summary refs log tree commit diff
path: root/kernel
diff options
context:
space:
mode:
authorAnna-Maria Behnsen <anna-maria@linutronix.de>2022-04-05 21:17:32 +0200
committerThomas Gleixner <tglx@linutronix.de>2022-04-09 22:17:47 +0200
commitc54bc0fc84214b203f7a0ebfd1bd308ce2abe920 (patch)
tree073c27dcaaa24d211de3c0061d39d3f3e854fce5 /kernel
parent3123109284176b1532874591f7c81f3837bbdc17 (diff)
downloadlinux-c54bc0fc84214b203f7a0ebfd1bd308ce2abe920.tar.gz
timers: Fix warning condition in __run_timers()
When the timer base is empty, base::next_expiry is set to base::clk +
NEXT_TIMER_MAX_DELTA and base::next_expiry_recalc is false. When no timer
is queued until jiffies reaches base::next_expiry value, the warning for
not finding any expired timer and base::next_expiry_recalc is false in
__run_timers() triggers.

To prevent triggering the warning in this valid scenario
base::timers_pending needs to be added to the warning condition.

Fixes: 31cd0e119d50 ("timers: Recalculate next timer interrupt only when necessary")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
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/20220405191732.7438-3-anna-maria@linutronix.de

Diffstat (limited to 'kernel')
-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 85f1021ad459..9dd2a39cb3b0 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1722,11 +1722,14 @@ static inline void __run_timers(struct timer_base *base)
 	       time_after_eq(jiffies, base->next_expiry)) {
 		levels = collect_expired_timers(base, heads);
 		/*
-		 * The only possible reason for not finding any expired
-		 * timer at this clk is that all matching timers have been
-		 * dequeued.
+		 * The two possible reasons for not finding any expired
+		 * timer at this clk are that all matching timers have been
+		 * dequeued or no timer has been queued since
+		 * base::next_expiry was set to base::clk +
+		 * NEXT_TIMER_MAX_DELTA.
 		 */
-		WARN_ON_ONCE(!levels && !base->next_expiry_recalc);
+		WARN_ON_ONCE(!levels && !base->next_expiry_recalc
+			     && base->timers_pending);
 		base->clk++;
 		base->next_expiry = __next_timer_interrupt(base);