From owner-freebsd-current@FreeBSD.ORG Thu Jun 16 01:50:51 2005 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 44CED16A41C for ; Thu, 16 Jun 2005 01:50:51 +0000 (GMT) (envelope-from ups@tree.com) Received: from smtp.speedfactory.net (smtp.speedfactory.net [66.23.216.216]) by mx1.FreeBSD.org (Postfix) with ESMTP id F284543D48 for ; Thu, 16 Jun 2005 01:50:50 +0000 (GMT) (envelope-from ups@tree.com) Received: (qmail 6792 invoked from network); 16 Jun 2005 01:50:58 +0000 Received: from 66-23-216-49.clients.speedfactory.net (HELO palm.tree.com) (66.23.216.49) by smtp.speedfactory.net with AES256-SHA encrypted SMTP; 16 Jun 2005 01:50:58 +0000 Received: from [127.0.0.1] (ups@localhost.tree.com [127.0.0.1]) by palm.tree.com (8.12.10/8.12.10) with ESMTP id j5G1okpP032230; Wed, 15 Jun 2005 21:50:47 -0400 (EDT) (envelope-from ups@tree.com) From: Stephan Uphoff To: Mohan Srinivasan In-Reply-To: <20050616004132.34622.qmail@web80606.mail.yahoo.com> References: <20050616004132.34622.qmail@web80606.mail.yahoo.com> Content-Type: text/plain Message-Id: <1118886645.27369.128919.camel@palm> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 15 Jun 2005 21:50:46 -0400 Content-Transfer-Encoding: 7bit Cc: "current@freebsd.org" Subject: Re: Kernel lockmgr races LK_UPGRADE against LK_SHARED... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Jun 2005 01:50:51 -0000 On Wed, 2005-06-15 at 20:41, Mohan Srinivasan wrote: > This is on 4.x, but I'm posting to current, it's likely also > an issue on current. Posting here hoping someone can shed > more info on this lockmgr race. > > I've into a bug where process 1 successfully LK_UPGRADEs a > vnode lock (from shared to excl) and process 2 successfully > acquires the shared lock on that same vnode. I am not sure > what order the locks were acquired, it's not possible to > infer that from the core. > > Does this bug ring a bell with anyone ? If it does, can they > shed any light/info they might have on this ? > > thanks > > mohan Reminds me of: http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/69934 Stephan