Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755583Ab0K2SDz (ORCPT ); Mon, 29 Nov 2010 13:03:55 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:50130 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754631Ab0K2SDy (ORCPT ); Mon, 29 Nov 2010 13:03:54 -0500 Date: Mon, 29 Nov 2010 19:03:24 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: Linus Torvalds , Mike Galbraith , Oleg Nesterov , LKML , Paul Turner Subject: Re: [PATCH v4] sched: automated per session task groups Message-ID: <20101129180324.GA14046@elte.hu> References: <20101121133744.GA10765@elte.hu> <1290700829.4759.16.camel@maggy.simson.net> <1290954299.30515.15.camel@marge.simson.net> <20101128201851.GA20555@elte.hu> <1291031593.32004.19.camel@laptop> <1291052268.32004.171.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1291052268.32004.171.camel@laptop> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1260 Lines: 31 * Peter Zijlstra wrote: > On Mon, 2010-11-29 at 08:27 -0800, Linus Torvalds wrote: > > On Mon, Nov 29, 2010 at 3:53 AM, Peter Zijlstra wrote: > > > > > > Well we totally re-wrote the cgroup load-balancer in -tip. The thing > > > currently in -linus is a utter crap because its very strongly serialized > > > across all cores (some people spend like 25% of their time in there). > > > > Well, it seems that the rewrite is more crap than the "utter crap" in > > current -git. What does that make -tip? Super-utter-crap? > > > > Peter - getting the wrong answer quickly is not any better than strong > > serialization. > > I know, from the testing so far we _thought_ it was fairly sane. > Apparently there's still some work to do. Btw., i think it shows the conceptual power of Mike's patch that this cgroups scheduling suckage was exposed so clearly. Previously it took weeks (sometimes months) for bugs to reach those who are using cgroups. Thanks, Ingo -- 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/