From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753130AbXCMFLL (ORCPT ); Tue, 13 Mar 2007 01:11:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753127AbXCMFLL (ORCPT ); Tue, 13 Mar 2007 01:11:11 -0400 Received: from smtp102.plus.mail.mud.yahoo.com ([68.142.206.235]:45172 "HELO smtp102.plus.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753130AbXCMFLH (ORCPT ); Tue, 13 Mar 2007 01:11:07 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=AnYBQ0BvMKu0qipTMLW2V4yNcS2h0IcFChzKYlGKyoVFY6rTfQVJD5kjqOAKjIn0f7WU0P8En3vhKmPGtVqRwB/uU/rAQBtQpmFqotJ5D1xLCACQ/bMr542H1yAwDbgy+dmOehdJPoabkp90yQOzukKisrNI09hLHb1ektSWUdI= ; X-YMail-OSG: ryZd7_0VM1k0lT9dORqWHzdaZxk8ZHx9CS.hTDw.uQ6gvh5732VutNkCmh6xi691U9MIrjnNQ52HQsB0RbV7OXtGMhnHYKTVBsiPZR.dh7CcHCjsekJg6PUPkU4gdtaBFj9e4u0B2t9rMGE- Message-ID: <45F63266.1080509@yahoo.com.au> Date: Tue, 13 Mar 2007 16:11:02 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Anton Blanchard CC: Rik van Riel , Lorenzo Allegrucci , linux-kernel@vger.kernel.org, Ingo Molnar , Suparna Bhattacharya , Jens Axboe Subject: Re: SMP performance degradation with sysbench References: <1172425476.5489.11.camel@odyssey.lan> <45E21FEC.9060605@redhat.com> <45E2E244.8040009@yahoo.com.au> <20070312220042.GA807@kryten> In-Reply-To: <20070312220042.GA807@kryten> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Anton Blanchard wrote: > > Hi Nick, > > >>Anyway, I'll keep experimenting. If anyone from MySQL wants to help look >>at this, send me a mail (eg. especially with the sched_setscheduler issue, >>you might be able to do something better). > > > I took a look at this today and figured Id document it: > > http://ozlabs.org/~anton/linux/sysbench/ > > Bottom line: it looks like issues in the glibc malloc library, replacing > it with the google malloc library fixes the negative scaling: > > # apt-get install libgoogle-perftools0 > # LD_PRELOAD=/usr/lib/libtcmalloc.so /usr/sbin/mysqld Hi Anton, Very cool. Yeah I had come to the conclusion that it wasn't a kernel issue, and basically was afraid to look into userspace ;) That bogus setscheduler thing must surely have never worked, though. I wonder if FreeBSD avoids the scalability issue because it is using SCHED_RR there, or because it has a decent threaded malloc implementation. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com