From owner-freebsd-current@FreeBSD.ORG Thu Jun 16 00:41:33 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 4D0F316A41C for ; Thu, 16 Jun 2005 00:41:33 +0000 (GMT) (envelope-from mohan_srinivasan@yahoo.com) Received: from web80606.mail.yahoo.com (web80606.mail.yahoo.com [66.218.79.95]) by mx1.FreeBSD.org (Postfix) with SMTP id 2729443D48 for ; Thu, 16 Jun 2005 00:41:33 +0000 (GMT) (envelope-from mohan_srinivasan@yahoo.com) Received: (qmail 34624 invoked by uid 60001); 16 Jun 2005 00:41:32 -0000 Message-ID: <20050616004132.34622.qmail@web80606.mail.yahoo.com> Received: from [64.168.22.148] by web80606.mail.yahoo.com via HTTP; Wed, 15 Jun 2005 17:41:32 PDT Date: Wed, 15 Jun 2005 17:41:32 -0700 (PDT) From: Mohan Srinivasan To: current@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: Subject: 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 00:41:33 -0000 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