From owner-cvs-src@FreeBSD.ORG Wed Aug 4 21:32:38 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from green.homeunix.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id C495216A4CE; Wed, 4 Aug 2004 21:32:37 +0000 (GMT) Received: from green.homeunix.org (green@localhost [127.0.0.1]) by green.homeunix.org (8.12.11/8.12.11) with ESMTP id i74LWb8p059704; Wed, 4 Aug 2004 17:32:37 -0400 (EDT) (envelope-from green@green.homeunix.org) Received: (from green@localhost) by green.homeunix.org (8.12.11/8.12.11/Submit) id i74LWa66059703; Wed, 4 Aug 2004 17:32:36 -0400 (EDT) (envelope-from green) Date: Wed, 4 Aug 2004 17:32:36 -0400 From: Brian Fundakowski Feldman To: John Baldwin Message-ID: <20040804213236.GA58239@green.homeunix.org> References: <200408042031.i74KVKUf039025@repoman.freebsd.org> <200408041634.03998.jhb@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200408041634.03998.jhb@FreeBSD.org> User-Agent: Mutt/1.5.6i cc: cvs-src@FreeBSD.org cc: src-committers@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-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: Wed, 04 Aug 2004 21:32:38 -0000 On Wed, Aug 04, 2004 at 04:34:03PM -0400, John Baldwin wrote: > 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. "No feedback is good feedback" -- those changes have caused no problems for me during non-PREEMPTION-only testing on my dual Athlon. -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\