From e7cad586d73276cbd4466de81b2092287d7475c0 Mon Sep 17 00:00:00 2001 From: Liang Hao Date: Wed, 30 Sep 2026 14:36:21 +0800 Subject: [PATCH] timers: Clear pending_map on CPU hotplug CPU hotplug migration leaves pending_map bits set on the outgoing CPU while its wheel vectors are empty. After re-online, a later next_expiry recalc can treat those empty buckets as pending and temporarily pull next_expiry forward until collect drains the bits. Clear pending_map under the base lock after migration in timers_dead_cpu(). Fixes: 500462a9de65 ("timers: Switch to a non-cascading wheel") Signed-off-by: Liang Hao Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/20260930063621.37740-1-haohlliang@gmail.com --- kernel/time/timer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index ae9abf14688e..fc374444acb6 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -44,6 +44,7 @@ #include #include #include +#include #include #include @@ -2541,6 +2542,7 @@ int timers_dead_cpu(unsigned int cpu) for (i = 0; i < WHEEL_SIZE; i++) migrate_timer_list(new_base, old_base->vectors + i); + bitmap_zero(old_base->pending_map, WHEEL_SIZE); raw_spin_unlock(&old_base->lock); raw_spin_unlock_irq(&new_base->lock); put_cpu_ptr(&timer_bases);