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Wysocki" , Alexander Gordeev , Anna-Maria Behnsen , Ben Segall , Boqun Feng , Christian Borntraeger , Dietmar Eggemann , Heiko Carstens , Ingo Molnar , Jan Kiszka , Joel Fernandes , Juri Lelli , Kieran Bingham , Madhavan Srinivasan , Mel Gorman , Michael Ellerman , Neeraj Upadhyay , Nicholas Piggin , "Paul E . McKenney" , Steven Rostedt , Sven Schnelle , Thomas Gleixner , Uladzislau Rezki , Valentin Schneider , Vasily Gorbik , Vincent Guittot , Viresh Kumar , Xin Zhao , linux-pm@vger.kernel.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 01/15] sched/idle: Handle offlining first in idle loop Message-ID: <20260119125347.GT830755@noisy.programming.kicks-ass.net> References: <20260116145208.87445-1-frederic@kernel.org> <20260116145208.87445-2-frederic@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260116145208.87445-2-frederic@kernel.org> On Fri, Jan 16, 2026 at 03:51:54PM +0100, Frederic Weisbecker wrote: > 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()); ? > + 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 >