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Sat, 07 Nov 2026 05:13:41 -0800 (PST) Received: from scheduler.schedules ([85.100.66.184]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4b7d54d6f93sm122304385e9.0.2026.11.07.05.13.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Nov 2026 05:13:41 -0800 (PST) Date: Sat, 7 Nov 2026 16:13:38 +0300 From: Kayra Cizmeci To: Peter Zijlstra Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com, joshdon@google.com, tj@kernel.org, jakub@okonski.org Subject: Re: [PATCH v2 2/3] sched/fair: Make cfs_rq::idle the sum of ancestor tg::idle Message-ID: References: <20261105165525.011876858@infradead.org> <20261105170157.616859418@infradead.org> <20261107113639.GK2668200@noisy.programming.kicks-ass.net> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20261107113639.GK2668200@noisy.programming.kicks-ass.net> Hi Peter! On Sat, Nov 07, 2026 at 12:36:39PM +0100, Peter Zijlstra wrote: > > Rather than keeping cfs_rq::idle as a copy of tg::idle, make it the sum of > all ancestor tg::idle. This makes it trivial to tell if the current cgroup > is marked idle somewhere along its ancestral path. > > Signed-off-by: Peter Zijlstra (Intel) First of all, Reviewed-by: Kayra Cizmeci With this, now tasks in an idle cfs_rq cannot be buddies. But IMO that's more of a fix. Maybe it would be good to add a fixes tag? Cheers, Kayra