From: Peter Zijlstra <peterz@infradead.org>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Tejun Heo <tj@kernel.org>, Li Zefan <lizf@cn.fujitsu.com>,
containers@lists.linux-foundation.org, cgroups@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Kay Sievers <kay.sievers@vrfy.org>,
Lennart Poettering <lennart@poettering.net>,
Frederic Weisbecker <fweisbec@gmail.com>,
linux-kernel@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>
Subject: Re: [RFD] cgroup: about multiple hierarchies
Date: Fri, 24 Feb 2012 12:33:16 +0100 [thread overview]
Message-ID: <1330083196.11248.24.camel@twins> (raw)
In-Reply-To: <20120223213847.GK19691@redhat.com>
On Thu, 2012-02-23 at 16:38 -0500, Vivek Goyal wrote:
> > > Again, it does not mean I am advocating flat hiearchy. I am just wondering
> > > in case of fully nested hierarchies (task at same level as groups), how
> > > does one explain it to a layman user who understands things in terms of
> > > % of resources.
> >
> > If your complete control is % based then I would assume its a % of a %.
> > Simple enough.
>
> But % of % will vary dynamically and not be static. So if root has got
> 100% of resources and we want 25% of that for a group, then hierarchy
> might look as follows.
>
> root
> / | \
> T1 T2 g1
>
> T1, T2 are tasks and g1 is the group needing 25% of root's resources. Now
> number of tasks running in parallel to g1 will determine its effective %
> and tasks come and go. So the only way to do this would be that move T1
> and T2 in a child group under root and make sure new tasks don't show up
> in root.
Which is exactly that the scheduler stuff does.. so tough luck for the
sysad who can't grasp it.
> Otherwise creating a group under root does not ensure that you get minimum
> % of resource. It just makes sure that you can't get more than 25% of
> % resources when things are tight.
You never said anything about minimum resource guarantees in the initial
problem statement.
next prev parent reply other threads:[~2012-02-24 11:33 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-21 21:19 [RFD] cgroup: about multiple hierarchies Tejun Heo
2012-02-21 21:21 ` Tejun Heo
2012-02-22 13:34 ` Glauber Costa
2012-02-23 7:45 ` Serge E. Hallyn
2012-02-23 17:29 ` Tejun Heo
2012-02-23 18:47 ` Serge Hallyn
2012-02-26 4:59 ` Konstantin Khlebnikov
2012-02-22 13:30 ` Peter Zijlstra
2012-02-22 13:37 ` Glauber Costa
2012-02-22 18:01 ` Tejun Heo
2012-02-23 7:39 ` Li Zefan
2012-02-22 15:45 ` Frederic Weisbecker
2012-02-22 18:22 ` Tejun Heo
2012-02-27 17:46 ` Frederic Weisbecker
2012-02-22 16:38 ` Vivek Goyal
2012-02-22 16:57 ` Vivek Goyal
2012-02-22 18:43 ` Tejun Heo
2012-02-23 9:41 ` Peter Zijlstra
2012-02-23 14:13 ` Peter Zijlstra
2012-03-01 17:19 ` Michal Schmidt
2012-03-01 18:03 ` Peter Zijlstra
2012-03-02 11:08 ` Michal Schmidt
2012-03-02 11:23 ` Peter Zijlstra
2012-03-02 11:28 ` Michal Schmidt
2012-03-02 11:34 ` Peter Zijlstra
2012-03-01 20:26 ` Mike Galbraith
2012-03-01 21:02 ` Vivek Goyal
2012-03-01 22:04 ` Mike Galbraith
2012-03-01 22:38 ` C Anthony Risinger
2012-03-02 10:51 ` Michal Schmidt
2012-03-02 11:52 ` Mike Galbraith
2012-03-05 12:43 ` Lennart Poettering
2012-03-05 15:47 ` Mike Galbraith
2012-03-05 19:58 ` Mike Galbraith
2012-03-02 2:43 ` Kay Sievers
2012-03-02 10:15 ` Peter Zijlstra
2012-03-02 11:16 ` Michal Schmidt
2012-03-02 11:24 ` Peter Zijlstra
2012-02-23 21:38 ` Vivek Goyal
2012-02-23 22:34 ` Tejun Heo
2012-02-28 21:16 ` Vivek Goyal
2012-02-28 21:21 ` Peter Zijlstra
2012-02-28 21:35 ` Vivek Goyal
2012-02-28 21:43 ` Peter Zijlstra
2012-02-28 21:54 ` Vivek Goyal
2012-02-28 22:00 ` Peter Zijlstra
2012-02-28 22:31 ` Vivek Goyal
2012-02-28 21:53 ` Peter Zijlstra
2012-02-28 22:09 ` Vivek Goyal
2012-02-24 11:33 ` Peter Zijlstra [this message]
2012-02-22 18:33 ` Tejun Heo
2012-02-23 19:41 ` Vivek Goyal
2012-02-23 22:38 ` Tejun Heo
2012-02-23 7:59 ` Li Zefan
2012-02-23 20:32 ` Vivek Goyal
2012-02-23 8:22 ` Li Zefan
2012-02-23 17:33 ` Tejun Heo
[not found] ` <m162em2efy.fsf@fess.ebiederm.org>
2012-03-03 14:26 ` Serge Hallyn
2012-03-05 11:37 ` Lennart Poettering
2012-03-12 22:10 ` Tejun Heo
2012-03-12 22:22 ` Peter Zijlstra
2012-03-12 22:28 ` Tejun Heo
2012-03-12 22:31 ` Lennart Poettering
2012-03-12 23:00 ` Tejun Heo
2012-03-12 23:02 ` Peter Zijlstra
2012-03-12 23:09 ` Tejun Heo
2012-03-12 23:43 ` Lennart Poettering
2012-03-12 22:32 ` Peter Zijlstra
2012-03-12 22:39 ` Tejun Heo
2012-03-12 22:44 ` Peter Zijlstra
2012-03-12 23:04 ` Tejun Heo
2012-03-13 14:10 ` Vivek Goyal
2012-03-13 16:11 ` C Anthony Risinger
2012-03-13 16:30 ` C Anthony Risinger
2012-03-13 17:25 ` Peter Zijlstra
2012-03-13 17:31 ` Peter Zijlstra
2012-03-13 10:11 ` Glauber Costa
2012-03-13 14:03 ` Vivek Goyal
2012-03-13 15:59 ` Tejun Heo
2012-03-16 23:14 ` James Bottomley
2012-03-12 22:37 ` Serge Hallyn
2012-03-12 22:55 ` Tejun Heo
2012-03-13 13:49 ` Vivek Goyal
2012-03-13 16:02 ` Tejun Heo
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