From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752701AbeAXANC (ORCPT ); Tue, 23 Jan 2018 19:13:02 -0500 Received: from mga05.intel.com ([192.55.52.43]:9310 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752455AbeAXANB (ORCPT ); Tue, 23 Jan 2018 19:13:01 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,404,1511856000"; d="scan'208";a="13686668" Subject: Re: [PATCH] perf util: Use target->per_thread and target->system_wide flags To: Jiri Olsa Cc: Mathieu Poirier , Arnaldo Carvalho de Melo , jolsa@kernel.org, Peter Zijlstra , Ingo Molnar , Alexander Shishkin , Linux-kernel@vger.kernel.org, Andi Kleen , kan.liang@intel.com, yao.jin@intel.com References: <1516659340-30289-1-git-send-email-yao.jin@linux.intel.com> <06929c28-6431-29f2-340e-6dbc2302c78b@linux.intel.com> <20180123144033.GA24739@krava> From: "Jin, Yao" Message-ID: Date: Wed, 24 Jan 2018 08:12:33 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <20180123144033.GA24739@krava> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/23/2018 10:40 PM, Jiri Olsa wrote: > On Tue, Jan 23, 2018 at 07:02:44AM +0800, Jin, Yao wrote: > > SNIP > >>>> threads = thread_map__new_str(target->pid, target->tid, target->uid, >>>> - target->per_thread); >>>> + target->per_thread && target->system_wide); >>> >>> At first glance I thought your solution would do the trick but perf >>> record does use target->system_wide when the '-a' switch is used. >>> Moreover specifying the '-a' switch doesn't prevent the '--per-thread' >>> option from being used as well, making both target->perf_thread and >>> target_system_wide equal to true (and that is not good). >>> >>> Although not a fan of adding more to struct target, the advantage of >>> having target->all_threads is that we are guaranteed that it isn't >>> used anywhere else. >>> >>> Let me know what you think, >>> Mathieu >>> >> >> If we specify both '-a' and '--per-thread' to perf record, perf record will >> override'--per-thread'. So now target->per_thread = false, and >> target->system_wide = true. >> >> If we specify '--per-thread' only to perf record, target->per_thread = true, >> and target->system_wide = false. >> >> So whatever for any case, target->per_thread && target->system_wide is >> false. >> >> Since the parameter is false, in thread_map__new_str(), it will not execute >> the thread_map__new_all_cpus(). So that will not change perf record previous >> behavior. >> >> In perf stat, it allows the case that target->per_thread and >> target->system_wide are all true. That means we want to collect system-wide >> per-thread metrics. > > could you please put this description into comment > before the thread_map__new_str is called? > > thanks, > jirka > OK, I will put this comment in v2. I will send v2 soon. Thanks Jin Yao