From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933177Ab1KGRzx (ORCPT ); Mon, 7 Nov 2011 12:55:53 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:45625 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932732Ab1KGRzw (ORCPT ); Mon, 7 Nov 2011 12:55:52 -0500 Date: Mon, 7 Nov 2011 09:55:23 -0800 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Stephane Eranian , Li Zefan , Ingo Molnar , eric.dumazet@gmail.com, shaohua.li@intel.com, ak@linux.intel.com, mhocko@suse.cz, alex.shi@intel.com, efault@gmx.de, linux-kernel@vger.kernel.org, Paul Turner Subject: Re: [GIT PULL rcu/next] RCU commits for 3.1 Message-ID: <20111107175523.GK2332@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <4EAA14A1.5060204@cn.fujitsu.com> <20111029182710.GG6160@linux.vnet.ibm.com> <4EAE57AF.1060706@cn.fujitsu.com> <20111031093256.GI6160@linux.vnet.ibm.com> <4EAF5B68.8090005@cn.fujitsu.com> <1320678902.18053.63.camel@twins> <1320683756.17809.28.camel@twins> <20111107165603.GD2332@linux.vnet.ibm.com> <1320685789.17809.30.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1320685789.17809.30.camel@twins> User-Agent: Mutt/1.5.20 (2009-06-14) x-cbid: 11110717-8974-0000-0000-0000018B39CC Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2011 at 06:09:49PM +0100, Peter Zijlstra wrote: > On Mon, 2011-11-07 at 08:56 -0800, Paul E. McKenney wrote: > > > > If this really is a false positive, what should be used to get rid of > > the splats? > > > Probably something slightly less horrid than the below.. ;-) Hmmm... Could the "1" below be replaced by the task's reference count? Probabilistic, but should eventually catch it. Thanx, Paul > --- > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index d1a1bee..8f05201 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -229,7 +229,7 @@ static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, > static inline struct perf_cgroup * > perf_cgroup_from_task(struct task_struct *task) > { > - return container_of(task_subsys_state(task, perf_subsys_id), > + return container_of(task_subsys_state_check(task, perf_subsys_id, 1), > struct perf_cgroup, css); > } > >