Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754494Ab0DTMcY (ORCPT ); Tue, 20 Apr 2010 08:32:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14386 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753918Ab0DTMcX (ORCPT ); Tue, 20 Apr 2010 08:32:23 -0400 Subject: Re: [PATCH] RCU: don't turn off lockdep when find suspicious rcu_dereference_check() usage From: Eric Paris To: Lai Jiangshan Cc: paulmck@linux.vnet.ibm.com, Ingo Molnar , Peter Zijlstra , Miles Lane , LKML In-Reply-To: <4BCD646B.1080206@cn.fujitsu.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> Content-Type: text/plain; charset="UTF-8" Date: Tue, 20 Apr 2010 08:31:56 -0400 Message-ID: <1271766716.2972.16.camel@dhcp231-113.rdu.redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1340 Lines: 30 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/