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authorThomas Gleixner <tglx@linutronix.de>2020-12-06 22:12:54 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-12-16 11:26:27 +0100
commitf12ad423c4af877b2e4b5a80928b95195fccab04 (patch)
tree60d3317a1c3d8ec0e094749088acfe0f63665225
parentMerge tag 'timers-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kern... (diff)
downloadlinux-f12ad423c4af877b2e4b5a80928b95195fccab04.tar.xz
linux-f12ad423c4af877b2e4b5a80928b95195fccab04.zip
tick: Remove pointless cpu valid check in hotplug code
tick_handover_do_timer() which is invoked when a CPU is unplugged has a check for cpumask_first(cpu_online_mask) when it tries to hand over the tick update duty. Checking the result of cpumask_first() there is pointless because if the online mask is empty at this point, then this would be the last CPU in the system going offline, which is impossible. There is always at least one CPU remaining. If online mask would be really empty then the timer duty would be the least of the resulting problems. Remove the well meant check simply because it is pointless and confusing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20201206212002.582579516@linutronix.de
-rw-r--r--kernel/time/tick-common.c10
1 files changed, 3 insertions, 7 deletions
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index a03764df5366..9d3a22510bab 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -407,17 +407,13 @@ EXPORT_SYMBOL_GPL(tick_broadcast_oneshot_control);
/*
* Transfer the do_timer job away from a dying cpu.
*
- * Called with interrupts disabled. Not locking required. If
+ * Called with interrupts disabled. No locking required. If
* tick_do_timer_cpu is owned by this cpu, nothing can change it.
*/
void tick_handover_do_timer(void)
{
- if (tick_do_timer_cpu == smp_processor_id()) {
- int cpu = cpumask_first(cpu_online_mask);
-
- tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
- TICK_DO_TIMER_NONE;
- }
+ if (tick_do_timer_cpu == smp_processor_id())
+ tick_do_timer_cpu = cpumask_first(cpu_online_mask);
}
/*