From: Tejun Heo <tj@kernel.org>
To: Mike Galbraith <mgalbraith@suse.de>
Cc: Li Zefan <lizefan@huawei.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
David Rientjes <rientjes@google.com>,
Paul Menage <paul@paulmenage.org>,
LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [patch] cgroups: disallow attaching kthreadd
Date: Mon, 23 Apr 2012 11:05:05 -0700 [thread overview]
Message-ID: <20120423180505.GC5406@google.com> (raw)
In-Reply-To: <1334992426.5428.7.camel@marge.simpson.net>
On Sat, Apr 21, 2012 at 09:13:46AM +0200, Mike Galbraith wrote:
> On Sat, 2012-04-21 at 14:54 +0800, Li Zefan wrote:
>
> > forgot rcu_read_unlock() ?
>
> Eek, we don't need another one of those. Thanks.
>
> > Otherwise Acked-by: Li Zefan <lizefan@huawei.com>
>
> cgroups: disallow attaching kthreadd or PF_THREAD_BOUND threads
>
> Allowing kthreadd to be moved to a non-root group makes no sense, it being
> a global resource, and needlessly leads unsuspecting users toward trouble.
>
> 1. An RT workqueue worker thread spawned in a task group with no rt_runtime
> allocated is not schedulable. Simple user error, but harmful to the box.
>
> 2. A worker thread which acquires PF_THREAD_BOUND can never leave a cpuset,
> rendering the cpuset immortal.
>
> Save the user some unexpected trouble, just say no.
>
> Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Acked-by: Thomas Gleixner <tglx@linutronix.de>
> Acked-by: Li Zefan <lizefan@huawei.com>
Applied to cgroup/for-3.5. Thanks.
--
tejun
prev parent reply other threads:[~2012-04-23 18:05 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-03 17:58 [patch] cgroups: disallow attaching kthreadd Mike Galbraith
2012-04-03 18:49 ` Tejun Heo
2012-04-04 2:34 ` Mike Galbraith
2012-04-04 23:06 ` Tejun Heo
2012-04-04 23:10 ` Tejun Heo
2012-04-04 7:15 ` David Rientjes
2012-04-04 10:38 ` Mike Galbraith
2012-04-04 11:29 ` David Rientjes
2012-04-04 12:30 ` Mike Galbraith
2012-04-04 21:17 ` David Rientjes
2012-04-04 23:09 ` Tejun Heo
2012-04-04 23:14 ` David Rientjes
2012-04-05 4:47 ` Mike Galbraith
2012-04-05 4:58 ` David Rientjes
2012-04-05 5:49 ` Mike Galbraith
2012-04-05 6:07 ` David Rientjes
2012-04-05 6:42 ` Mike Galbraith
2012-04-05 6:49 ` David Rientjes
2012-04-05 7:14 ` [patch 0/2] cpusets, cpu_cgroup: " David Rientjes
2012-04-05 7:14 ` [patch 1/2] cpusets: " David Rientjes
2012-04-05 7:14 ` [patch 2/2] cpu_cgroup: " David Rientjes
2012-04-05 16:08 ` [patch 0/2] cpusets, " Tejun Heo
2012-04-05 21:26 ` David Rientjes
2012-04-05 21:37 ` Tejun Heo
2012-04-05 21:46 ` Tejun Heo
2012-04-06 7:50 ` Li Zefan
2012-04-06 15:54 ` Tejun Heo
2012-04-05 22:03 ` David Rientjes
2012-04-05 22:24 ` Tejun Heo
2012-04-05 22:31 ` Tejun Heo
2012-04-05 22:55 ` David Rientjes
2012-04-05 22:58 ` Tejun Heo
2012-04-05 23:05 ` David Rientjes
2012-04-05 23:13 ` Tejun Heo
2012-04-05 23:40 ` David Rientjes
2012-04-06 15:52 ` Tejun Heo
2012-04-06 18:26 ` Peter Zijlstra
2012-04-06 20:49 ` David Rientjes
2012-04-07 15:02 ` Hiroyuki Kamezawa
2012-04-10 0:52 ` David Rientjes
2012-04-14 11:35 ` Peter Zijlstra
2012-04-20 17:55 ` Tejun Heo
2012-04-06 20:46 ` David Rientjes
2012-04-14 11:28 ` Peter Zijlstra
2012-04-05 7:36 ` [patch] cgroups: " Mike Galbraith
2012-04-05 8:00 ` David Rientjes
2012-04-14 11:17 ` Peter Zijlstra
2012-04-05 16:11 ` Tejun Heo
2012-04-20 17:57 ` Tejun Heo
2012-04-21 5:31 ` Mike Galbraith
2012-04-21 6:54 ` Li Zefan
2012-04-21 7:13 ` Mike Galbraith
2012-04-23 18:05 ` Tejun Heo [this message]
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