From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Glauber Costa <glommer@parallels.com>
Cc: linux-kernel@vger.kernel.org, paul@paulmenage.org,
lizf@cn.fujitsu.com, daniel.lezcano@free.fr,
jbottomley@parallels.com
Subject: Re: [RFD 0/9] per-cgroup /proc/stat statistics
Date: Wed, 28 Sep 2011 00:11:53 +0200 [thread overview]
Message-ID: <1317161513.21836.28.camel@twins> (raw)
In-Reply-To: <1316816432-9237-1-git-send-email-glommer@parallels.com>
On Fri, 2011-09-23 at 19:20 -0300, Glauber Costa wrote:
> Hi,
>
> Since I've sent already a RFC about it, I am sending now a RFD.
> If you eager for meaning, this can then be a "Request for Doctors",
> since Peter is likely to have a heart attack now.
:-)
All we need is to ensure the case of cgroups enabled but not used isn't
actually more expensive that what we have now, after that, if people
create a 100 deep cgroup hierarchy they get what they asked.
>From a conceptual pov this patch-set is a lot saner than the previous
one, doesn't duplicate nearly as much and actually tries to improve the
code (although I suspect simply killing off cputime64_t as a whole will
get us even more).
> So here's the deal:
>
> * My main goal here was to demonstrate that we can avoid double accounting
> in a lot of places. So what I did was getting rid of the original and first
> kstat mechanism, and use only cgroups accounting for that. Since the parent
> is always updated, the original stats are the one for the root cgroup.
Right, current patch-set won't compile for those who have CGROUP=n
kernels though, need to find something for that. Shouldn't be too hard
though. It looks like you only need to provide static per-cpu storage
and a custom version of task_cgroup_account_field().
> * I believe that all those cpu cgroups are confusing and should be unified. Not
> that we can simply get rid of it, but my goal here is to provide all the
> information they do, in cpu cgroup. If the set of tasks needed for accounting
> is not independent of the ones in cpu cgroup, we can avoid double accounting
> for that. I default cpuacct to n, but leave it to people that wants to use it
> alone.
Amen! Ideally we place cpuacct on the deprecated list or somesuch..
> * Well, I'm also doing what I was doing originally: Providing a per-cgroup version
> of the /proc/stat file.
Right, so how much sense does it make to keep calling it proc.stat?
next prev parent reply other threads:[~2011-09-27 22:12 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-23 22:20 Glauber Costa
2011-09-23 22:20 ` [RFD 1/9] Change cpustat fields to an array Glauber Costa
2011-09-27 21:00 ` Peter Zijlstra
2011-09-28 15:13 ` Glauber Costa
2011-09-28 15:23 ` Peter Zijlstra
2011-09-28 18:19 ` Glauber Costa
2011-09-28 19:09 ` Peter Zijlstra
2011-09-28 20:04 ` Glauber Costa
2011-10-01 17:47 ` Glauber Costa
2011-09-27 21:03 ` Peter Zijlstra
2011-09-28 15:14 ` Glauber Costa
2011-09-23 22:20 ` [RFD 2/9] Move /proc/stat logic inside sched.c Glauber Costa
2011-09-23 22:20 ` [RFD 3/9] Display /proc/stat information per cgroup Glauber Costa
2011-09-27 17:01 ` Balbir Singh
2011-09-27 18:42 ` Glauber Costa
2011-09-27 22:21 ` Peter Zijlstra
2011-09-28 15:22 ` Glauber Costa
2011-09-28 15:23 ` Glauber Costa
2011-09-27 21:48 ` Peter Zijlstra
2011-09-28 15:14 ` Glauber Costa
2011-09-27 21:52 ` Peter Zijlstra
2011-09-28 15:15 ` Glauber Costa
2011-09-23 22:20 ` [RFD 4/9] Make total_forks per-cgroup Glauber Costa
2011-09-27 22:00 ` Peter Zijlstra
2011-09-28 8:13 ` Martin Schwidefsky
2011-09-28 10:35 ` Peter Zijlstra
2011-09-28 12:42 ` Martin Schwidefsky
2011-09-28 12:53 ` Peter Zijlstra
2011-09-28 15:29 ` Glauber Costa
2011-09-28 15:33 ` Peter Zijlstra
2011-09-28 15:35 ` Glauber Costa
2011-09-28 15:37 ` Peter Zijlstra
2011-09-28 15:39 ` Glauber Costa
2011-09-28 15:28 ` Glauber Costa
2011-09-28 15:27 ` Glauber Costa
2011-09-28 15:26 ` Glauber Costa
2011-09-23 22:20 ` [RFD 5/9] per-cgroup boot time Glauber Costa
2011-09-23 22:20 ` [RFD 6/9] Report steal time for cgroup Glauber Costa
2011-09-23 22:20 ` [RFD 7/9] provide a version of cpuacct statistics inside cpu cgroup Glauber Costa
2011-09-23 22:20 ` [RFD 8/9] provide a version of cpuusage " Glauber Costa
2011-09-23 22:20 ` [RFD 9/9] Change CPUACCT to default n Glauber Costa
2011-09-27 22:11 ` Peter Zijlstra [this message]
2011-09-28 15:21 ` [RFD 0/9] per-cgroup /proc/stat statistics Glauber Costa
2011-09-28 15:27 ` Peter Zijlstra
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