LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: "Paul Menage" <menage@google.com>
To: vatsa@linux.vnet.ibm.com
Cc: containers@lists.linux-foundation.org,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Ingo Molnar" <mingo@elte.hu>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] CFS CGroup: Report usage
Date: Thu, 25 Oct 2007 18:24:55 -0700	[thread overview]
Message-ID: <6599ad830710251824w1e4a2720p90785e148b32f9c2@mail.gmail.com> (raw)
In-Reply-To: <20071024043916.GA5357@linux.vnet.ibm.com>

On 10/23/07, Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> 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?"

Paul

      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]

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=6599ad830710251824w1e4a2720p90785e148b32f9c2@mail.gmail.com \
    --to=menage@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=containers@lists.linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=vatsa@linux.vnet.ibm.com \
    --subject='Re: [PATCH 2/2] CFS CGroup: Report usage' \
    /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

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).