Re: [PATCH 01/15] sched/idle: Handle offlining first in idle loop
From: Peter Zijlstra <peterz@infradead.org>
Date: 2026-01-19 12:54:10
Also in:
linux-pm, linux-s390, lkml
On Fri, Jan 16, 2026 at 03:51:54PM +0100, Frederic Weisbecker wrote:
quoted hunk ↗ jump to hunk
kernel/sched/idle.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index c174afe1dd17..35d79af3286d 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c@@ -260,6 +260,12 @@ static void do_idle(void) { int cpu = smp_processor_id(); + if (cpu_is_offline(cpu)) {
Does it make sense to make that: if (unlikely(cpu_is_offline(cpu))) ?
+ local_irq_disable();
Also, do we want something like: WARN_ON_ONCE(need_resched()); ?
quoted hunk ↗ jump to hunk
+ cpuhp_report_idle_dead(); + arch_cpu_idle_dead(); + } + /* * Check if we need to update blocked load */@@ -311,11 +317,6 @@ static void do_idle(void) */ local_irq_disable(); - if (cpu_is_offline(cpu)) { - cpuhp_report_idle_dead(); - arch_cpu_idle_dead(); - } - arch_cpu_idle_enter(); rcu_nocb_flush_deferred_wakeup();-- 2.51.1