Re: [PATCH 01/15] sched/idle: Handle offlining first in idle loop

Le Mon, Jan 19, 2026 at 01:53:47PM +0100, Peter Zijlstra a écrit :

On Fri, Jan 16, 2026 at 03:51:54PM +0100, Frederic Weisbecker wrote:

quoted

 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))) ?

Yes indeed!

quoted

+		local_irq_disable();

Also, do we want something like:

		WARN_ON_ONCE(need_resched());

?

Definetly.

Thanks.

-- 
Frederic Weisbecker
SUSE Labs