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Date: Thu, 28 Nov 2013 10:13:58 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Tejun Heo <htejun@gmail.com>
Cc: zhang.yi20@zte.com.cn, Oleg Nesterov <oleg@redhat.com>,
        lkml <linux-kernel@vger.kernel.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into
 userspace child
Message-ID: <20131128091358.GH10022@twins.programming.kicks-ass.net>
References: <20131114114039.GA29277@redhat.com>
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On Wed, Nov 27, 2013 at 01:31:17PM -0500, Tejun Heo wrote:
> On Wed, Nov 27, 2013 at 10:07:03AM +0800, zhang.yi20@zte.com.cn wrote:
> > Userspace process doesn't want the PF_NO_SETAFFINITY, but its parent may be
> > a kernel worker thread which has PF_NO_SETAFFINITY set, and this worker thread
> > can do kernel_thread() to create the child.
> > Clearing this flag in usersapce child to enable its migrating capability.
> > 
> > 
> > Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
> 
> Acked-by: Tejun Heo <tj@kernel.org>
> 
> cc'ing Ingo and Peter.  Ingo, I think this one doesn't really suit the
> workqueue tree.  Can you please pick this one up w/ Oleg's ack added
> and stable cc'd?  The original patch is
> 
>   http://article.gmane.org/gmane.linux.kernel/1602429/raw

So I don't get the problem; aren't all usermode helper thingies spawned
by the khelper task, which doesn't have PG_NO_SETAFFINITY set?

So how come this is a problem?

The Changelog is not explaining anything much -- so no I will not take
this patch.