From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752173AbcLFD5u (ORCPT ); Mon, 5 Dec 2016 22:57:50 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34944 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500AbcLFD5r (ORCPT ); Mon, 5 Dec 2016 22:57:47 -0500 Subject: Re: [PATCH 04/10] perf sched timehist: Split is_idle_sample() To: Namhyung Kim , Arnaldo Carvalho de Melo References: <20161206034010.6499-1-namhyung@kernel.org> <20161206034010.6499-5-namhyung@kernel.org> Cc: Ingo Molnar , Peter Zijlstra , Jiri Olsa , LKML , Andi Kleen , Minchan Kim From: David Ahern Message-ID: <06f40aab-8f66-e727-3a37-3f2657f6bba6@gmail.com> Date: Mon, 5 Dec 2016 19:57:43 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161206034010.6499-5-namhyung@kernel.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/5/16 7:40 PM, Namhyung Kim wrote: > The is_idle_sample() function actually does more than determining > whether sample come from idle task. Split the callchain part into > save_task_callchain() to make it clearer. Also checking prev_pid from > trace data looks unnecessary since it should be always same as > sample->pid. The timehist command is 3-4 years old now, and over that time it has been used on a variety of OS'es -- RHEL6, WRL5, WRL6, various Fedora and debian releases, etc. The idle_sample checks were added for a reason. Given the range of kernels that have sched tracepoints I'd be wary of just removing it regardless of how silly it seems against top of tree kernels.