From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754688Ab0DTN2s (ORCPT ); Tue, 20 Apr 2010 09:28:48 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:59286 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754444Ab0DTN2r (ORCPT ); Tue, 20 Apr 2010 09:28:47 -0400 Date: Tue, 20 Apr 2010 06:28:39 -0700 From: "Paul E. McKenney" To: Eric Paris Cc: Lai Jiangshan , Ingo Molnar , Peter Zijlstra , Miles Lane , LKML Subject: Re: [PATCH] RCU: don't turn off lockdep when find suspicious rcu_dereference_check() usage Message-ID: <20100420132839.GB2628@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20100311032843.GE6767@linux.vnet.ibm.com> <1271098032.4807.137.camel@twins> <1271242058.32749.19.camel@laptop> <1271701612.2972.5.camel@dhcp231-113.rdu.redhat.com> <20100419230136.GA16856@linux.vnet.ibm.com> <1271726729.2972.13.camel@dhcp231-113.rdu.redhat.com> <20100420030452.GB2905@linux.vnet.ibm.com> <4BCD646B.1080206@cn.fujitsu.com> <1271766716.2972.16.camel@dhcp231-113.rdu.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1271766716.2972.16.camel@dhcp231-113.rdu.redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 20, 2010 at 08:31:56AM -0400, Eric Paris wrote: > On Tue, 2010-04-20 at 16:23 +0800, Lai Jiangshan wrote: > > > [PATCH] RCU: don't turn off lockdep when find suspicious rcu_dereference_check() usage > > > > When suspicious rcu_dereference_check() usage is detected, lockdep is still > > available actually, so we should not call debug_locks_off() in > > lockdep_rcu_dereference(). > > > > For get rid of too much "suspicious rcu_dereference_check() usage" > > output when the "if(!debug_locks_off())" statement is removed. This patch uses > > static variable '__warned's for very usage of "rcu_dereference*()". > > > > One variable per usage, so, Now, we can get multiple complaint > > when we detect multiple different suspicious rcu_dereference_check() usage. > > > > Requested-by: Eric Paris > > Signed-off-by: Lai Jiangshan > > Although mine was a linux-next kernel and it doesn't appear that I have > rcu_dereference_protected() at all, so I dropped that bit of the patch, > it worked great! I got 4 more complaints to harass people with. Feel > free to add my tested by if you care to. > > Tested-by: Eric Paris Very nice!!! Queued for urgent, thank you Lai and Eric!!! Thanx, Paul