mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "David Schwartz" <davids@webmaster.com>
To: "Andrea Arcangeli" <andrea@suse.de>, <dak@gnu.org>
Cc: <linux-kernel@vger.kernel.org>
Subject: RE: Scheduling problem with 2.4?
Date: Sat, 17 May 2003 17:16:33 -0700	[thread overview]
Message-ID: <MDEHLPKNGKAHNMBLJOLKIELBDAAA.davids@webmaster.com> (raw)
In-Reply-To: <20030517235048.GB1429@dualathlon.random>


> I see what you mean, but I still don't think it is a problem. If
> bandwidth matters you will have to use large writes and reads anyways,
> if bandwidth doesn't matter the number of ctx switches doesn't matter
> either and latency usually is way more important with small messages.

> Andrea

	This is the danger of pre-emption based upon dynamic priorities. You can
get cases where two processes each are permitted to make a very small amount
of progress in alternation. This can happen just as well with large writes
as small ones, the amount of data is irrelevent, it's the amount of CPU time
that's important, or to put it another way, it's how far a process can get
without suffering a context switch.

	I suggest that a process be permitted to use up at least some portion of
its timeslice exempt from any pre-emption based solely on dynamic
priorities.

	DS



  reply	other threads:[~2003-05-18  0:03 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-05-17 11:22 David Kastrup
2003-05-17 17:41 ` Andrea Arcangeli
2003-05-17 19:36   ` David Kastrup
2003-05-17 20:30     ` Andrea Arcangeli
2003-05-17 20:44       ` David Kastrup
2003-05-17 21:53         ` Andrea Arcangeli
2003-05-17 22:37           ` David Kastrup
2003-05-17 23:50             ` Andrea Arcangeli
2003-05-18  0:16               ` David Schwartz [this message]
2003-05-18  1:06                 ` Andrea Arcangeli
2003-05-18  9:41                   ` David Kastrup
2003-05-18  8:55                 ` Mike Galbraith
2003-05-18 17:46                   ` David Schwartz
2003-05-18 23:18                     ` Andrea Arcangeli
2003-05-19  2:59                       ` David Schwartz
2003-05-18 23:11                   ` Andrea Arcangeli
2003-05-19  7:16                     ` Mike Galbraith
2003-05-19  4:02                   ` Mike Galbraith
2003-05-18  0:24               ` David Kastrup
2003-05-17 21:54         ` Barry K. Nathan

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=MDEHLPKNGKAHNMBLJOLKIELBDAAA.davids@webmaster.com \
    --to=davids@webmaster.com \
    --cc=andrea@suse.de \
    --cc=dak@gnu.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

all inboxes | Powered by JetHome®