From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753315AbcLNFP3 (ORCPT ); Wed, 14 Dec 2016 00:15:29 -0500 Received: from mail-wj0-f176.google.com ([209.85.210.176]:36461 "EHLO mail-wj0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750791AbcLNFP2 (ORCPT ); Wed, 14 Dec 2016 00:15:28 -0500 MIME-Version: 1.0 In-Reply-To: <20161213134054.GU3207@twins.programming.kicks-ass.net> References: <20161213134054.GU3207@twins.programming.kicks-ass.net> From: =?UTF-8?Q?Alexandre=2DXavier_Labont=C3=A9=2DLamoureux?= Date: Wed, 14 Dec 2016 00:15:25 -0500 Message-ID: Subject: Re: Scheduler patches: 6x performance increase when system is under heavy load To: Peter Zijlstra , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id uBE5FaIj027444 > Which of the 4 patches does this? I used all the 4 patches at the same time. Each patch fixes a different bug. Would you like me to try each of them individually? Were you already aware of each of these bugs? > Also, what hypervisor are you using and what does the output of booting > with "sched_debug" look like? I was running the distro in VirualBox on Fedora. Here's the info from /proc/sched_debug: https://justpaste.it/11dhb dmesg: https://justpaste.it/11dhr > Lastly, can you reproduce on real hardware? No. On real hardware, I tested in Ubuntu on an i7-4790 3.60GHz CPU without disabling HT and I saw no difference between CFS, the patched kernel and MuQSS. If I get to know a reason why one would be better than the other, I'd take the time to test it on more hardware. I'm curious how I got such a performance improvement in my VM. On Tue, Dec 13, 2016 at 8:40 AM, Peter Zijlstra wrote: > On Sun, Dec 11, 2016 at 04:41:51PM -0500, Alexandre-Xavier Labonté-Lamoureux wrote: >> >> Here are my results (using "time make -j32" on my VM that has 4 cores): >> >> Kernel 4.8.14 >> real 26m56.151s >> user 79m52.472s >> sys 7m42.964s >> >> Same kernel, but patched: >> real 4m25.238s >> user 13m52.932s >> sys 1m25.820s >> >> I hope you guys will look into this. > > Which of the 4 patches does this? > > Also, what hypervisor are you using and what does the output of booting > with "sched_debug" look like? > > Lastly, can you reproduce on real hardware?