linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
To: Con Kolivas <kernel@kolivas.org>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>,
	linux kernel mailing list <linux-kernel@vger.kernel.org>,
	ck list <ck@vds.kolivas.org>
Subject: Re: RSDL v0.30 cpu scheduler for mainline kernels
Date: Thu, 15 Mar 2007 10:46:54 -0700	[thread overview]
Message-ID: <20070315174654.GB12447@linux-os.sc.intel.com> (raw)
In-Reply-To: <200703151705.13761.kernel@kolivas.org>

On Thu, Mar 15, 2007 at 05:05:13PM +1100, Con Kolivas wrote:
> On Thursday 15 March 2007 13:31, Siddha, Suresh B wrote:
> > Just to see the % increase in number of context switches, I ran 8 infinite
> > loops (simple while(1); 's) and with 2.6.21-rc3 I see ~70 context switches
> > every second, whereas with RSDL I see ~530 context switches.
> 
> Thanks. If it's just that then scaling rr interval with cpus somewhat would
> help. If you could, the following patch just to test might confirm that.
> -#define RR_INTERVAL		((6 * HZ / 1001) + 1)
> +#define RR_INTERVAL		((12 * HZ / 1001) + 1)

Context switches now are ~370 per second. Still much above the regular ~70
we see in the mainline.

why do you say the rr_interval needs to be scaled with cpus? The basic point
in RSDL is, if we have more than one same priority task on a single logic
cpu, context switch happens every RR_INTERVAL (6 or 12 msec) whereas in
mainline it happens every 100 msec.

We need to minimize these context switches.

thanks,
suresh

  reply	other threads:[~2007-03-15 17:47 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-11 23:58 RSDL v0.30 cpu scheduler for mainline kernels Con Kolivas
2007-03-12 23:46 ` David Miller
2007-03-13  3:05   ` Con Kolivas
2007-03-13  4:32     ` Willy Tarreau
2007-03-13  5:03       ` [ck] " Felipe Alfaro Solana
2007-03-13  5:29       ` David Miller
2007-03-13 13:10       ` [ck] " michael chang
2007-03-13 15:35 ` [ck] " Ash Milsted
2007-03-13 15:46   ` Con Kolivas
2007-03-13 15:53   ` Lee Revell
2007-03-13 17:45     ` Chris Friesen
2007-03-13 20:02       ` Lee Revell
2007-03-14  9:47       ` Ash Milsted
2007-03-15  2:31 ` Siddha, Suresh B
2007-03-15  6:05   ` Con Kolivas
2007-03-15 17:46     ` Siddha, Suresh B [this message]
2007-03-15 18:58       ` Ray Lee
2007-03-15 21:11         ` Con Kolivas
2007-03-15 21:12         ` Siddha, Suresh B
2007-03-17 14:27 ` Szonyi Calin

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=20070315174654.GB12447@linux-os.sc.intel.com \
    --to=suresh.b.siddha@intel.com \
    --cc=ck@vds.kolivas.org \
    --cc=kernel@kolivas.org \
    --cc=linux-kernel@vger.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;
as well as URLs for NNTP newsgroup(s).