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Date: Mon, 31 Aug 2026 12:37:00 -1000
Message-ID: <16ad7666875543a33b88609ea444fddc@kernel.org>
From: Tejun Heo <tj@kernel.org>
To: Andrea Righi <arighi@nvidia.com>
Cc: David Vernet <void@manifault.com>, Changwoo Min <changwoo@igalia.com>, Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Juri Lelli <juri.lelli@redhat.com>, Vincent Guittot <vincent.guittot@linaro.org>, Dietmar Eggemann <dietmar.eggemann@arm.com>, Steven Rostedt <rostedt@goodmis.org>, Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>, Valentin Schneider <vschneid@redhat.com>, K Prateek Nayak <kprateek.nayak@amd.com>, Tao Cui <cui.tao@linux.dev>, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org, Sashiko <sashiko-bot@kernel.org>
Subject: Re: [PATCH sched_ext/for-7.3-fixes] sched_ext: Serialize cgroup knob updates
In-Reply-To: <20260825092153.2602809-1-arighi@nvidia.com>
References: <20260825092153.2602809-1-arighi@nvidia.com>
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Hello, Andrea.

On Tue, Aug 25, 2026 at 11:21:53AM +0200, Andrea Righi wrote:
> Concurrent cgroup knob writes update the core scheduler under its
> internal locks and notify sched_ext only after those locks are released.

This is the same race Michal's patch fixes by lifting the fair locking
into the core write handlers so that both updates run under the same
lock:

  http://lkml.kernel.org/r/20260824074913.2468177-1-michalblk@google.com

I'm inclined to go with that one.

Thanks.

--
tejun