Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752656AbZAFJb5 (ORCPT ); Tue, 6 Jan 2009 04:31:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751189AbZAFJbs (ORCPT ); Tue, 6 Jan 2009 04:31:48 -0500 Received: from mail.gmx.net ([213.165.64.20]:57803 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751164AbZAFJbr (ORCPT ); Tue, 6 Jan 2009 04:31:47 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX19JIs8n31BJapo5AtTW1iSdb5zhP7v6oUtnFkY+xC 9ZiLHCYSsYoiL4 Subject: Re: [PATCH v7 0/8] Tunable sched_mc_power_savings=n From: Mike Galbraith To: svaidy@linux.vnet.ibm.com Cc: Ingo Molnar , Balbir Singh , linux-kernel@vger.kernel.org, Peter Zijlstra , Andrew Morton In-Reply-To: <1231168786.9120.26.camel@marge.simson.net> References: <20081230062139.GA30038@elte.hu> <20081230180722.GA29060@dirshya.in.ibm.com> <20090102072600.GA13412@dirshya.in.ibm.com> <20090102221630.GF17240@elte.hu> <1230967765.5257.6.camel@marge.simson.net> <20090103101626.GA4301@dirshya.in.ibm.com> <1230981761.27180.10.camel@marge.simson.net> <1231081200.17224.44.camel@marge.simson.net> <20090104181946.GC4301@dirshya.in.ibm.com> <1231098769.5757.43.camel@marge.simson.net> <20090105032029.GE4301@dirshya.in.ibm.com> <1231130416.5479.8.camel@marge.simson.net> <1231137413.10471.23.camel@marge.simson.net> <1231168786.9120.26.camel@marge.simson.net> Content-Type: text/plain Date: Tue, 06 Jan 2009 10:31:37 +0100 Message-Id: <1231234297.3806.50.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.58 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1398 Lines: 33 On Mon, 2009-01-05 at 16:19 +0100, Mike Galbraith wrote: > On Mon, 2009-01-05 at 07:37 +0100, Mike Galbraith wrote: > > > I'll rummage around. > > Seems to be about the only thing it could be, load balancing inflicting > injury on very sensitive mysql+oltp pairs. BTW, I verified this. Reverting all load-balancing changes fully restored mysql+oltp peak, and brought mid-range throughput to the same level as sched_mc=2 except at the log-jam end. (haven't looked at vmark, though I'd expect it to be hurting a bit too, it's affinity sensitive as well) I expected sched_mc=2 to help an nfs mount kbuild, and it did, quite a bit. I first tried an nfs4 mount, but after a while, the odd ipv6 80% idle problem came back, so I reverted to nfs3. Full built time there went from 4m25s to 4m2s. A nice improvement. I haven't noticed anything on the interactivity front. Personally, I'd go for sched_mc=2 as default. I value the fork/exec load much more than sensitive benchmarks, though what hurts mysql+oltp will certainly hurt others as well. We have a bit of conflict between keeping CPUs busy and affinity cost. Something to work on. -Mike -- 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/