Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 29 Sep 2002 10:10:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 29 Sep 2002 10:10:57 -0400 Received: from mail-3.tiscali.it ([195.130.225.149]:22099 "EHLO mail.tiscali.it") by vger.kernel.org with ESMTP id convert rfc822-to-8bit; Sun, 29 Sep 2002 10:10:55 -0400 Content-Type: text/plain; charset="us-ascii" From: Lorenzo Allegrucci Organization: -ENOENT To: Linux Kernel Subject: qsbench, interesting results Date: Sun, 29 Sep 2002 16:15:24 +0200 User-Agent: KMail/1.4.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Message-Id: <200209291615.24158.l.allegrucci@tiscalinet.it> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2727 Lines: 71 qsbench is a VM benchmark based on sorting a large array by quick sort. http://web.tiscali.it/allegrucci/qsbench-1.0.0.tar.gz Below are some results of qsbench sorting a 350Mb array on a 256+400Mb RAM+swap machine. Tested kernels: 2.4.19, 2.5.38 and 2.5.39 All runs made with the same default seed, to compare apples with apples :) I used /usr/bin/time because it gives better statistics such as major and minor page faults etc. (Sorry for >72 cols). 2.4.19 bash-2.05# /usr/bin/time ./qsbench -m 350 46.29user 3.54system 2:34.66elapsed 32%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (24739major+370199minor)pagefaults 0swaps bash-2.05# /usr/bin/time ./qsbench -m 350 46.57user 3.27system 2:35.73elapsed 32%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (24493major+370706minor)pagefaults 0swaps bash-2.05# /usr/bin/time ./qsbench -m 350 46.61user 3.09system 2:35.91elapsed 31%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (24560major+370571minor)pagefaults 0swaps Perfectly reproducible performance. 2.5.38 bash-2.05# /usr/bin/time ./qsbench -m 350 ERROR: i = 7766682 *** WARNING *** 1 errors. 47.11user 3.57system 3:42.19elapsed 22%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (39875major+439626minor)pagefaults 0swaps bash-2.05# /usr/bin/time ./qsbench -m 350 46.80user 3.68system 3:42.20elapsed 22%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (39336major+441350minor)pagefaults 0swaps bash-2.05# /usr/bin/time ./qsbench -m 350 46.87user 3.70system 3:44.50elapsed 22%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (39926major+440091minor)pagefaults 0swaps This is interesting, qsbench got an array not "quite" sorted. I have run qsbench a lot of times in the past on many kernels and I have never seen such error. I don't think it's my hardware fault so I would like to know if somebody can reproduce it. Performance is worse than 2.4.19 2.5.39 bash-2.05# /usr/bin/time ./qsbench -m 350 46.94user 4.41system 8:17.94elapsed 10%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (66343major+455167minor)pagefaults 0swaps bash-2.05# /usr/bin/time ./qsbench -m 350 46.74user 4.64system 8:45.03elapsed 9%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (68600major+454782minor)pagefaults 0swaps bash-2.05# /usr/bin/time ./qsbench -m 350 46.81user 4.31system 8:37.07elapsed 9%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (69090major+454355minor)pagefaults 0swaps Big performance drop. Comments? - 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/