From owner-p4-projects@FreeBSD.ORG Thu Nov 2 22:07:32 2006 Return-Path: X-Original-To: p4-projects@freebsd.org Delivered-To: p4-projects@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 32767) id 30D9216A514; Thu, 2 Nov 2006 22:07:32 +0000 (UTC) X-Original-To: perforce@freebsd.org Delivered-To: perforce@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 085D316A4DA; Thu, 2 Nov 2006 22:07:32 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (66-23-211-162.clients.speedfactory.net [66.23.211.162]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6F64C43D67; Thu, 2 Nov 2006 22:07:29 +0000 (GMT) (envelope-from jhb@freebsd.org) Received: from zion.baldwin.cx (zion.baldwin.cx [192.168.0.7]) (authenticated bits=0) by server.baldwin.cx (8.13.6/8.13.6) with ESMTP id kA2M7FQw015381; Thu, 2 Nov 2006 17:07:22 -0500 (EST) (envelope-from jhb@freebsd.org) From: John Baldwin To: Scott Long Date: Thu, 2 Nov 2006 12:31:52 -0500 User-Agent: KMail/1.9.1 References: <200611010112.kA11C1Jt066210@repoman.freebsd.org> <200611021151.19396.jhb@freebsd.org> <454A2679.4030609@samsco.org> In-Reply-To: <454A2679.4030609@samsco.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200611021231.53607.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [192.168.0.1]); Thu, 02 Nov 2006 17:07:22 -0500 (EST) X-Virus-Scanned: ClamAV 0.88.3/2151/Thu Nov 2 13:35:18 2006 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.1 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00, DATE_IN_PAST_03_06 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: Perforce Change Reviews , Scott Long , Hans Petter Selasky Subject: Re: PERFORCE change 108878 for review X-BeenThere: p4-projects@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: p4 projects tree changes List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Nov 2006 22:07:32 -0000 On Thursday 02 November 2006 12:10, Scott Long wrote: > John Baldwin wrote: > > On Thursday 02 November 2006 06:22, Hans Petter Selasky wrote: > > > >>On Wednesday 01 November 2006 16:47, John Baldwin wrote: > >> > >>>On Tuesday 31 October 2006 20:12, Scott Long wrote: > >>> > >>>>http://perforce.freebsd.org/chv.cgi?CH=108878 > >>>> > >>>>Change 108878 by scottl@scottl-x64 on 2006/11/01 01:11:30 > >>>> > >>>> For some wonderful reason, you cannot pass &Giant to msleep. Work > >>>> around that in a crude fashion. Also add some more assertions. > >>> > >>>Ah, yes, that would be most unhappy. I guess mostly the idea is that Giant > >>>should be rather implicit and explicitly using Giant for an object lock is > >>>discouraged. I'm not sure that is what you are doing though. I think > >>>maybe you are borrowing Giant that's already held? > >> > >>I use this patch: > >> > >>/* preliminary fix for a bug in msleep on FreeBSD, > >> * which cannot sleep with Giant: > >> */ > >>#define msleep(i,m,p,w,t) msleep(i,(((m) == &Giant) ? NULL : (m)),p,w,t) > >> > >>Really this issue should be fixed. It happens just because GIANT_DROP is done > >>too early in "msleep()". > > > > > > Giant is special in msleep() and friends to make sure it is first in the > > lock order, but unlock doesn't matter for lock order, and actually, the > > current order is less intuitive. I think it's the way it is now because we > > inherited it from BSD/OS. Also in theory old code under Giant should be > > using tsleep() and not msleep() anyway. It actually won't hurt to move > > DROP_GIANT later though. > > > > How about this: > > > > This won't work for what I'm using it for. It's not a big deal, though. ? It should make msleep(&Giant) work just the same as msleep(&foo). In this case if Giant is only singly locked, DROP_GIANT just won't do anything. -- John Baldwin