From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750725AbWFEINA (ORCPT ); Mon, 5 Jun 2006 04:13:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750726AbWFEINA (ORCPT ); Mon, 5 Jun 2006 04:13:00 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:51635 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1750725AbWFEINA (ORCPT ); Mon, 5 Jun 2006 04:13:00 -0400 Date: Mon, 5 Jun 2006 10:12:20 +0200 From: Ingo Molnar To: "Barry K. Nathan" Cc: Valdis.Kletnieks@vt.edu, Andrew Morton , arjan@linux.intel.com, linux-kernel@vger.kernel.org, reiserfs-dev@namesys.com, Hans Reiser Subject: Re: 2.6.17-rc5-mm3: bad unlock ordering (reiser4?) Message-ID: <20060605081220.GA30123@elte.hu> References: <986ed62e0606040504n148bf744x77bd0669a5642dd0@mail.gmail.com> <20060604133326.f1b01cfc.akpm@osdl.org> <200606042056.k54KuoKQ005588@turing-police.cc.vt.edu> <20060604213432.GB5898@elte.hu> <986ed62e0606041503v701f8882la4cbead47ae3982f@mail.gmail.com> <20060605065444.GA27445@elte.hu> <986ed62e0606050058v21b457a7tb4da4da62cb7e4e3@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <986ed62e0606050058v21b457a7tb4da4da62cb7e4e3@mail.gmail.com> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5971] 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Barry K. Nathan wrote: > On 6/4/06, Ingo Molnar wrote: > >reporting the first one only is necessary, because the validator cannot > >trust a system's dependency info that it sees as incorrect. Deadlock > >possibilities are quite rare in a kernel that is "in balance". Right now > >we are not "in balance" yet, because the validator has only been added a > >couple of days ago. The flurry of initial fixes will die down quickly. > > So, does that mean the plan is to annotate/tweak things in order to > shut up *each and every* false positive in the kernel? yes. Note that for the many reasons i outlined before they are only "half false positives" - i.e. they are potentially dangerous constructs and they are potentially inefficient - hence we _want to_ document them in the code, to increase the cleanliness of the kernel. A pure "false positive" would be a totally valid and perfect locking construct being flagged by the lock validator. nor do these warnings really hurt anyone. Lockdep prints info and then shuts up - the system continues to work. > Anyway, I tried your patch and I got this: please try the addon patch below. Ingo Index: linux/fs/reiser4/txnmgr.h =================================================================== --- linux.orig/fs/reiser4/txnmgr.h +++ linux/fs/reiser4/txnmgr.h @@ -567,7 +567,7 @@ static inline void spin_unlock_txnh(txn_ LOCK_CNT_DEC(spin_locked_txnh); LOCK_CNT_DEC(spin_locked); - spin_unlock(&(txnh->hlock)); + spin_unlock_non_nested(&(txnh->hlock)); } #define spin_ordering_pred_txnmgr(tmgr) \