From owner-freebsd-threads@FreeBSD.ORG Sun May 23 12:56:29 2004 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 747AF16A4CE for ; Sun, 23 May 2004 12:56:29 -0700 (PDT) Received: from sccrmhc11.comcast.net (sccrmhc11.comcast.net [204.127.202.55]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6AFB343D1F for ; Sun, 23 May 2004 12:56:25 -0700 (PDT) (envelope-from julian@elischer.org) Received: from interjet.elischer.org ([24.7.73.28]) by comcast.net (sccrmhc11) with ESMTP id <2004052319562001100lhe4ae>; Sun, 23 May 2004 19:56:21 +0000 Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id MAA13983; Sun, 23 May 2004 12:56:18 -0700 (PDT) Date: Sun, 23 May 2004 12:56:17 -0700 (PDT) From: Julian Elischer To: JG In-Reply-To: <5.2.0.9.2.20040523122839.01597388@mail.ojoink.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-threads@freebsd.org Subject: Re: Why is MySQL nearly twice as fast on Linux? X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 May 2004 19:56:29 -0000 On Sun, 23 May 2004, JG wrote: > > > > >once again, here's the deal. > > > >i'm willing to PAY someone to own this issue and figure out how to resolve > >it. also give them access to my box to do whatever they feel like (it > >needs to stay AMD64 - but i don't care if you go up to 5.3, down to > >5.2-current, 5.1, whatever) > > > >so i'm supplying resources and incentive. why is nobody stepping up to the > >plate to help figure out where the bottleneck is? it *sounds* like it's > >threading or the scheduler or a combination of both, i don't know. > > > >but i'm pledging at least $250 USD, and someone else will pledge another > >$100 - and that's just two of us. > > > >if someone owns it and can get a fix out in the next week or two (i don't > >care how or where) i could even give a bonus. > > > >once again - resources and incentive. let's figure this out so everyone > >can benefit. i just want to expedite this effort. > > I'm the other $100 sponsor on this offer.... Mike sort of jumped the gun here, > but let me add that we want to see FreeBSD within +/- 10% performance Vs. > "Stock" > Linux results with a comparable or equivalent my.cnf files > > If it's possible, we'll pay to have it happen. There are two things that may help pinpoint the problem firstly, you might try run some work under truss or ktrace and get a feel for the times that various operations take. you might also lile to run a profiled app and a profiled kernel and use gprof and kgmon to get results. There is obviously a bottleneck, but it's very hard to tell what it is.. My guess is that the scheduler(s) are not doing a very good job. and the fact that GIANT is not removed from the kernel yet says that generally syscalls will be a bottleneck. ULE should be able to do a better job at scheduling with multiple CPUs but it is a work in progress. If threads all hit a GIANT based logjam, there is not a lot the scheduler can do about it..