From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753675AbaGTGwU (ORCPT ); Sun, 20 Jul 2014 02:52:20 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:45077 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525AbaGTGwS (ORCPT ); Sun, 20 Jul 2014 02:52:18 -0400 Date: Sun, 20 Jul 2014 08:52:07 +0200 From: Peter Zijlstra To: Mike Galbraith Cc: Vincent Guittot , LKML Subject: Re: 143e1e28 sched: Rework sched_domain topology definition Message-ID: <20140720065207.GU9918@twins.programming.kicks-ass.net> References: <1405838616.6512.42.camel@marge.simpson.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jhQDtFD6/0rlgiNE" Content-Disposition: inline In-Reply-To: <1405838616.6512.42.camel@marge.simpson.net> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --jhQDtFD6/0rlgiNE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jul 20, 2014 at 08:43:36AM +0200, Mike Galbraith wrote: > Hi, >=20 > +/* > + * Topology list, bottom-up. > + */ > +static struct sched_domain_topology_level default_topology[] =3D { > +#ifdef CONFIG_SCHED_SMT > + { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, > +#endif > +#ifdef CONFIG_SCHED_MC > + { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, > +#endif > +#ifdef CONFIG_SCHED_BOOK > + { cpu_book_mask, SD_INIT_NAME(BOOK) }, > +#endif > + { cpu_cpu_mask, SD_INIT_NAME(DIE) }, > + { NULL, }, > +}; >=20 > Why did this commit rename the CPU domain to DIE? Because they're both wrong, but we found that DIE was less wrong than CPU. Seeing how CPU typically means 1 logical, well, CPU, in the scheduler, and not the package you stick on your board. We chose DIE over PACKAGE due to 1) its shorter name and 2) things like interlagos which have multiple DIEs in one PACKAGE etc.. Also, the only person who would ever care is the one who (with SCHED_DEBUG) enabled looks at the topology setup, which is maybe all of us 5. --jhQDtFD6/0rlgiNE Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTy2cSAAoJEHZH4aRLwOS6MhsP/A5hs/dxqWYThlIicPP4yDJ2 zTeSaVowWyiXfcYL39Hd+R5tTRoTfF3vMzn7U1d4l6CbbUVn7aZ8nu9LwBnQpEMd qkBGFuIK+LlRB/ChHkNuvsWW8lxjxKxXob2WlxUoKh2PpzXxGLAJTK+STG/oqYkl ZBJIA7YFcm+9d71wCgpQg++7GIwpRqvHA7DaPqs3xZOF4uMY9lbOyJczTRSaBzBA C0R3SivwXqsaW5pXYHhuYb/h0ZfOliDq0eQhGWKYkszYH0coKpo6KCYuWzoqJhkm T5zg0Lp/9R3aCgxe6nAm40kvc1tPB6wgyb09IXd7s/NOFz3MYnAp5Wi4eHcu4mZX 5sLj3urrGD8sYGFsD0Ww/N01RfIeBeUbFTJ2WY4F+cenozHVWISN04uaoA237a9v bFPLNw/HUbHQv9ryfQv8HQpOY/KDrgNaF8X4pW7FpUPlTIlL1a8Su4taCwTsvFXC MvHUHp3NjQ/FOWtxPcFS/InWxbWklsBrx7gnMRqJN0rSdPI+8vOWw9JIvW2yruIX Shg/jw6mrZiVgwsZX2DzNdQ53ClPbf8ub9tLg1Syl351xUJHBHEXPB/bAUUaADH9 /Fuo0z3UbXCXx7g2eZOXTGI/2lvp/cz6AHoCi0oxC3mKAyf8j2FK9S6BRj8gfO67 aKpbl1oGkIzy0UhP0FuC =JpDl -----END PGP SIGNATURE----- --jhQDtFD6/0rlgiNE--