Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751816AbbGFOfS (ORCPT ); Mon, 6 Jul 2015 10:35:18 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:55791 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751015AbbGFOfO (ORCPT ); Mon, 6 Jul 2015 10:35:14 -0400 Message-ID: <559A91F4.7000903@fb.com> Date: Mon, 6 Jul 2015 10:34:28 -0400 From: Josef Bacik User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Mike Galbraith CC: Peter Zijlstra , , , , , kernel-team Subject: Re: [PATCH RESEND] sched: prefer an idle cpu vs an idle sibling for BALANCE_WAKE References: <1432761736-22093-1-git-send-email-jbacik@fb.com> <20150528102127.GD3644@twins.programming.kicks-ass.net> <20150528110514.GR18673@twins.programming.kicks-ass.net> <1434087305.3674.26.camel@gmail.com> <5581B70D.2000800@fb.com> <1434588939.3444.25.camel@gmail.com> <55823F33.7040005@fb.com> <1434600765.3393.9.camel@gmail.com> <55957871.7080906@fb.com> <1435905658.6418.52.camel@gmail.com> <1436025462.17152.37.camel@gmail.com> <1436080661.22930.22.camel@gmail.com> <1436159590.5850.27.camel@gmail.com> In-Reply-To: <1436159590.5850.27.camel@gmail.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-07-06_07:2015-07-06,2015-07-06,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2192 Lines: 55 On 07/06/2015 01:13 AM, Mike Galbraith wrote: > Hm. Piddling with pgbench, which doesn't seem to collapse into a > quivering heap when load exceeds cores these days, deltas weren't all > that impressive, but it does appreciate the extra effort a bit, and a > bit more when clients receive it as well. > > If you test, and have time to piddle, you could try letting wake_wide() > return 1 + sched_feat(WAKE_WIDE_IDLE) instead of adding only if wakee is > the dispatcher. > > Numbers from my little desktop box. > > NO_WAKE_WIDE_IDLE > postgres@homer:~> pgbench.sh > clients 8 tps = 116697.697662 > clients 12 tps = 115160.230523 > clients 16 tps = 115569.804548 > clients 20 tps = 117879.230514 > clients 24 tps = 118281.753040 > clients 28 tps = 116974.796627 > clients 32 tps = 119082.163998 avg 117092.239 1.000 > > WAKE_WIDE_IDLE > postgres@homer:~> pgbench.sh > clients 8 tps = 124351.735754 > clients 12 tps = 124419.673135 > clients 16 tps = 125050.716498 > clients 20 tps = 124813.042352 > clients 24 tps = 126047.442307 > clients 28 tps = 125373.719401 > clients 32 tps = 126711.243383 avg 125252.510 1.069 1.000 > > WAKE_WIDE_IDLE (clients as well as server) > postgres@homer:~> pgbench.sh > clients 8 tps = 130539.795246 > clients 12 tps = 128984.648554 > clients 16 tps = 130564.386447 > clients 20 tps = 129149.693118 > clients 24 tps = 130211.119780 > clients 28 tps = 130325.355433 > clients 32 tps = 129585.656963 avg 129908.665 1.109 1.037 > I have time for twiddling, we're carrying ye olde WAKE_IDLE until we get this solved upstream and then I'll rip out the old and put in the new, I'm happy to screw around until we're all happy. I'll throw this in a kernel this morning and run stuff today. Barring any issues with the testing infrastructure I should have results today. Thanks, Josef -- 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/