Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752798AbZIOKr7 (ORCPT ); Tue, 15 Sep 2009 06:47:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752295AbZIOKry (ORCPT ); Tue, 15 Sep 2009 06:47:54 -0400 Received: from mail.gmx.net ([213.165.64.20]:36383 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752031AbZIOKrx (ORCPT ); Tue, 15 Sep 2009 06:47:53 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX19hohY7AQphZhqwp2JmpgpPLFkdNqKicphnfaTJoB SB55grL9nayAnU Subject: Re: More BFS benchmarks and scheduler issues From: Mike Galbraith To: Jason Garrett-Glaser Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar In-Reply-To: <28f2fcbc0909141529n4ee32d6t47ca8bdaf02dad@mail.gmail.com> References: <28f2fcbc0909141529n4ee32d6t47ca8bdaf02dad@mail.gmail.com> Content-Type: text/plain Date: Tue, 15 Sep 2009 12:47:47 +0200 Message-Id: <1253011667.9128.16.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.47 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2871 Lines: 79 On Mon, 2009-09-14 at 15:29 -0700, Jason Garrett-Glaser wrote: > As an x264 developer, I have no position on the whole debate over > BFS/CFS (nor am I a kernel hacker), but a friend of mine recently ran > this set of tests with BFS vs CFS that still doesn't make any sense to > me and suggests some sort of serious suboptimality in the existing > scheduler: Yup, I confirmed your friend's results. > >>>>>>>>>>>>>>>>>> > > Background information necessary to replicate test: > > Input file: http://media.xiph.org/video/derf/y4m/soccer_4cif.y4m > x264 source: git://git.videolan.org/x264.git > revision of x264 used: e553a4c > CPU: Core 2 Quad Q9300 (2.5GHz) > Kernel/distro/platform: 2.6.31 patched with the gentoo patchset, Gentoo, x86_64. > BFS patch: Latest available (BFS 220). > Methodology: Each test was run 3 times. The median of the three was > then selected. > > ./x264/x264 --preset ultrafast --no-scenecut --sync-lookahead 0 --qp > 20 samples/soccer_4cif.y4m -o /dev/null --threads X > BFS CFS > 1: 124.79 fps 131.69 fps > 2: 252.14 fps 192.14 fps > 3: 376.55 fps 223.24 fps > 4: 447.69 fps 242.54 fps > 5: 447.98 fps 252.43 fps > 6: 447.87 fps 253.56 fps > 7: 444.79 fps 250.37 fps > 8: 441.08 fps 251.95 fps After a bit of testing, it turns out that NEXT_BUDDY and LB_BIAS features are _both_ doing injury to this load. We've been looking at NEXT_BUDDY, but LB_BIAS is a new target. Thanks a bunch for the nice repeatable testcase! -Mike x264 --preset ultrafast --no-scenecut --sync-lookahead 0 --qp 20 -o /dev/null --threads $THREADS soccer_4cif.y4m 2.6.32-tip-smp 4 encoded 600 frames, 280.07 fps, 22096.60 kb/s encoded 600 frames, 280.67 fps, 22096.60 kb/s encoded 600 frames, 274.80 fps, 22096.60 kb/s 8 encoded 600 frames, 269.57 fps, 22096.60 kb/s encoded 600 frames, 282.96 fps, 22096.60 kb/s encoded 600 frames, 279.66 fps, 22096.60 kb/s 2.6.31-bfs221-smp 4 encoded 600 frames, 408.38 fps, 22096.60 kb/s encoded 600 frames, 409.17 fps, 22096.60 kb/s encoded 600 frames, 407.50 fps, 22096.60 kb/s 8 encoded 600 frames, 409.82 fps, 22096.60 kb/s encoded 600 frames, 413.00 fps, 22096.60 kb/s encoded 600 frames, 411.10 fps, 22096.60 kb/s test test test... 2.6.32-tip-smp NO_NEXT_BUDDY NO_LB_BIAS 4 encoded 600 frames, 418.07 fps, 22096.60 kb/s encoded 600 frames, 418.72 fps, 22096.60 kb/s encoded 600 frames, 419.10 fps, 22096.60 kb/s 8 encoded 600 frames, 425.75 fps, 22096.60 kb/s encoded 600 frames, 425.45 fps, 22096.60 kb/s encoded 600 frames, 422.49 fps, 22096.60 kb/s -- 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/