Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965066AbcJaPHw (ORCPT ); Mon, 31 Oct 2016 11:07:52 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:40306 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964999AbcJaPHs (ORCPT ); Mon, 31 Oct 2016 11:07:48 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 31 Oct 2016 08:07:46 -0700 From: Vikram Mulukutla To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Srivatsa Vaddagiri , Steve Muckle , Olav Haugan , Syed Rameez Mustafa , Joonwoo Park , Pavankumar Kondeti , Saravana Kannan , Bryan Huntsman , Juri Lelli , Morten Rasmussen , Dietmar Eggemann , Chris Redpath , Robin Randhawa , Patrick Bellasi , Todd Kjos , Srinath Sridharan , Andres Oportus , Leo Yan , Vincent Guittot , Vikram Mulukutla Subject: Re: [RFC PATCH 0/3] sched: Introduce Window Assisted Load Tracking In-Reply-To: <20161028084945.GX3102@twins.programming.kicks-ass.net> References: <1477638642-17428-1-git-send-email-markivx@codeaurora.org> <20161028074953.GU3102@twins.programming.kicks-ass.net> <9ac6a40a330b82e424dc2f56ea7fd976@codeaurora.org> <20161028084945.GX3102@twins.programming.kicks-ass.net> Message-ID: <44f202093ea289c45a5a2710a2787831@codeaurora.org> User-Agent: Roundcube Webmail/1.2.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2914 Lines: 59 On 2016-10-28 01:49, Peter Zijlstra wrote: > On Fri, Oct 28, 2016 at 12:57:05AM -0700, Vikram Mulukutla wrote: >> On 2016-10-28 00:49, Peter Zijlstra wrote: >> >On Fri, Oct 28, 2016 at 12:10:39AM -0700, Vikram Mulukutla wrote: >> >>This RFC patch has been tested on live X86 machines with the following >> >>sanity >> >>and benchmark results (thanks to Juri Lelli, Dietmar Eggeman, Patrick >> >>Bellasi >> >>for initial code reviews): >> >> >> >>(Tested on an Intel i7 2nd generation CPU, 8GB RAM, Nvidia GTX950Ti >> >>graphics, >> >>with the same frequency list as above. Running Ubuntu 16.04 on a v4.8.2 >> >>baseline. WALT window size was 10ms. Only deltas above 3% are considered >> >>non-noise.Power measured with Intel RAPL counters) >> > >> >Was this comparison done using the use_walt_metric sysctl knob? >> >> Yes, it was. You will want to see numbers against a pure 4.8.2 without >> any >> of the WALT code, correct? > > Yep, because with the sysctl we still run all the accounting code. So > esp things like the hackbench run are meaningless (note that even the > CONFIG thing doesn't take out everything). > > Also, I think it makes sense to always (also) compare against the > "performance" governor. That way you can see the drop in absolute > performance etc.. Ok, here are some numbers. I should be able to get the rest during the week. The averages are pretty close, so I figured I would include some percentile numbers. PELT and WALT numbers are with schedutil. On average it seems we're introducing about 0.5% overhead with the current additional accounting. Test: perf bench sched messaging -g 50 -l 5000 +-------------+-------------+----------+----------+-----------+ | 4.8.2-walt | Performance | Ondemand | PELT | WALT(10ms)| +-------------+-------------+----------+----------+---------- + | | | | | | | 90th | 17.077 | 17.088 | 17.088 | 17.159 | | | | | | | | 96th | 17.117 | 17.421 | 17.198 | 17.343 | | | | | | | | Average | 16.910 | 16.916 | 16.937 | 16.962 | | | | | | | +-------------+-------------+----------+----------+-----------+ | 4.8.2-raw | Performance | Ondemand | PELT | WALT(10ms)| +-------------+-------------+----------+----------+-----------+ | | | | | | | 90th | 16.919 | 17.1694 | 16.986 | 0 | | | | | | | | 96th | 16.980 | 17.364 | 17.052 | 0 | | | | | | | | Average | 16.841 | 16.902 | 16.860 | 0 | +-------------+-------------+----------+----------+-----------+