From owner-cvs-src@FreeBSD.ORG Mon Jun 14 18:57:11 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6697716A4CE for ; Mon, 14 Jun 2004 18:57:11 +0000 (GMT) Received: from mail5.speakeasy.net (mail5.speakeasy.net [216.254.0.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2E6B943D39 for ; Mon, 14 Jun 2004 18:57:11 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 9866 invoked from network); 14 Jun 2004 18:57:10 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 14 Jun 2004 18:57:10 -0000 Received: from 10.50.41.233 (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id i5EIv7GY058232; Mon, 14 Jun 2004 14:57:07 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Robert Watson Date: Mon, 14 Jun 2004 14:58:02 -0400 User-Agent: KMail/1.6 References: In-Reply-To: MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200406141458.02468.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org cc: "David E. O'Brien" Subject: Re: cvs commit: src/sys/amd64/conf GENERIC X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Jun 2004 18:57:11 -0000 On Monday 14 June 2004 02:21 pm, Robert Watson wrote: > On Mon, 14 Jun 2004, John Baldwin wrote: > > On Sunday 13 June 2004 07:03 pm, David E. O'Brien wrote: > > > obrien 2004-06-13 23:03:57 UTC > > > > > > FreeBSD src repository > > > > > > Modified files: > > > sys/amd64/conf GENERIC > > > Log: > > > The majority of FreeBSD/amd64 machines are SMP, so use > > > ADAPTIVE_MUTEXES by default to improve performance. > > > > We don't know if it improves performance yet. :) > > Yeah, as I was mentioning to David over the weekend, it's believed to help > performance anecdotally in a number of interesting cases, and if we can > show it helps in a majority of interesting cases (and doesn't > substantially hurt the others) then I think this should actually be in > GENERIC across all platforms, not just amd64. I also found I > misunderstood his commit message as it seems to suggest it helps SMP at > the cost of UP, but in fact does not say that. > > Kris reported that he experienced some apparent hangs related to running > with ADAPTIVE_MUTEXES and we should resolve if it was actually the cause > or whether it just triggered an existing race. I'm betting it is just triggering a race. When I first did the adaptive mutexes I stress tested it (-j buildworld loops) on an ultra60, an alpha ds20, and a quad pii-xeon w/o any lockups. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org