From: Glauber Costa <glommer@parallels.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>, <linux-kernel@vger.kernel.org>,
<cgroups@vger.kernel.org>, <devel@openvz.org>,
Tejun Heo <tj@kernel.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
<handai.szj@gmail.com>, <Andrew.Phillips@lmax.com>,
Serge Hallyn <serge.hallyn@canonical.com>
Subject: Re: [PATCH v3 5/6] Also record sleep start for a task group
Date: Wed, 30 May 2012 16:44:09 +0400 [thread overview]
Message-ID: <4FC61619.7000300@parallels.com> (raw)
In-Reply-To: <1338381877.26856.272.camel@twins>
On 05/30/2012 04:44 PM, Peter Zijlstra wrote:
> On Wed, 2012-05-30 at 16:24 +0400, Glauber Costa wrote:
>> sleep_start is not for iowait. This is for idle. And I know no other way
>> to collect idle time per cgroup, other than the time during which it was
>> out of the runqueue.
>>
>> Now what you say about the sleepers don't make that much sense for idle
>> because this information is per-cpu as well.
>>
>> When the se is being dequeued, it means none of its children is running
>> on that runqueue. That's idle.
>
> But does that mean the cgroup is idle? Its impossible to re-construct
> the machine state from this per-cpu data if your definition of
> cgroup-idle is the time when _all_ cpus are idle.
>
It is idle for that runqueue, aka cpu. The cgroup itself is idle when
all cpus are idle. And yes, then you have 2s per sec of idle in a 2-way
system.
That's pretty much how a physical box works as well.
next prev parent reply other threads:[~2012-05-30 12:46 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-30 9:48 [PATCH v3 0/6] per cgroup /proc/stat statistics Glauber Costa
2012-05-30 9:48 ` [PATCH v3 1/6] measure exec_clock for rt sched entities Glauber Costa
2012-05-30 10:29 ` Peter Zijlstra
2012-05-30 10:32 ` Glauber Costa
2012-05-30 10:42 ` Peter Zijlstra
2012-05-30 10:42 ` Glauber Costa
2012-05-30 11:00 ` Paul Turner
2012-05-30 12:09 ` Glauber Costa
2012-05-30 9:48 ` [PATCH v3 2/6] account guest time per-cgroup as well Glauber Costa
2012-05-30 10:32 ` Peter Zijlstra
2012-05-30 10:36 ` Glauber Costa
2012-05-30 10:46 ` Paul Turner
2012-05-30 9:48 ` [PATCH v3 3/6] expose fine-grained per-cpu data for cpuacct stats Glauber Costa
2012-05-30 10:34 ` Peter Zijlstra
2012-05-30 10:34 ` Glauber Costa
2012-05-30 10:43 ` Peter Zijlstra
2012-05-30 10:44 ` Glauber Costa
2012-05-30 11:24 ` Peter Zijlstra
2012-05-30 11:24 ` Paul Turner
2012-05-30 12:20 ` Glauber Costa
2012-05-30 12:48 ` Paul Turner
2012-05-30 12:52 ` Glauber Costa
2012-05-30 13:26 ` Glauber Costa
2012-05-30 13:26 ` Glauber Costa
2012-05-30 9:48 ` [PATCH v3 4/6] add a new scheduler hook for context switch Glauber Costa
2012-05-30 11:20 ` Peter Zijlstra
2012-05-30 11:40 ` Peter Zijlstra
2012-05-30 12:08 ` Glauber Costa
2012-05-30 12:07 ` Glauber Costa
2012-05-30 9:48 ` [PATCH v3 5/6] Also record sleep start for a task group Glauber Costa
2012-05-30 11:35 ` Paul Turner
2012-05-30 12:24 ` Glauber Costa
2012-05-30 12:44 ` Peter Zijlstra
2012-05-30 12:44 ` Glauber Costa [this message]
2012-05-30 9:48 ` [PATCH v3 6/6] expose per-taskgroup schedstats in cgroup Glauber Costa
2012-05-30 11:22 ` Peter Zijlstra
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=4FC61619.7000300@parallels.com \
--to=glommer@parallels.com \
--cc=Andrew.Phillips@lmax.com \
--cc=a.p.zijlstra@chello.nl \
--cc=cgroups@vger.kernel.org \
--cc=devel@openvz.org \
--cc=ebiederm@xmission.com \
--cc=handai.szj@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=pjt@google.com \
--cc=serge.hallyn@canonical.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