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Message-ID: <23002f21-9dfb-31b4-c6c7-86f4e292dfea@redhat.com>
Date:   Sun, 12 Jun 2022 22:50:05 -0400
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Subject: Re: [PATCH v11 3/8] cgroup/cpuset: Allow no-task partition to have
 empty cpuset.cpus.effective
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To:     Tejun Heo <tj@kernel.org>
Cc:     Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Shuah Khan <shuah@kernel.org>, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kselftest@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Roman Gushchin <guro@fb.com>, Phil Auld <pauld@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Marcelo Tosatti <mtosatti@redhat.com>,
        =?UTF-8?Q?Michal_Koutn=c3=bd?= <mkoutny@suse.com>
References: <20220510153413.400020-1-longman@redhat.com>
 <20220510153413.400020-4-longman@redhat.com>
 <YqYlCRywdgSYtwKk@slm.duckdns.org>
From:   Waiman Long <longman@redhat.com>
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On 6/12/22 13:40, Tejun Heo wrote:
> Hello,
>
> Sorry about the long delay.
>
> On Tue, May 10, 2022 at 11:34:08AM -0400, Waiman Long wrote:
>> Once a partition with empty "cpuset.cpus.effective" is formed, no
>> new task can be moved into it until "cpuset.cpus.effective" becomes
>> non-empty.
> This is always true due to no-tasks-in-intermediate-cgroups requirement,
> right?

I seems to remember there are corner cases where a task can be moved to 
an intermediate cgroup under circumstances. I need to dig further to 
find out what it is.

Cheers,
Longman