Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 13 Jan 2002 10:25:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 13 Jan 2002 10:24:11 -0500 Received: from lilly.ping.de ([62.72.90.2]:34054 "HELO lilly.ping.de") by vger.kernel.org with SMTP id ; Sun, 13 Jan 2002 10:23:55 -0500 Date: 13 Jan 2002 16:15:37 +0100 Message-ID: <20020113161537.A1439@planetzork.spacenet> From: jogi@planetzork.ping.de To: "Andrea Arcangeli" Cc: "Robert Love" , "Alan Cox" , nigel@nrg.org, "Rob Landley" , "Andrew Morton" , linux-kernel@vger.kernel.org Subject: Re: [2.4.17/18pre] VM and swap - it's really unusable In-Reply-To: <1010781207.819.27.camel@phantasy> <20020112121315.B1482@inspiron.school.suse.de> <20020112160714.A10847@planetzork.spacenet> <20020112170528.N1482@inspiron.school.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.15i In-Reply-To: <20020112170528.N1482@inspiron.school.suse.de>; from andrea@suse.de on Sat, Jan 12, 2002 at 05:05:28PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 12, 2002 at 05:05:28PM +0100, Andrea Arcangeli wrote: > On Sat, Jan 12, 2002 at 04:07:14PM +0100, jogi@planetzork.ping.de wrote: [...] > > Hello Andrea, > > > > I did my usual compile testings (untar kernel archive, apply patches, > > make -j ... > > > > Here are some results (Wall time + Percent cpu) for each of the consecutive five runs: > > > > 13-pre5aa1 18-pre2aa2 18-pre3 18-pre3s 18-pre3sp > > j100: 6:59.79 78% 7:07.62 76% * 6:39.55 81% 6:24.79 83% > > j100: 7:03.39 77% 8:10.04 66% * 8:07.13 66% 6:21.23 83% > > j100: 6:40.40 81% 7:43.15 70% * 6:37.46 81% 6:03.68 87% > > j100: 7:45.12 70% 7:11.59 75% * 7:14.46 74% 6:06.98 87% > > j100: 6:56.71 79% 7:36.12 71% * 6:26.59 83% 6:11.30 86% > > > > j75: 6:22.33 85% 6:42.50 81% 6:48.83 80% 6:01.61 89% 5:42.66 93% > > j75: 6:41.47 81% 7:19.79 74% 6:49.43 79% 5:59.82 89% 6:00.83 88% > > j75: 6:10.32 88% 6:44.98 80% 7:01.01 77% 6:02.99 88% 5:48.00 91% > > j75: 6:28.55 84% 6:44.21 80% 9:33.78 57% 6:19.83 85% 5:49.07 91% > > j75: 6:17.15 86% 6:46.58 80% 7:24.52 73% 6:23.50 84% 5:58.06 88% > > > > * build incomplete (OOM killer killed several cc1 ... ) > > > > So far 2.4.13-pre5aa1 had been the king of the block in compile times. > > But this has changed. Now the (by far) fastest kernel is 2.4.18-pre > > + Ingos scheduler patch (s) + preemptive patch (p). I did not test > > preemptive patch alone so far since I don't know if the one I have > > applies cleanly against -pre3 without Ingos patch. I used the > > following patches: > > > > s: sched-O1-2.4.17-H6.patch > > p: preempt-kernel-rml-2.4.18-pre3-ingo-1.patch > > > > I hope this info is useful to someone. > > the improvement of "sp" compared to "s" is quite visible, not sure how > can a little different time spent in kernel make such a difference on > the final numbers, also given compilation is mostly an userspace task, I > assume you were swapping out or running out of cache at the very least, > right? The system is *heavily* swapping. Plain 2.4.18-pre3 can not even finish the jobs because it runs out of memory. That's why I used j75 or j100 initially. Otherwise there was not even a difference between the 2.4.10+ vm and the 2.4.9-ac+ vm. All I want to test with this "benchmark" is how well the system reacts when I throw *lots* of compilation jobs at it ... > btw, I'd be curious if you could repeat the same test with -j1 or -j2? > (actually real world) Using just -j1 or -j2 will probably be no difference (I will test it anyway and post the results). > Still the other numbers remains interesting for a trashing machine, but > a few percent difference with a trashing box isn't a big difference, vm > changes can infulence those numbers more than any preempt or scheduler > number (of course if my guess that you're swapping out is really right :). > I guess "p" helps because we simply miss some schedule point in some vm > routine. Hints? But what *I* like most about the preemptive results are that the results for all runs do not vary that much. Looking at plain 2.4.18-pre3 there is a huge difference in runtime between the fastest and the longest run. Regards, Jogi -- Well, yeah ... I suppose there's no point in getting greedy, is there? << Calvin & Hobbes >> - 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/