From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>,
Mike Galbraith <mgalbraith@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>, Paul Menage <paul@paulmenage.org>,
LKML <linux-kernel@vger.kernel.org>,
Li Zefan <lizefan@huawei.com>
Subject: Re: [patch 0/2] cpusets, cpu_cgroup: disallow attaching kthreadd
Date: Fri, 06 Apr 2012 20:26:10 +0200 [thread overview]
Message-ID: <1333736770.2960.114.camel@laptop> (raw)
In-Reply-To: <20120406155203.GA4798@dhcp-172-17-108-109.mtv.corp.google.com>
On Fri, 2012-04-06 at 08:52 -0700, Tejun Heo wrote:
> Hello, David.
>
> On Thu, Apr 05, 2012 at 04:40:06PM -0700, David Rientjes wrote:
> > Well, I'm fussing over it because the patch being considered unnecessary
> > requires that kthreadd can't be moved anywhere and I know one company is
> > trying to move in a direction where nothing is in the root memcg.
>
> "Nothing in the root memcg" can't be a goal in and of itself. You
> want that to achieve some functional goal and I'm trying to say this
> specific kthreadd change doesn't necessarily affect the goal - better
> accounting - all that much. If root group is gonna be completely
> empty otherwise, just combine information from it. Even if that
> doesn't work, assigning specific kthreads to appropriate cgroups after
> the creation wouldn't be too far off. I just don't see how relevant
> it actually would be.
>
> If we want all controlles to play by the same rules, which is
> necessary for having a unified hierarchy, I wanna keep those rules
> simple. If bound kthreads in !root cgroups cause issues for some and
> there aren't quite strong reasons to do otherwise, I would just
> restrict them in the root. It's not like those kthreads are
> cgroup-aware in any form anyway.
>
> I don't know. Just proceed without kthreadd in the root. If the
> fallouts are big enough and can't be easily worked around, let's talk
> then.
Furthermore, the whole point of kthreadd's existence is so that we could
create kthreads without context. Placing it in a cgroup will ensure all
subsequently created kthreads do have context (including possible idle
threads). This seems like a particularly bad idea.
next prev parent reply other threads:[~2012-04-06 18:58 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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1333736770.2960.114.camel@laptop \
--to=a.p.zijlstra@chello.nl \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan@huawei.com \
--cc=mgalbraith@suse.de \
--cc=mingo@redhat.com \
--cc=paul@paulmenage.org \
--cc=rientjes@google.com \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).