Date:   Mon, 20 Mar 2023 16:04:33 +0100
From:   Michal =?utf-8?Q?Koutn=C3=BD?= <mkoutny@suse.com>
To:     Waiman Long <longman@redhat.com>
Cc:     Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Shuah Khan <shuah@kernel.org>, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>
Subject: Re: [PATCH v2 3/4] cgroup/cpuset: Include offline CPUs when tasks'
 cpumasks in top_cpuset are updated
Message-ID: <20230320150433.v3xcl7rqsxz4x6tg@blackpad>
References: <20230317151508.1225282-1-longman@redhat.com>
 <20230317151508.1225282-4-longman@redhat.com>
 <20230317180157.uqlleobldg53pgj6@blackpad>
 <11b5454b-42c7-fb0d-f071-c46712f76f3b@redhat.com>
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On Fri, Mar 17, 2023 at 02:05:32PM -0400, Waiman Long <longman@redhat.com> wrote:
> A cpu will be in the subparts_cpus only if it has been given to the child
> partition. So when it becomes online, it will become part of the scheduling
> domain that child partition. Only the tasks in that child partition will get
> their cpumasks updated to use it, not those in the top cpuset.

Right, it's actually the difference between offlining a CPU and giving it
to a sub-partition (hence a removed child (or switched to member) before
CPU onlining). It's clear to me now.

Thanks,
Michal

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