From owner-cvs-all@FreeBSD.ORG Wed Aug 4 21:12:44 2004 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EAC0B16A4CE for ; Wed, 4 Aug 2004 21:12:44 +0000 (GMT) Received: from mail5.speakeasy.net (mail5.speakeasy.net [216.254.0.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id BB11943D31 for ; Wed, 4 Aug 2004 21:12:44 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 30621 invoked from network); 4 Aug 2004 21:12:44 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 4 Aug 2004 21:12:44 -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 i74LCeQG036297; Wed, 4 Aug 2004 17:12:40 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: src-committers@FreeBSD.org Date: Wed, 4 Aug 2004 16:34:03 -0400 User-Agent: KMail/1.6 References: <200408042031.i74KVKUf039025@repoman.freebsd.org> In-Reply-To: <200408042031.i74KVKUf039025@repoman.freebsd.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200408041634.03998.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx cc: cvs-src@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/i386 pmap.c src/sys/kern subr_witness.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Aug 2004 21:12:45 -0000 On Wednesday 04 August 2004 04:31 pm, John Baldwin wrote: > jhb 2004-08-04 20:31:19 UTC > > FreeBSD src repository > > Modified files: > sys/i386/i386 pmap.c > sys/kern subr_witness.c > Log: > Remove a potential deadlock on i386 SMP by changing the lazypmap ipi and > spin-wait code to use the same spin mutex (smp_tlb_mtx) as the TLB ipi > and spin-wait code snippets so that you can't get into the situation of > one CPU doing a TLB shootdown to another CPU that is doing a lazy pmap > shootdown each of which are waiting on each other. With this change, > only one of the CPUs would do an IPI and spin-wait at a time. Both this patch and the previous I have tested locally and also sent out to current@ for testing. However, I received zero feedback (not even useless feedback), so they may theoretically be risky. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org