From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <htejun@gmail.com>,
zhang.yi20@zte.com.cn, 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
Date: Thu, 28 Nov 2013 14:39:47 +0100 [thread overview]
Message-ID: <20131128133947.GR10022@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20131128133152.GA821@redhat.com>
On Thu, Nov 28, 2013 at 02:31:52PM +0100, Oleg Nesterov wrote:
> On 11/28, Peter Zijlstra wrote:
> >
> > On Thu, Nov 28, 2013 at 12:45:42PM +0100, Oleg Nesterov wrote:
> > > It has? khelper is a workqueue thread, this flag is set by create_worker().
> > >
> > > And it does kernel_thread() (not kthread_create()) so the child gets this
> > > flag too.
> >
> > Urgh, but that's still completely wrong. khelper is a singlethread
> > workqueue, those should be unbound and therefore should not have this
> > flag set at all.
>
> Well. This is debatable, but I leave this to you and Tejun ;)
How can that be debatable? I don't see a single argument in favour of
doing that; its plain ridiculous.
> > In fact, I know people want to set affinity on khelper
>
> This is not that simple. Note that khelper itself is the rescuer thread,
> it doesn't not process the works. There are other kworker/u* threads which
> run the work queued on khelper_wq. There is a pool of threads.
That's just fucked. WTF does singlethreaded mean then?
A single parent process for all usermode helpers makes so much sense;
not doing it is just weird.
next prev parent reply other threads:[~2013-11-28 13:39 UTC|newest]
Thread overview: 69+ 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
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 [this message]
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
2013-11-29 9:19 zhang.yi20
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