From owner-svn-src-head@FreeBSD.ORG Wed Mar 21 17:41:20 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from [127.0.0.1] (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by hub.freebsd.org (Postfix) with ESMTP id 528DB1065674; Wed, 21 Mar 2012 17:41:20 +0000 (UTC) (envelope-from jkim@FreeBSD.org) From: Jung-uk Kim To: Konstantin Belousov Date: Wed, 21 Mar 2012 13:41:03 -0400 User-Agent: KMail/1.6.2 References: <201203202037.q2KKbNfK037014@svn.freebsd.org> <20120321100722.GP2358@deviant.kiev.zoral.com.ua> In-Reply-To: <20120321100722.GP2358@deviant.kiev.zoral.com.ua> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201203211341.11859.jkim@FreeBSD.org> Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" Subject: Re: svn commit: r233249 - head/sys/amd64/acpica X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Mar 2012 17:41:21 -0000 On Wednesday 21 March 2012 06:07 am, Konstantin Belousov wrote: > On Tue, Mar 20, 2012 at 08:37:23PM +0000, Jung-uk Kim wrote: > > Author: jkim > > Date: Tue Mar 20 20:37:23 2012 > > New Revision: 233249 > > URL: http://svn.freebsd.org/changeset/base/233249 > > > > Log: > > Fix another witness panic. We cannot enter critical section at > > all because AcpiEnterSleepState() executes (optional) _GTS method > > since ACPICA 20120215 (r231844). To evaluate the method, we need > > malloc(9), which may sleep. > > You papered over the issue, and not fixed it. Yes, it is a stopgap. > If sleep may happen, as it is for malloc, you cannot sleep with > interrupts turned off. This would cause a deadlock at best. I am well aware of the problem. In fact, that's why I had to merge ACPICA 20120320 rather quickly, which added a new flag to not execute _GTS method. Both _GTS and _BFS are turned off by default. You can control them with a new tunable "debug.acpi.sleep_flags" if you want. Please see the updated acpi(4). Jung-uk Kim