From owner-freebsd-current@FreeBSD.ORG Mon Aug 23 18:51:16 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 03A9016A4CE for ; Mon, 23 Aug 2004 18:51:16 +0000 (GMT) Received: from mail5.speakeasy.net (mail5.speakeasy.net [216.254.0.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id D4D6643D58 for ; Mon, 23 Aug 2004 18:51:15 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 24495 invoked from network); 23 Aug 2004 18:51:12 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 23 Aug 2004 18:51:11 -0000 Received: from [10.50.40.208] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id i7NIoexd088437; Mon, 23 Aug 2004 14:50:41 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: freebsd-current@FreeBSD.org Date: Mon, 23 Aug 2004 14:16:25 -0400 User-Agent: KMail/1.6.2 References: <20040822115345.Y94593@carver.gumbysoft.com> In-Reply-To: <20040822115345.Y94593@carver.gumbysoft.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200408231416.25464.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx Subject: Re: PLEASE TEST: IPI deadlock avoidance patch X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Aug 2004 18:51:16 -0000 On Sunday 22 August 2004 03:05 pm, Doug White wrote: > Hey folks, > > If you have a reasonably fast i386 or amd64 multiprocessor and/or > hyperthreading machine and are experiencing reproducible hangs during -j > buildwords and other highly parallel operations, please try this patch: > > http://people.freebsd.org/~dwhite/smp_rv_mtx.patch > > This patch avoids a deadlock between the smp_rendezvous() mechanism and > TLB shootdowns via pmap by forcing them to share a mutex. The patch has > been tested on several multiproc Xeon systems and a dual Opteron I have > here and is stable, but a couple of more eyeballs and varied loads > wouldn't hurt since this will be going into RELENG_5. > > If there's anything glaringly wrong from a style point of view, let me > know too. > > I plan on committing this late Monday or Tuesday, barring any serious > problems. > > Thanks to alc for the nudge on the solution and rwatson for staying up > late and testing it on his hardware. Looks good to me. I also think this might help the KSE + SMP hangs. Only suggestion I might have is to rename smp_rv_mtx to smp_ipi_mtx and "SMP IPI lock" or some such. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org