From c54bc0fc84214b203f7a0ebfd1bd308ce2abe920 Mon Sep 17 00:00:00 2001
From: Anna-Maria Behnsen <anna-maria@linutronix.de>
Date: Tue, 5 Apr 2022 21:17:32 +0200
Subject: [PATCH] timers: Fix warning condition in __run_timers()
Git-commit: c54bc0fc84214b203f7a0ebfd1bd308ce2abe920
Patch-mainline: v5.18-rc3
References: git-fixes
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
Signed-off-by: Frederic Weisbecker <fweisbecker@suse.com>
---
kernel/time/timer.c | 11 +++++++----
1 file 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);
--
2.25.1