From: David Rientjes <rientjes@google.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>,
LKML <linux-kernel@vger.kernel.org>, Tejun Heo <htejun@gmail.com>,
Li Zefan <lizf@cn.fujitsu.com>, Paul Menage <paul@paulmenage.org>
Subject: Re: patch] cpusets, cgroups: disallow attaching kthreadd
Date: Wed, 19 Oct 2011 12:47:32 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.00.1110191243110.2892@chino.kir.corp.google.com> (raw)
In-Reply-To: <1319010659.29774.3.camel@twins>
On Wed, 19 Oct 2011, Peter Zijlstra wrote:
> My thinking is that kthreadd is the mother of all kernel threads and the
> kernel assumes it can spawn kthreads without constraints, a valid
> assumption IMO.
>
Cgroups don't necessarily imply constraints, though, you could devise a
cgroup to just do monitoring or statistics tracking for an aggregate of
tasks and placing kthreadd in such a cgroup would make perfect sense
because then, since children are forked in the same cgroup, you can
monitor or gather statistics for all kthreads. This can be your only
cgroup on the system.
Cpusets, though, does imply cpu constraints, which is why we decline
PF_THREAD_BOUND threads from moving in the first place, which is the
source of Mike's issue. It's can_attach() function can explicitly decline
kthreadd as well since the cpu constraints of both types of threads should
never be altered by either cpusets or sched_setaffinity().
next prev parent reply other threads:[~2011-10-19 19:47 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-23 6:21 [patch] cpusets: allow PF_THREAD_BOUND kworkers to escape from a cpuset Mike Galbraith
2011-09-23 7:00 ` Li Zefan
2011-09-23 7:19 ` Mike Galbraith
2011-09-23 9:12 ` David Rientjes
2011-09-23 9:42 ` Mike Galbraith
2011-09-23 10:53 ` Mike Galbraith
2011-09-23 13:27 ` David Rientjes
2011-09-23 14:33 ` Mike Galbraith
2011-09-23 18:16 ` Mike Galbraith
2011-09-23 20:20 ` David Rientjes
2011-09-24 3:21 ` Tejun Heo
2011-10-10 5:34 ` Mike Galbraith
2011-10-10 8:03 ` [patch] cpusets, cgroups: disallow attaching kthreadd Mike Galbraith
2011-10-10 16:43 ` Tejun Heo
2011-10-11 2:31 ` Mike Galbraith
2011-10-11 14:08 ` Peter Zijlstra
2011-10-11 16:57 ` Mike Galbraith
2011-10-12 1:22 ` David Rientjes
2011-10-12 1:45 ` Mike Galbraith
2011-10-12 1:20 ` David Rientjes
2011-10-18 8:10 ` patch] " Mike Galbraith
2011-10-18 8:16 ` David Rientjes
2011-10-18 8:42 ` Peter Zijlstra
2011-10-18 8:47 ` Mike Galbraith
2011-10-18 9:06 ` Peter Zijlstra
2011-10-18 9:23 ` Mike Galbraith
2011-10-18 10:11 ` Mike Galbraith
2011-10-18 20:38 ` David Rientjes
2011-10-19 4:00 ` Mike Galbraith
2011-10-19 4:53 ` Paul Menage
2011-10-19 4:56 ` Paul Menage
2011-10-19 5:28 ` Mike Galbraith
2011-10-19 7:50 ` Peter Zijlstra
2011-10-19 19:47 ` David Rientjes [this message]
2011-10-20 10:32 ` Peter Zijlstra
2011-10-20 21:24 ` David Rientjes
2011-10-19 4:57 ` Paul Menage
2011-10-19 5:24 ` [patch-final] " Mike Galbraith
2011-10-19 7:54 ` Peter Zijlstra
2011-10-19 8:00 ` Paul Menage
2011-10-19 8:21 ` Mike Galbraith
2011-10-26 20:27 ` David Rientjes
2011-11-10 20:51 ` David Rientjes
2011-12-06 20:13 ` David Rientjes
2011-12-06 22:47 ` Andrew Morton
2011-12-06 23:53 ` David Rientjes
2011-12-07 0:05 ` Andrew Morton
2011-12-07 3:18 ` [resubmit] " Mike Galbraith
2011-12-07 4:36 ` Mike Galbraith
2011-12-07 22:03 ` David Rientjes
2011-12-14 20:16 ` Andrew Morton
2011-12-15 2:50 ` David Rientjes
2012-01-06 22:06 ` Andrew Morton
2012-01-07 6:34 ` Mike Galbraith
2012-01-07 7:59 ` Andrew Morton
2011-12-07 22:01 ` David Rientjes
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