f3 (patch)
tree4a3edc498a7cedf14d7c9f806939274c682f973c
parentb5e6f59888c7bde3c05f61b3ce06b78a86713fc0 (diff)
timers: Clarify check in forward_timer_base()
The current check whether a forward of the timer base is required can be simplified by using an already existing comparison function which is easier to read. The related comment is outdated and was not updated when the check changed in commit 36cd28a4cdd0 ("timers: Lower base clock forwarding threshold"). Use time_before_eq() for the check and replace the comment by copying the comment from the same check inside get_next_timer_interrupt(). Move the precious information of the outdated comment to the proper place in __run_timers(). No functional change. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-9-anna-maria@linutronix.de
-rw-r--r--kernel/time/timer.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 490ff8e66fc2..f75f932b128e 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -944,11 +944,10 @@ static inline void forward_timer_base(struct timer_base *base)
unsigned long jnow = READ_ONCE(jiffies);
/*
- * No need to forward if we are close enough below jiffies.
- * Also while executing timers, base->clk is 1 offset ahead
- * of jiffies to avoid endless requeuing to current jiffies.
+ * Check whether we can forward the base. We can only do that when
+ * @basej is past base->clk otherwise we might rewind base->clk.
*/
- if ((long)(jnow - base->clk) < 1)
+ if (time_before_eq(jnow, base->clk))
return;
/*
@@ -2021,6 +2020,10 @@ static inline void __run_timers(struct timer_base *base)
*/
WARN_ON_ONCE(!levels && !base->next_expiry_recalc
&& base->timers_pending);
+ /*
+ * While executing timers, base->clk is set 1 offset ahead of
+ * jiffies to avoid endless requeuing to current jiffies.
+ */
base->clk++;
next_expiry_recalc(base);