All of lore.kernel.org
 help / color / mirror / Atom feed
From: Con Kolivas <kernel@kolivas.org>
To: ck@vds.kolivas.org
Cc: Ingo Molnar <mingo@elte.hu>, Michael Gerdau <mgd@technosis.de>,
	Nick Piggin <npiggin@suse.de>, Bill Davidsen <davidsen@tmr.com>,
	Juliusz Chroboczek <jch@pps.jussieu.fr>,
	Mike Galbraith <efault@gmx.de>,
	linux-kernel@vger.kernel.org,
	William Lee Irwin III <wli@holomorphy.com>,
	Peter Williams <pwil3058@bigpond.net.au>,
	Gene Heskett <gene.heskett@gmail.com>, Willy Tarreau <w@1wt.eu>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Arjan van de Ven <arjan@infradead.org>
Subject: Re: [ck] Re: [REPORT] cfs-v6-rc2 vs sd-0.46 vs 2.6.21-rc7
Date: Fri, 27 Apr 2007 08:59:36 +1000	[thread overview]
Message-ID: <200704270859.37931.kernel@kolivas.org> (raw)
In-Reply-To: <20070426120723.GA4092@elte.hu>

On Thursday 26 April 2007 22:07, Ingo Molnar wrote:
> * Michael Gerdau <mgd@technosis.de> wrote:
> > Hi list,
> >
> > find below a test comparing
> >     2.6.21-rc7 (mainline)
> >     2.6.21-rc7-sd046
> >     2.6.21-rc7-cfs-v6-rc2(*) (X @ nice 0)
> >     2.6.21-rc7-cfs-v6-rc2(*) (X @ nice -10)
> > running on a dualcore x86_64.
>
> thanks for the testing!

Very interesting indeed but fairly complicated as well.

> as a summary: i think your numbers demonstrate it nicely that the
> shorter 'timeslice length' that both CFS and SD utilizes does not have a
> measurable negative impact on your workload. To measure the total impact
> of 'timeslicing' you might want to try the exact same workload with a
> much higher 'timeslice length' of say 400 msecs, via:
>
>     echo 400000000 > /proc/sys/kernel/sched_granularity_ns  # on CFS
>     echo 400 > /proc/sys/kernel/rr_interval                 # on SD

I thought that the effective "timeslice" on CFS was double the 
sched_granularity_ns so wouldn't this make the effective timeslice double 
that of what you're setting SD to? Anyway the difference between 400 and 
800ms timeslices is unlikely to be significant so I don't mind.

-- 
-ck

  parent reply	other threads:[~2007-04-26 23:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-26 11:12 [REPORT] cfs-v6-rc2 vs sd-0.46 vs 2.6.21-rc7 Michael Gerdau
2007-04-26 12:07 ` Ingo Molnar
2007-04-26 13:22   ` Michael Gerdau
2007-04-26 13:55     ` Ingo Molnar
2007-04-26 22:59   ` Con Kolivas [this message]
2007-04-27  5:59     ` [ck] " Michael Gerdau
2007-04-27  6:52     ` Ingo Molnar

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=200704270859.37931.kernel@kolivas.org \
    --to=kernel@kolivas.org \
    --cc=akpm@linux-foundation.org \
    --cc=arjan@infradead.org \
    --cc=ck@vds.kolivas.org \
    --cc=davidsen@tmr.com \
    --cc=efault@gmx.de \
    --cc=gene.heskett@gmail.com \
    --cc=jch@pps.jussieu.fr \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mgd@technosis.de \
    --cc=mingo@elte.hu \
    --cc=npiggin@suse.de \
    --cc=pwil3058@bigpond.net.au \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=w@1wt.eu \
    --cc=wli@holomorphy.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.