From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752232AbaCFReL (ORCPT ); Thu, 6 Mar 2014 12:34:11 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.231]:3998 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751190AbaCFReJ (ORCPT ); Thu, 6 Mar 2014 12:34:09 -0500 Date: Thu, 6 Mar 2014 12:34:03 -0500 From: Steven Rostedt To: Ingo Molnar Cc: Romain Izard , Frederic Weisbecker , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] trace: module: Maintain a valid user count Message-ID: <20140306123403.5f29c071@gandalf.local.home> In-Reply-To: <1393924179-9147-1-git-send-email-romain.izard.pro@gmail.com> References: <20140303133330.7031b2cb@gandalf.local.home> <1393924179-9147-1-git-send-email-romain.izard.pro@gmail.com> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.130:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo, You want to push this to Linus? Reviewed-by: Steven Rostedt -- Steve On Tue, 4 Mar 2014 10:09:39 +0100 Romain Izard wrote: > The replacement of the 'count' variable by two variables 'incs' and > 'decs' to resolve some race conditions during module unloading was done > in parallel with some cleanup in the trace subsystem, and was integrated > as a merge. > > Unfortunately, the formula for this replacement was wrong in the tracing > code, and the refcount in the traces was not usable as a result. > > Use 'count = incs - decs' to compute the user count. > > Signed-off-by: Romain Izard > --- > include/trace/events/module.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/trace/events/module.h b/include/trace/events/module.h > index 161932737416..ca298c7157ae 100644 > --- a/include/trace/events/module.h > +++ b/include/trace/events/module.h > @@ -78,7 +78,7 @@ DECLARE_EVENT_CLASS(module_refcnt, > > TP_fast_assign( > __entry->ip = ip; > - __entry->refcnt = __this_cpu_read(mod->refptr->incs) + __this_cpu_read(mod->refptr->decs); > + __entry->refcnt = __this_cpu_read(mod->refptr->incs) - __this_cpu_read(mod->refptr->decs); > __assign_str(name, mod->name); > ), >