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Date: Fri, 14 Sep 2012 10:59:44 -0700
From: Tejun Heo <tj@kernel.org>
To: Li Zefan <lizefan@huawei.com>
Cc: Glauber Costa <glommer@parallels.com>,
        containers@lists.linux-foundation.org, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org, Michal Hocko <mhocko@suse.cz>,
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        Johannes Weiner <hannes@cmpxchg.org>, Thomas Graf <tgraf@suug.ch>,
        "Serge E. Hallyn" <serue@us.ibm.com>,
        Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
        Neil Horman <nhorman@tuxdriver.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
        "Daniel P. Berrange" <berrange@redhat.com>,
        Lennart Poettering <lennart@poettering.net>,
        Kay Sievers <kay.sievers@vrfy.org>
Subject: Re: [RFC] cgroup TODOs
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Hello,

On Fri, Sep 14, 2012 at 05:12:31PM +0800, Li Zefan wrote:
> Agreed. The biggest issue in cpuset is if hotplug makes a cpuset's cpulist
> empty the tasks in it will be moved to an ancestor cgroup, which requires
> holding cgroup lock. We have to either change cpuset's behavior or eliminate
> the global lock.

Does that have to happen synchronously?  Can't we have a cgroup
operation which asynchronously pushes all tasks in a cgroup to its
parent from a work item?

Thanks.

-- 
tejun