From owner-freebsd-hackers@FreeBSD.ORG Mon Feb 26 19:52:06 2007 Return-Path: X-Original-To: hackers@freebsd.org Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id BF2B216A400; Mon, 26 Feb 2007 19:52:06 +0000 (UTC) (envelope-from kris@obsecurity.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id AC39613C4B2; Mon, 26 Feb 2007 19:52:06 +0000 (UTC) (envelope-from kris@obsecurity.org) Received: from obsecurity.dyndns.org (elvis.mu.org [192.203.228.196]) by elvis.mu.org (Postfix) with ESMTP id 6582F1A3C19; Mon, 26 Feb 2007 11:52:06 -0800 (PST) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 3DF085138A; Mon, 26 Feb 2007 14:52:05 -0500 (EST) Date: Mon, 26 Feb 2007 14:52:05 -0500 From: Kris Kennaway To: Peter Jeremy Message-ID: <20070226195204.GA14353@xor.obsecurity.org> References: <20070224213111.GB41434@xor.obsecurity.org> <20070226080837.GB844@turion.vk2pj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070226080837.GB844@turion.vk2pj.dyndns.org> User-Agent: Mutt/1.4.2.2i Cc: smp@freebsd.org, hackers@freebsd.org, current@freebsd.org, Kris Kennaway Subject: Re: Progress on scaling of FreeBSD on 8 CPU systems X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Feb 2007 19:52:06 -0000 On Mon, Feb 26, 2007 at 07:08:37PM +1100, Peter Jeremy wrote: > On 2007-Feb-24 16:31:11 -0500, Kris Kennaway wrote: > >We have recently made significant progress on optimizing for MySQL > >running on an 8-core amd64 system. The graph of results may be found > >here: > > > > http://www.freebsd.org/~kris/scaling/scaling.png > > Those results look wonderful. Have you tried increasing the number of > threads to see if there's any nasty knee further to the right? Also, > is there any chance of repeating this testing on one of the big Suns > (or a T2000) to see how this scales to lots of cores? I didnt try at much higher loads yet, that will be interesting to explore. Currently on the Sun T2000 (32 hardware threads = virtual CPUs) we don't have good scaling (it's hard even to saturate all CPUs for kernel workloads): the current thinking is that this is largely because of contention on the global scheduler lock. Even when idle there is a lot of contention on the sched_lock coming from e.g. all 32 CPUs running statclock at once HZ=1000 times a second and fighting for the sched_lock. Fixing this is something Jeff and Attilio are working on (Kip Macy also did a lot of exploratory work last year), so we hope to make further progress over the coming weeks. Kris