From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE693C433E0 for ; Sun, 31 May 2020 05:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C28F120723 for ; Sun, 31 May 2020 05:52:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590904358; bh=+QcMi2v0X2QopR6KHQ4I5yo93LQLeA2NFJr6164Zi4w=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=D881JbwDdEHfG4W8MisgrrVFx9j9xB9QB8KTZfyR4C7PZylveqMHWdeJRg62/kJrq 48QAJ8nJo+svS0uAp8RM02nXbFBYOZmhR/tzETRvbp0XkEuX+AsHw4K6hcASnUPthv TF6zH8eiWLR4rqNfXfYmyIpPdAGg5OMUxe0TcImU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728049AbgEaFwh (ORCPT ); Sun, 31 May 2020 01:52:37 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:45862 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725898AbgEaFwh (ORCPT ); Sun, 31 May 2020 01:52:37 -0400 Received: by mail-ed1-f68.google.com with SMTP id s19so4786286edt.12 for ; Sat, 30 May 2020 22:52:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lEESxdWkBaFZaHt1Qo9sGBPt3NVRbxITfikSAaK4xFw=; b=Gs028hPWlUOhIRwh6kYt9kMoZPHPsTMnaVkFikkwNVEI5HBlrf4a/CKZOz9xXlsyTj CpgaZcNKAIA+FfZGjEUHWzkRU2OYHvJ9u15lejmazyy++HIcY16f7KQ9WrtvS5B+kh0r CLWU65jGnWdI/nXPvtHPBQSHb5gKDulZ7s8awCE9RFSz1OXDZ95lnJp4nE7XzsIH8ZfD 6PVDjE4vpkzs1qnbvI/4rcC1b4r7me1lkrIWc8h+OfsWQREBB3ggilFcxrGVwFoi5dUn qIoP4EN6UjeC3796WnItEzQ2tuW1hMnHM7fJY99lckBZxT+c1eQtPt2WownpahyY3k/m p/ew== X-Gm-Message-State: AOAM531IfM81gSpKqsIEYyW4YqkX4cfvayvlTSttUGv9J/30soNcZO7I 7sJDRJi3PyarVgJDhwtlEZ03tiVwvVPytEsiP4o9Uw== X-Google-Smtp-Source: ABdhPJwU1L3H4lm0iPH1LESIa0ELFZFrlSzAWxKU7ukQ81bUZMiS+gPAVaoKl8+cqXRy9Uc3ji9h8WcCtYfBVWWSnlg= X-Received: by 2002:adf:a50e:: with SMTP id i14mr4342367wrb.21.1590904354886; Sat, 30 May 2020 22:52:34 -0700 (PDT) MIME-Version: 1.0 References: <20200510150628.16610-1-changbin.du@gmail.com> <20200510150628.16610-4-changbin.du@gmail.com> In-Reply-To: <20200510150628.16610-4-changbin.du@gmail.com> From: Namhyung Kim Date: Sun, 31 May 2020 14:52:23 +0900 Message-ID: Subject: Re: [PATCH 03/19] perf ftrace: select function/function_graph tracer automatically To: Changbin Du Cc: Jiri Olsa , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Steven Rostedt , linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Mon, May 11, 2020 at 12:07 AM Changbin Du wrote: > > The '-g/-G' options have already implied function_graph tracer should be > used instead of function tracer. So the extra option '--tracer' can be > killed. > > This patch changes the behavior as below: > - By default, function tracer is used. Why? You also removed -t/--tracer option. > - If '-g' or '-G' option is on, then function_graph tracer is used. I'm ok with this. > - The perf configuration item 'ftrace.tracer' is removed. Why? > - The default filter for -G is to trace all functions. There's no reason to use -G option then. Also It might be confusing if it sees an argument - whether it's a function or a workload. I just don't know why you want to change this as we have a way to change the default tracer already. Thanks Namhyung