Date: Tue, 13 Feb 2007 11:18:57 +0530
From: Srivatsa Vaddagiri <vatsa@in.ibm.com>
To: "Paul Menage" <menage@google.com>
Cc: akpm@osdl.org, pj@sgi.com, sekharan@us.ibm.com, dev@sw.ru, xemul@sw.ru,
       serue@us.ibm.com, ebiederm@xmission.com,
       ckrm-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org,
       rohitseth@google.com, mbligh@google.com, winget@google.com,
       containers@lists.osdl.org, devel@openvz.org
Subject: Re: [PATCH 1/7] containers (V7): Generic container system abstracted from cpusets code
Message-ID: <20070213054857.GD22982@in.ibm.com>
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On Mon, Feb 12, 2007 at 11:46:20AM -0800, Paul Menage wrote:
> On further reflection, this probably would be safe after all. Since we
> don't call put_container_group() in attach_task() until after
> synchronize_rcu() completes, that implies that a container_group_get()
> from the RCU section would have already completed. So we should be
> fine.

Right.

Which make me wonder why we need task_lock() at all ..I can understand
the need for a lock like that if we are reading/updating multiple words
in task_struct under the lock. In this case, it is used to read/write
just one pointer, isnt it? I think it can be eliminated all-together
with the use of RCU.


-- 
Regards,
vatsa
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