From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752368AbZIIKSA (ORCPT ); Wed, 9 Sep 2009 06:18:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752035AbZIIKR7 (ORCPT ); Wed, 9 Sep 2009 06:17:59 -0400 Received: from mail-in-16.arcor-online.net ([151.189.21.56]:55630 "EHLO mail-in-16.arcor-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525AbZIIKR6 (ORCPT ); Wed, 9 Sep 2009 06:17:58 -0400 X-DKIM: Sendmail DKIM Filter v2.8.2 mail-in-04.arcor-online.net 5202B33AA81 Message-ID: <4AA780D7.7040609@arcor.de> Date: Wed, 09 Sep 2009 13:17:59 +0300 From: Nikos Chantziaras Organization: Lucas Barks User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090826 Thunderbird/3.0b3 MIME-Version: 1.0 To: Peter Zijlstra CC: Mike Galbraith , Ingo Molnar , Jens Axboe , Con Kolivas , linux-kernel@vger.kernel.org Subject: Re: BFS vs. mainline scheduler benchmarks and measurements References: <20090906205952.GA6516@elte.hu> <20090907094953.GP18599@kernel.dk> <20090907115750.GW18599@kernel.dk> <20090907141458.GD24507@elte.hu> <20090907173846.GB18599@kernel.dk> <20090907204458.GJ18599@kernel.dk> <20090908091304.GQ18599@kernel.dk> <1252423398.7746.97.camel@twins> <20090908203409.GJ18599@kernel.dk> <20090909061308.GA28109@elte.hu> <1252486344.28645.18.camel@marge.simson.net> <4AA76FD2.1050103@arcor.de> <1252487869.7746.181.camel@twins> <4AA7780A.3000008@arcor.de> In-Reply-To: <4AA7780A.3000008@arcor.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/09/2009 12:40 PM, Nikos Chantziaras wrote: > On 09/09/2009 12:17 PM, Peter Zijlstra wrote: >> On Wed, 2009-09-09 at 12:05 +0300, Nikos Chantziaras wrote: >> >>> Thank you for mentioning min_granularity. After: >>> >>> echo 10000000> /proc/sys/kernel/sched_latency_ns >>> echo 2000000> /proc/sys/kernel/sched_min_granularity_ns >> >> You might also want to do: >> >> echo 2000000> /proc/sys/kernel/sched_wakeup_granularity_ns >> >> That affects when a newly woken task will preempt an already running >> task. > > Lowering wakeup_granularity seems to make things worse in an interesting > way: > > With low wakeup_granularity, the video itself will start skipping if I > move the window around. However, the window manager's effect of moving a > window around is smooth. > > With high wakeup_granularity, the video itself will not skip while > moving the window around. But this time, the window manager's effect of > the window move is skippy. > > (I should point out that only with the BFS-patched kernel can I have a > smooth video *and* a smooth window-moving effect at the same time.) > Mainline seems to prioritize one of the two according to whether > wakeup_granularity is raised or lowered. However, I have not tested > Mike's patch yet (but will do so ASAP.) I've tested Mike's patch and it achieves the same effect as raising sched_min_granularity. To round it up: By testing various values for sched_latency_ns, sched_min_granularity_ns and sched_wakeup_granularity_ns, I can achieve three results: 1. Fluid animations for the foreground app, skippy ones for the rest (video plays nicely, rest of the desktop lags.) 2. Fluid animations for the background apps, a skippy one for the one in the foreground (dekstop behaves nicely, video lags.) 3. Equally skippy/jerky behavior for all of them. Unfortunately, a "4. Equally fluid behavior for all of them" cannot be achieved with mainline, unless I missed some other tweak.