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Message-ID: <6599ad830710030851jb44f00ft9634f9381218b6e9@mail.gmail.com>
Date: Wed, 3 Oct 2007 08:51:41 -0700
From: "Paul Menage" <menage@google.com>
To: "Paul Jackson" <pj@sgi.com>
Subject: Re: [PATCH] task containersv11 add tasks file interface fix for cpusets
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
       "Nick Piggin" <nickpiggin@yahoo.com.au>,
       "Peter Zijlstra" <a.p.zijlstra@chello.nl>,
       "Serge E. Hallyn" <serue@us.ibm.com>,
       "Cedric Le Goater" <clg@fr.ibm.com>, linux-kernel@vger.kernel.org,
       "Eric W. Biederman" <ebiederm@xmission.com>,
       "David Rientjes" <rientjes@google.com>,
       "Vaidyanathan Srinivasan" <svaidy@linux.vnet.ibm.com>,
       "Pavel Emelianov" <xemul@openvz.org>, containers@lists.osdl.org,
       balbir@linux.vnet.ibm.com
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On 10/3/07, Paul Jackson <pj@sgi.com> wrote:
> From: Paul Jackson <pj@sgi.com>
>
> The code in kernel/cgroup.c attach_task() which skips the
> attachment of a task to the group it is already in has to be
> removed.  Cpusets depends on reattaching a task to its current
> cpuset, in order to trigger updating the cpus_allowed mask in the
> task struct.

Can you explain a bit more about why this is needed? (i.e. specific
scenarios where cpusets will break without this change).

What triggers the reattach in normal use? Something from userspace?

Paul