[PATCH 1/2] timers: Initialize base::next_expiry_recalc during prepare cpu - Anna-Maria Behnsen

From: Anna-Maria Behnsen <anna-maria@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Frederic Weisbecker <frederic@kernel.org>
Subject: [PATCH 1/2] timers: Initialize base::next_expiry_recalc during prepare cpu
Date: Tue,  5 Apr 2022 21:17:31 +0200	[thread overview]
Message-ID: <20220405191732.7438-2-anna-maria@linutronix.de> (raw)
In-Reply-To: <20220405191732.7438-1-anna-maria@linutronix.de>

When base::next_expiry_recalc is not initialized to false during cpu
bringup in HOTPLUG_CPU and is accidently true and no timer is queued in the
meantime, the loop through the wheel to find __next_timer_interrupt() might
be done for nothing.

Therefore initialize base::next_expiry_recalc to false in
timers_prepare_cpu().

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
---
 kernel/time/timer.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 85f1021ad459..4af98e77cd78 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1950,6 +1950,7 @@ int timers_prepare_cpu(unsigned int cpu)
 		base = per_cpu_ptr(&timer_bases[b], cpu);
 		base->clk = jiffies;
 		base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA;
+		base->next_expiry_recalc = false;
 		base->timers_pending = false;
 		base->is_idle = false;
 	}
-- 
2.20.1

