Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263403AbTH0OnS (ORCPT ); Wed, 27 Aug 2003 10:43:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263410AbTH0OnR (ORCPT ); Wed, 27 Aug 2003 10:43:17 -0400 Received: from inway106.cdi.cz ([213.151.81.106]:8321 "EHLO luxik.cdi.cz") by vger.kernel.org with ESMTP id S263403AbTH0OnP (ORCPT ); Wed, 27 Aug 2003 10:43:15 -0400 Date: Wed, 27 Aug 2003 16:42:56 +0200 (CEST) From: devik X-X-Sender: To: Subject: Re: 2.4.21 on SMP has extra slow context switch In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1412 Lines: 50 New informations. I tested more kernels. 2.4.21 and 22 with 2 CPUs are slow as hell. When I reboot with maxcpus=1 then all is suddenly ok. Also floppy drive was not detected in 2 CPU config while with maxcpus=1 it is. I placed lmbench data and dmesg output to http://luxik.cdi.cz/~devik/tmp/slow-smp/ in case someone knows what to do. I can do some other tests if you want me to do them. thanks, devik On Wed, 27 Aug 2003, devik wrote: > Hello, > > I upgraded one SMP box (Soyo MB, 2x PII/350, 500MB) from > 2.4.8 (really) to 2.4.21 last week. Users start to complaint > that it is slow. > I run lmbench's context switch measurer and it's result is: > "size=0k ovr=5.41 > 2 169.26 > 3 111.28 > 4 83.99 > > While on very similar UP system (the same CPU & kernel) it is: > "size=0k ovr=3.50 > 2 1.80 > 3 2.08 > 4 2.89 > > Have someone even idea what is going on ? The systems seems to be > fairly stable but slooow. > I plan to reboot with single CPU at evening and/or upgrade to .22, > but the numbers above are weird. > > thanks, > ------------------------------- > Martin Devera aka devik > Linux kernel QoS/HTB maintainer > http://luxik.cdi.cz/~devik/ > > - 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/