From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: zhang.yi20@zte.com.cn, linux-kernel@vger.kernel.org,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: Re: kmod: avoid propagating PF_NO_SETAFFINITY into userspace child
Date: Thu, 14 Nov 2013 12:40:39 +0100 [thread overview]
Message-ID: <20131114114039.GA29277@redhat.com> (raw)
In-Reply-To: <20131114052326.GA29031@mtj.dyndns.org>
On 11/14, Tejun Heo wrote:
>
> Hello,
>
> On Thu, Nov 14, 2013 at 09:51:47AM +0800, zhang.yi20@zte.com.cn wrote:
> > The kernel worker thread has the PF_NO_SETAFFINITY flag, and it is propagated
> > into the userspace child. Clearing this flag in usersapce child to enable its
> > migrating capability.
> >
> >
> > Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
> >
> > --- linux3-12/kernel/kmod.c 2013-11-14 09:06:58.991781656 +0000
> > +++ linux3-12/kernel/kmod.c 2013-11-14 09:08:47.511781621 +0000
> > @@ -217,6 +217,7 @@ static int ____call_usermodehelper(void
> > * Avoid propagating that into the userspace child.
> > */
> > set_user_nice(current, 0);
> > + current->flags &= ~PF_NO_SETAFFINITY;
>
> I'm a bit confused. kernel_thread() doesn't use workqueue or
> kthread_bind(),
Yes, but kernel_thread() is called by the worker thread which has
PF_NO_SETAFFINITY, this flag is copied to child->flags.
Looks like Zhang is right... But I'd suggest to change flush_old_exec()
instead (see "current->flags &= ...").
Oleg.
next prev parent reply other threads:[~2013-11-14 11:39 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 1:51 kmod: avoid propagating PF_NO_SETAFFINITY into userspace child zhang.yi20
2013-11-14 5:23 ` Tejun Heo
2013-11-14 11:40 ` Oleg Nesterov [this message]
2013-11-14 11:55 ` [PATCH 0/1]: (Was: kmod: avoid propagating PF_NO_SETAFFINITY into userspace child) Oleg Nesterov
2013-11-14 11:56 ` [PATCH 1/1] workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY Oleg Nesterov
2013-11-22 23:13 ` Tejun Heo
[not found] ` <OF36E72FA9.51146BE3-ON48257C2E.0008BC6D-48257C2E.0008FF9C@zte.com.cn>
2013-11-25 12:14 ` 答复: " Oleg Nesterov
2013-11-26 2:10 ` [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child zhang.yi20
2013-11-26 18:04 ` Oleg Nesterov
2013-11-27 2:07 ` zhang.yi20
2013-11-27 13:20 ` Oleg Nesterov
2013-11-27 18:31 ` Tejun Heo
2013-11-28 9:13 ` Peter Zijlstra
2013-11-28 11:45 ` Oleg Nesterov
2013-11-28 12:17 ` Peter Zijlstra
2013-11-28 13:31 ` Oleg Nesterov
2013-11-28 13:39 ` Peter Zijlstra
2013-11-28 14:13 ` Tejun Heo
2013-11-28 14:31 ` Peter Zijlstra
2013-11-28 14:38 ` Tejun Heo
2013-11-28 14:47 ` Peter Zijlstra
2013-11-28 14:51 ` Tejun Heo
2013-11-28 14:55 ` Peter Zijlstra
2013-11-28 14:57 ` Tejun Heo
2013-11-28 14:59 ` Peter Zijlstra
2013-11-28 15:07 ` Tejun Heo
2013-11-28 15:17 ` Peter Zijlstra
2013-11-28 15:39 ` Tejun Heo
2013-11-28 16:33 ` Peter Zijlstra
2013-11-29 14:33 ` Tejun Heo
2013-11-28 15:47 ` Oleg Nesterov
2013-11-28 16:07 ` Oleg Nesterov
2013-11-28 14:43 ` Peter Zijlstra
2013-11-28 14:53 ` Tejun Heo
2013-11-28 14:57 ` Peter Zijlstra
2013-11-28 15:02 ` Tejun Heo
2013-11-28 15:07 ` Peter Zijlstra
2013-11-28 15:10 ` Tejun Heo
2013-11-28 15:18 ` Peter Zijlstra
2013-11-28 14:38 ` Peter Zijlstra
2013-11-28 14:45 ` Tejun Heo
2013-11-28 14:53 ` Peter Zijlstra
2013-11-28 15:34 ` Oleg Nesterov
2013-11-28 15:40 ` Peter Zijlstra
2013-11-28 16:20 ` Oleg Nesterov
2013-11-28 16:38 ` Peter Zijlstra
2013-11-28 18:13 ` Oleg Nesterov
2013-11-28 14:23 ` Oleg Nesterov
2013-11-28 14:31 ` Tejun Heo
2013-11-28 15:00 ` Oleg Nesterov
2013-11-28 15:02 ` Peter Zijlstra
2013-11-28 19:33 ` [PATCH 0/1] usermodehelper: kill ____call_usermodehelper()->set_cpus_allowed_ptr() Oleg Nesterov
2013-11-28 19:33 ` [PATCH 1/1] " Oleg Nesterov
2013-11-29 13:44 ` Tejun Heo
2013-11-29 16:49 ` Oleg Nesterov
2013-12-05 14:21 ` Frederic Weisbecker
2013-12-05 14:37 ` Oleg Nesterov
2013-12-05 14:39 ` Tejun Heo
2013-12-05 15:30 ` Oleg Nesterov
2013-12-05 19:13 ` Christoph Lameter
2013-12-06 14:53 ` Oleg Nesterov
2013-12-06 15:37 ` Christoph Lameter
2013-12-06 15:56 ` Oleg Nesterov
2013-12-05 16:26 ` Frederic Weisbecker
2013-12-05 14:42 ` Frederic Weisbecker
2013-11-28 13:41 ` [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child Peter Zijlstra
2013-11-28 14:05 ` Tejun Heo
2013-11-28 14:34 ` Oleg Nesterov
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