From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory Haskins Subject: Re: RFC: THE OFFLINE SCHEDULER Date: Thu, 27 Aug 2009 23:33:57 -0400 Message-ID: <4A975025.8030500@novell.com> References: <1251282598.3514.20.camel@raz> <1251297910.1791.22.camel@maxim-laptop> <1251298443.4791.7.camel@raz> <1251300625.18584.18.camel@twins> <1251302598.18584.31.camel@twins> <20090826180407.GA13632@elte.hu> <20090826193252.GA14721@elte.hu> <20090826135041.e6169d18.akpm@linux-foundation.org> <4A95A5EE.90400@nortel.com> <1251322663.3882.48.camel@raz> <4A96B997.1070001@nortel.com> <4A97071F.5070804@novell.com> <4A973DAE.4020508@redh at.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig93B83232ABC25043A2695632" Cc: Thomas Gleixner , Christoph Lameter , Chris Friesen , raz ben yehuda , Andrew Morton , mingo@elte.hu, peterz@infradead.org, maximlevitsky@gmail.com, efault@gmx.de, wiseman@macs.biu.ac.il, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org To: Rik van Riel Return-path: In-Reply-To: <4A973DAE.4020508@redhat.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig93B83232ABC25043A2695632 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Rik, Rik van Riel wrote: > Gregory Haskins wrote: >=20 >> 2) Modify FIFO so that it disables tick by default...update accounting= >> info at next reschedule event. >=20 > I like it. The only thing to watch out for is that > events that wake up higher-priority FIFO tasks do > not get deferred :) >=20 Yeah, agreed. My (potentially half-baked) proposal should work at least from a pure scheduling perspective since FIFO technically does not reschedule based on a tick, and wakeups/migrations should still work bidirectionally with existing scheduler policies. However, and to what I believe is your point: its not entirely clear to me what impact, if any, there would be w.r.t. any _other_ events that may be driven off of the scheduler tick (i.e. events other than scheduling policies, like timeslice expiration, etc). Perhaps someone else like Thomas, Ingo, or Peter have some input here. I guess the specific question to ask is: Does the scheduler tick code have any role other than timeslice policies and updating accounting information? Examples would include timer-expiry, for instance. I would think most of this logic is handled by finer grained components like HRT, but I am admittedly ignorant of the actual timer voodoo ;) Kind Regards, -Greg --------------enig93B83232ABC25043A2695632 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.11 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkqXUCUACgkQP5K2CMvXmqEDOgCeOkTQln9Gx/bcBXM8iRZ5faAF dU4An086DWdCFVYr6T0wocVmNMDryvKH =4Xge -----END PGP SIGNATURE----- --------------enig93B83232ABC25043A2695632--