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From: "Paul Menage" <>
	"Andrew Morton" <>,
	"Ingo Molnar" <>,
Subject: Re: [PATCH 2/2] CFS CGroup: Report usage
Date: Thu, 25 Oct 2007 18:24:55 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 10/23/07, Srivatsa Vaddagiri <> wrote:
> agreed, we need to be reporting idle time in (milli)seconds, although
> the requirement we had was to report it back in percentage. I guess the
> percentage figure can be derived from the raw idle time number.
> How about:
>         idle time = t4-t3 (effectively sleep time)
> in the above example?
> > It doesn't seem quite right to me that a cgroup's idle time metric be
> > affected by the activity of other cgroups on the machine,
> I don't see how the idle time metric defined above (t4-t3) can be
> affected by other cgroup activity, unless the execution pattern of one
> cgroup is dependent on the others.

If the other cgroups are busier, and t1-t2 is longer, then the cgroup
will get to the point where it's ready to sleep later in wallclock
time, and t4-t3 will be shorter in absolute terms. If there were no
other cgroups running, then presumably the sleep time would actually
be the sum of those three periods.

Even so, I guess you're right that t4-t3 is the most appropriate thing
to report, as long as people realise that it's a bit of a fuzzy value.

> I think primarily for systems management tools to report back various
> statistics about a OpenVZ/VServer-like container (just like top reports stats
> for a OS currently). Let me check if there are other uses envisoned for
> it.

Sorry, I didn't mean "how will you report it to users?", I meant "what
kinds of useful information will the users be able to get from it?"


      reply	other threads:[~2007-10-26  1:25 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-23  0:49 Paul Menage
2007-10-23  2:40 ` Srivatsa Vaddagiri
2007-10-23  6:06   ` Paul Menage
2007-10-23  7:21     ` Paul Menage
2007-10-23  7:49       ` Balbir Singh
2007-10-23  7:53         ` Paul Menage
2007-10-23  7:57           ` Balbir Singh
2007-10-23  8:08             ` Paul Menage
2007-10-23 16:41     ` Srivatsa Vaddagiri
2007-10-23  3:17 ` Balbir Singh
2007-10-23  6:09   ` Paul Menage
2007-10-23 16:43 ` Srivatsa Vaddagiri
2007-10-23 16:47 ` Srivatsa Vaddagiri
2007-10-23 16:41   ` Paul Menage
2007-10-23 17:38     ` Srivatsa Vaddagiri
2007-10-24  2:28       ` Paul Menage
2007-10-24  4:39         ` Srivatsa Vaddagiri
2007-10-26  1:24           ` Paul Menage [this message]

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