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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: References: <20260116145208.87445-1-frederic@kernel.org> <20260116145208.87445-2-frederic@kernel.org> <20260119125347.GT830755@noisy.programming.kicks-ass.net> 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Le Tue, Jan 20, 2026 at 09:56:12AM +0530, K Prateek Nayak a écrit : > Hello Frederic, Peter, > > On 1/20/2026 2:34 AM, Frederic Weisbecker wrote: > > 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: > >> > >>> 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! > > nit. but don't we inherit it from: > > #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) > > so it will end up being annotated with unlikely() no? Ah right! > > -- > Thanks and Regards, > Prateek > -- Frederic Weisbecker SUSE Labs