From owner-svn-src-head@FreeBSD.ORG Thu Mar 22 19:13:40 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 22E031065674; Thu, 22 Mar 2012 19:13:40 +0000 (UTC) (envelope-from jkim@FreeBSD.org) From: Jung-uk Kim To: John Baldwin Date: Thu, 22 Mar 2012 15:13:28 -0400 User-Agent: KMail/1.6.2 References: <201203202037.q2KKbNfK037014@svn.freebsd.org> <4F6AF1CB.80902@FreeBSD.org> <201203220748.49635.jhb@freebsd.org> In-Reply-To: <201203220748.49635.jhb@freebsd.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201203221513.32171.jkim@FreeBSD.org> Cc: Konstantin Belousov , "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" , Andriy Gapon 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: Thu, 22 Mar 2012 19:13:40 -0000 On Thursday 22 March 2012 07:48 am, John Baldwin wrote: > On Thursday, March 22, 2012 5:32:59 am Andriy Gapon wrote: > > on 21/03/2012 21:02 Jung-uk Kim said the following: > > > On Wednesday 21 March 2012 01:57 pm, Andriy Gapon wrote: > > >> on 21/03/2012 19:41 Jung-uk Kim said the following: > > >>> 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. > > >> > > >> But the bug still has to be fixed, right? > > >> Even if it takes a non-default sysctl value to give the bug a > > >> chance. > > > > > > Ideally, yes. However, I am not so sure if we can call it a > > > "bug" because AcpiEnterSleepState() must be called with > > > interrupt disabled and there is no way to change that API > > > without breaking other OSes. We can only work around it locally > > > or persuade upstream to find a better way to do this in ACPICA > > > itself. Either way, it will be pretty hackish. :-( > > > > I see. Thank you. > > Maybe the code could be somehow tricked into using M_NOWAIT in > > this > > context... > > That still wouldn't be good enough. We don't want to try to > acquire any regular mutexes either (we can't safely block to let > the lock owner run, or the lock owner might be a suspended thread > on another CPU, etc.). The only proper way to fix this would be to > use pre-allocated storage in this particular case, but given that > Windows doesn't invoke these methods on suspend/resume, it's > doubtful that we will ever need to do so. FYI, I filed an upstream PR to track this issue: http://acpica.org/bugzilla/show_bug.cgi?id=950 Jung-uk Kim