From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753354AbaGBMt3 (ORCPT ); Wed, 2 Jul 2014 08:49:29 -0400 Received: from casper.infradead.org ([85.118.1.10]:60638 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753255AbaGBMt2 (ORCPT ); Wed, 2 Jul 2014 08:49:28 -0400 Date: Wed, 2 Jul 2014 14:49:18 +0200 From: Peter Zijlstra To: Michael wang Cc: Mike Galbraith , Rik van Riel , Ingo Molnar , Alex Shi , Paul Turner , Mel Gorman , Daniel Lezcano , LKML Subject: Re: [PATCH] sched: select 'idle' cfs_rq per task-group to prevent tg-internal imbalance Message-ID: <20140702124918.GE19379@twins.programming.kicks-ass.net> References: <53A11A89.5000602@linux.vnet.ibm.com> <20140623094251.GS19860@laptop.programming.kicks-ass.net> <53A8F1DE.2060908@linux.vnet.ibm.com> <20140701082020.GL6758@twins.programming.kicks-ass.net> <53B273A2.5050500@linux.vnet.ibm.com> <20140701085658.GM6758@twins.programming.kicks-ass.net> <53B372C6.5000107@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="N1GIdlSm9i+YlY4t" Content-Disposition: inline In-Reply-To: <53B372C6.5000107@linux.vnet.ibm.com> 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 --N1GIdlSm9i+YlY4t Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 02, 2014 at 10:47:34AM +0800, Michael wang wrote: > The opinion on features actually make me a little confusing... I used to > think the scheduler is willing on providing kinds of way to adapt itself > to different situation, and some features do help on that, make them > only a debug option make the scheduler more static to users, but I know > that's not what I should touched... >=20 > Anyway, the problem is still there and seems like we have to adopt some > optional solution to address it, we'll still working and practice on > that, please let us know if you have any ideas we could help on ;-) No, its very much not intended as a user knob to adapt. The problem with that approach to scheduling is that one set of knobs runs workload A, while another set of knobs runs workload B, but what happens if you need to run both A and B on the same machine? So optional things and knobs are a complete fail and will not happen. Clearly I need to go take out all these things because people don't seem to know this and SCHED_DEBUG isn't a big enough hint. Tedious. --N1GIdlSm9i+YlY4t Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTs//OAAoJEHZH4aRLwOS6pD8P/39iviJIUNlR2adHta1DCSY9 1efcFK466GQWg7lnb0fSOaseOec04NYJfbmymEQZSp8AmOELuBshjtdaeiCzDQkc hc6lrE2xROMRPDf5eZqSfNVdJZo45mzoK6Mxid6EPl0rsso9/thBdyMLgqjME+vZ CpT94lk4GOzxDSLgvoa2Dy8jLeKpGAqqhoWXHmMkQtzj+Ls0AENhzQsUmge0Qkti b+DM3vpikdEPMP8Rs1NcO1e0YKL+hfGBf+g9fkFOv6Dzq2hzk7SYY1yTLYZlNx8K vqYuQ5JCPcdYMhGD8cpvQHXQuFdtmTzrmpyn2yzBqMB8Is2ycAQopPOuoAVEg4kp 70Np4T6Dj0r4g3dWK/xxhQ9iW6Rn7gUorxnfNXTjdlXC072/pX7gvCV6cADSVLMn xPRNtzaIh5bQG6sBZD2TcXaKjxxbWTo7bistPJADHar2n9tLvRwHtL7Q0zAhzzCS lXhl0dNtd3fkJXyWuH6JNv1Md03niES0cJM73cQ1reS1JwlHephm5fwRzr1cnsN4 OtgthwjratWeBk/wsVaEPtVpS/46LjHo/bdp90Y3G03AAkU7P3PL15W7t4ItZ/ZE FyfrVSNaYwsRCJCWnVuqtY1+a3SNYgudxFl2PX6Sq/ptkAf1Czs7UqLWwP8QsCu+ Eh655+YygKy/+SR6XG55 =Rb9c -----END PGP SIGNATURE----- --N1GIdlSm9i+YlY4t--