From: Ludovic Drolez <ldrolez@linbox.com>
To: Antonio Vargas <windenntw@gmail.com>
Cc: linux-kernel@vger.kernel.org, subdino2004@yahoo.fr
Subject: Re: [PATCH] sched.c: Be a bit more conservative in SMP
Date: Wed, 20 Sep 2006 09:42:53 +0200 [thread overview]
Message-ID: <4510F0FD.4060602@linbox.com> (raw)
In-Reply-To: <69304d110609191050w777a5c48ibe84bc0e3ce65df3@mail.gmail.com>
Antonio Vargas wrote:
> A variant on this theme would be (not tested or somewhat, just a
> random idea for considering):
>
> 1. find if the process is a cpu-hog, if not then ignore
>
> 2. find somehow how much time has this process on it's current cpu
>
> 3. then, instead of always substracting 1 from th current load on the
> current cpu, substract for example 1...0 when running from 0 to 60
> seconds... this way cpu hogs would only rotate slowly?
>
> in code:
>
> number_to_sub_from_queue_load = (256 - min(256,
> time_from_last_change_of_cpu)) >> 8;
>
> somehow managing to get fixedpoint loadlevels on the runqueues would
> make this work better....
>
Yes ! That might be a better idea !
In fact, I tested the 1st patch on our cluster (Finite elements computing on 8
CPUs):
- Under Windows: 875 seconds
- Linux 2.6.16 : 1019 s
- Linux 2.6.16 + manual taskset : 842 s
- Linux 2.6.16 + Vincent's patch : 1373 s :-(
If you find time to write a patch, Antonio, I would be pleased to try it !
Cheers,
--
Ludovic DROLEZ
http://lrs.linbox.org - Free asset management software
next prev parent reply other threads:[~2006-09-20 7:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-03 13:41 [PATCH] sched.c: Be a bit more conservative in SMP Vincent Pelletier
2006-09-03 17:10 ` Vincent Pelletier
2006-09-06 23:30 ` Vincent Pelletier
2006-09-19 14:06 ` Ludovic Drolez
2006-09-19 17:50 ` Antonio Vargas
2006-09-20 7:42 ` Ludovic Drolez [this message]
2006-09-20 16:26 ` Poor scheduling when not loaded at 100% (Was: [PATCH] sched.c: Be a bit more conservative in SMP) Ludovic Drolez
2006-09-21 18:36 ` [PATCH] sched.c: Be a bit more conservative in SMP Vincent Pelletier
2006-09-22 7:24 ` Ludovic Drolez
2006-09-22 12:31 ` Antonio Vargas
2006-09-19 13:39 ` Ludovic
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=4510F0FD.4060602@linbox.com \
--to=ldrolez@linbox.com \
--cc=linux-kernel@vger.kernel.org \
--cc=subdino2004@yahoo.fr \
--cc=windenntw@gmail.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox