From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933367AbcCIQkX (ORCPT ); Wed, 9 Mar 2016 11:40:23 -0500 Received: from foss.arm.com ([217.140.101.70]:40924 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933176AbcCIQkT (ORCPT ); Wed, 9 Mar 2016 11:40:19 -0500 Subject: Re: [PATCH -next] tracepoint: ipi: don't trace IPI on offline CPUs To: Steven Rostedt References: <1457526142-31923-1-git-send-email-sudeep.holla@arm.com> <20160309110539.603293db@gandalf.local.home> Cc: Sudeep Holla , linux-kernel@vger.kernel.org, Ingo Molnar From: Sudeep Holla Organization: ARM Message-ID: <56E051F0.9030800@arm.com> Date: Wed, 9 Mar 2016 16:40:16 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160309110539.603293db@gandalf.local.home> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/03/16 16:05, Steven Rostedt wrote: > On Wed, 9 Mar 2016 12:22:22 +0000 > Sudeep Holla wrote: > > >> Hi Steven, >> >> I observed that in "include/linux/tracepoint.h", we have >> #define __DO_TRACE(tp, proto, args, cond, prercu, postrcu) >> ... >> if (!cpu_online(raw_smp_processor_id())) >> return; >> >> if (!(cond)) >> return; >> ... >> >> where !cond check seems reduntant if it's cpu_online check. >> So, does this patch handle the warning correctly or is there any better >> way ? I did see few traces with same condition, just thought of checking >> with you. >> > > Bah, I forgot that we have lockdep checks for when the event isn't > enabled. Yes I was about to ask you the same. I did further digging to check if I was missing something after seeing your series[1] especially patch 2/12 (tracing: Remove duplicate checks for online CPUs) > Can you try this patch: It works. Thanks for the quick fix. Tested-by: Sudeep Holla -- Regards, Sudeep [1] http://www.spinics.net/lists/kernel/msg2208604.html