Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 6 Mar 2003 17:25:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 6 Mar 2003 17:25:08 -0500 Received: from mailout10.sul.t-online.com ([194.25.134.21]:9125 "EHLO mailout10.sul.t-online.com") by vger.kernel.org with ESMTP id ; Thu, 6 Mar 2003 17:25:05 -0500 Date: Thu, 6 Mar 2003 23:35:18 +0100 From: Martin Waitz To: Robert Love Cc: Linus Torvalds , Andrew Morton , mingo@elte.hu, linux-kernel@vger.kernel.org Subject: Re: [patch] "HT scheduler", sched-2.5.63-B3 Message-ID: <20030306223518.GB1326@admingilde.org> Mail-Followup-To: Robert Love , Linus Torvalds , Andrew Morton , mingo@elte.hu, linux-kernel@vger.kernel.org References: <20030228202555.4391bf87.akpm@digeo.com> <20030306220307.GA1326@admingilde.org> <1046988457.715.37.camel@phantasy.awol.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="gatW/ieO32f1wygP" Content-Disposition: inline In-Reply-To: <1046988457.715.37.camel@phantasy.awol.org> User-Agent: Mutt/1.5.3i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3092 Lines: 80 --gatW/ieO32f1wygP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Mar 06, 2003 at 05:07:37PM -0500, Robert Love wrote: > On Thu, 2003-03-06 at 17:03, Martin Waitz wrote: >=20 > > RE: the patch, i think using sleep_avg is a wrong metric from the > > beginning. > Eh? It is as close to a heuristic of interactivity as I can think of. processes tend to max out at one extreme or the other processes that get stalled by a huge overall load of the machine are forced to sleep, too; yet they are not interactive. priority should be based on things the processes did, not on what they haven't done. > > in addition, timeslices should be shortest for high priority processes > > (depending on dynamic prio, not static) >=20 > No, they should be longer. In some cases they should be nearly > infinitely long (which is sort of what we do with the reinsertion into > the active array for highly interactive tasks). We want interactive > tasks to always be able to run. but for interactive tasks, latency is all-important if the task can't provide a result in a short timeslice it already failed to provide low latency and should not be considered interactive any more. when the dynamic prio of the currently running process is high, then only interactive processes should run. but these processes should be rescheduled fast, to provide low-latency equally to all interactive processes when the dynamic prio of the currently running process is low then no interactive process runs and the scheduler can resort to a more batch-job mode: increase timeslices to reduce scheduling overhead. > You may think they need shorter timeslice because they are I/O-bound.=20 > Keep in mind they need not _use_ all their timeslice in one go, and > having a large timeslice ensures they have timeslice available when they > wake up and need to run. but the time slice should not be large enough to stall other processes, which is extremely important for interactivity --=20 CU, / Friedrich-Alexander University Erlangen, Germany Martin Waitz // [Tali on IRCnet] [tali.home.pages.de] _________ ______________/// - - - - - - - - - - - - - - - - - - - - /// dies ist eine manuell generierte mail, sie beinhaltet // tippfehler und ist auch ohne grossbuchstaben gueltig. / - Wer bereit ist, grundlegende Freiheiten aufzugeben, um sich=20 kurzfristige Sicherheit zu verschaffen, der hat weder Freiheit=20 noch Sicherheit verdient. Benjamin Franklin (1706 - 1790) --gatW/ieO32f1wygP Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE+Z80mj/Eaxd/oD7IRAupfAJ97/REV2g5+V+8u53uQdZbIdz8y5ACfYzgE HbxY43RzFbyhJfXhA/yXj0A= =L/O4 -----END PGP SIGNATURE----- --gatW/ieO32f1wygP-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/