From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755688Ab0KLVLY (ORCPT ); Fri, 12 Nov 2010 16:11:24 -0500 Received: from ms01.sssup.it ([193.205.80.99]:46124 "EHLO sssup.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755264Ab0KLVLW (ORCPT ); Fri, 12 Nov 2010 16:11:22 -0500 Subject: Re: [RFC][PATCH 07/22] sched: SCHED_DEADLINE push and pull logic From: Raistlin To: Peter Zijlstra Cc: Ingo Molnar , Thomas Gleixner , Steven Rostedt , Chris Friesen , oleg@redhat.com, Frederic Weisbecker , Darren Hart , Johan Eker , "p.faure" , linux-kernel , Claudio Scordino , michael trimarchi , Fabio Checconi , Tommaso Cucinotta , Juri Lelli , Nicola Manica , Luca Abeni , Dhaval Giani , Harald Gustafsson , paulmck In-Reply-To: <1289578673.2084.314.camel@laptop> References: <1288333128.8661.137.camel@Palantir> <1288333935.8661.148.camel@Palantir> <1289578673.2084.314.camel@laptop> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-VvY7PFzAlRnJK8oljeIV" Date: Fri, 12 Nov 2010 22:11:05 +0100 Message-ID: <1289596265.6525.766.camel@Palantir> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-VvY7PFzAlRnJK8oljeIV Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2010-11-12 at 17:17 +0100, Peter Zijlstra wrote: > On Fri, 2010-10-29 at 08:32 +0200, Raistlin wrote: > > Add dynamic migrations to SCHED_DEADLINE, so that tasks can > > be moved among CPUs when necessary. It is also possible to bind a > > task to a (set of) CPU(s), thus restricting its capability of > > migrating, or forbidding migrations at all. > >=20 > > The very same approach used in sched_rt is utilised: > > - -deadline tasks are kept into CPU-specific runqueues, > > - -deadline tasks are migrated among runqueues to achieve the > > following: > > * on an M-CPU system the M earliest deadline ready tasks > > are always running; > > * affinity/cpusets settings of all the -deadline tasks is > > always respected.=20 >=20 > I haven't fully digested the patch, I keep getting side-tracked and its > a large patch..=20 > Yeah, I know, take your time. :-) > however, I thought we would only allow 2 affinities, > strict per-cpu and full root-domain? >=20 Yes, we do! Writing a better changelog for this already noted for next version. > Keep 2 per-cpu utilization counts, a hard-rt and a soft-rt, and ensure > the sum stays <=3D 1. Use the hard-rt one for the planned SF_HARD_RT flag= , > use the soft-rt one for !SF_HARD_RT with nr_cpus_allowed =3D=3D 1, and us= e > \Sum (1-h-s) over the root domain for nr_cpus_allowed !=3D 1. >=20 As agreed during LPC, that's exactly what I'll do. Let's hope to don't screw up while trying to do the math! :-P Thanks, Dario --=20 <> (Raistlin Majere) ---------------------------------------------------------------------- Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy) http://blog.linux.it/raistlin / raistlin@ekiga.net / dario.faggioli@jabber.org --=-VvY7PFzAlRnJK8oljeIV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEABECAAYFAkzdrWkACgkQk4XaBE3IOsRI0QCfcVGBsW4+5MgvXHqSvTngfUr4 gr4Anitb77PwopYf+3NVt3w/TEOdP1wt =L1UL -----END PGP SIGNATURE----- --=-VvY7PFzAlRnJK8oljeIV--