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From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
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 15:34:11 +0100	[thread overview]
Message-ID: <20131128143411.GA10872@redhat.com> (raw)
In-Reply-To: <20131128134124.GS10022@twins.programming.kicks-ass.net>

On 11/28, Peter Zijlstra wrote:
>
> On Thu, Nov 28, 2013 at 02:31:52PM +0100, Oleg Nesterov wrote:
> > I _guess_ usermodehelper_init() should use WQ_SYSFS then, and in this case
> > the user can write to wq_cpumask_store somewhere in /sys/.
>
> WTF is that and why are we creating alternative affinity interfaces when
> sched_setaffinity() is a prefectly fine one?

Because there is no a simple workqueue/thread connection, I guess.

And I do not understand why do you dislike this.

For example. Please note that with the new design we can even kill
khelper_wq and the ugly kmod_thread_locker hack (just in case, I am not
saying that the patch which added kmod_thread_locker was ugly ;).

We can just use one of the system_ WQ_UNBOUND workqueues which has
the "large enough" max_active.

Oleg.


  parent reply	other threads:[~2013-11-28 14:33 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
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 [this message]
  -- strict thread matches above, loose matches on Subject: below --
2013-11-29  9:19 zhang.yi20

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