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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 9F09DC433DF for ; Sat, 8 Aug 2020 02:22:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 762D92087C for ; Sat, 8 Aug 2020 02:22:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IsbJCfT9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726382AbgHHCWT (ORCPT ); Fri, 7 Aug 2020 22:22:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726186AbgHHCWS (ORCPT ); Fri, 7 Aug 2020 22:22:18 -0400 Received: from mail-qt1-x841.google.com (mail-qt1-x841.google.com [IPv6:2607:f8b0:4864:20::841]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36B76C061756 for ; Fri, 7 Aug 2020 19:22:18 -0700 (PDT) Received: by mail-qt1-x841.google.com with SMTP id b25so2782767qto.2 for ; Fri, 07 Aug 2020 19:22:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ecrnqYOvc4eCeauMfs2J6ltj0dBor5l9FCOKfk/i2NE=; b=IsbJCfT9oVZ5agxDiVijRJYQ9e6JAKIQZC1Wx5njAoRkdcMK1YNS/yaBEJVw9hyJ+1 O41sdyPfGqA1ihXW3L4Z92E57qUtjHb0azYl+jTGL/0b+r80ycB32zdcHepRTJZ6Zv+c NJNYv6+FTcpAMqRrh2XRp3nGn9i9Z2B76FI9zCscozBtGfOcGEVyx3WsoL6/krziaQju sYfDUEI1a7DWTDkAPQRASLvRVwHo0tSWFdl/SiNBpS/UpddzIJhghPGTARUxVz3X/KjY MtqtGg3CXuuB1IGA6i/A3mgJigRTBO7hl3cKduviJ4YCJ0q7ZcA7k+2DFzyLL2+kU17U V3sQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ecrnqYOvc4eCeauMfs2J6ltj0dBor5l9FCOKfk/i2NE=; b=qxYqYtXfLnkSu6msvCkKj0xp9os9y28l+W2MglsB2tsdVnbafiwG/o4ugYcdtOHFEB xucuasdegbRXdeGljt+fPcZb1xqi9uis+8etPL6W9ELJ0xG74QAEfxpPaX35Fs49kq8h 9TXXVfi8WWVVUP794zPg3yLjLop77RqCmpYTqnhyU2caHZ8ei78Ej4I83TlkMnfb8rHO 1Yj9Fq52pEUCPoISz7rCiT7zx4GsBJPXpSpaif8rK8bgzA4xY0v1AqbM52rML/zy6gET GFk9thzxwqwWWFKBl8LRcxl5eyYVa8wI3sOJZcVbjX+oQkxX6+HWwpGHLnYiQqyYVF3a CHVg== X-Gm-Message-State: AOAM533qPPQTrkmDz1TBvYLs7Igc0F06hPgxYsoPqRtfZe2rZBcFF0l9 xU8mgWWAYGK+58JBM8KWmr4= X-Google-Smtp-Source: ABdhPJxM5y4L5rKuVDondHa1v4nK0PZ4ONWX1OVrNFgG4YC4bDVvflESho0SwrLV22yC7pbRhQlDnw== X-Received: by 2002:ac8:4c8e:: with SMTP id j14mr17652215qtv.381.1596853337361; Fri, 07 Aug 2020 19:22:17 -0700 (PDT) Received: from mail.google.com ([66.42.85.36]) by smtp.gmail.com with ESMTPSA id e4sm9412771qts.57.2020.08.07.19.22.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Aug 2020 19:22:16 -0700 (PDT) Date: Sat, 8 Aug 2020 10:22:03 +0800 From: Changbin Du To: Arnaldo Carvalho de Melo Cc: Changbin Du , Jiri Olsa , Peter Zijlstra , Ingo Molnar , Namhyung Kim , Steven Rostedt , linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 01/18] perf ftrace: select function/function_graph tracer automatically Message-ID: <20200808022203.yqadm2verquocjrg@mail.google.com> References: <20200718064826.9865-1-changbin.du@gmail.com> <20200718064826.9865-2-changbin.du@gmail.com> <20200804125115.GF3440834@kernel.org> <20200806001448.ln2u7qyc4fnuk5lh@mail.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 05, 2020 at 10:05:03PM -0300, Arnaldo Carvalho de Melo wrote: > > > On August 5, 2020 9:14:48 PM GMT-03:00, Changbin Du wrote: > >On Tue, Aug 04, 2020 at 09:51:15AM -0300, Arnaldo Carvalho de Melo > >wrote: > >> Em Sat, Jul 18, 2020 at 02:48:09PM +0800, Changbin Du escreveu: > >> > 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. > >> > - If '-g' or '-G' option is on, then function_graph tracer is > >used. > >> > - The perf configuration item 'ftrace.tracer' is marked as > >deprecated. > >> > - The option '--tracer' is marked as deprecated. > >> > >> You should try to be more granular, for instance, I think the > >decision > >> to change the default is questionable, but could be acceptable. > >> > >> But why deprecate the perf configuration for the default tracer? > >> > >> Say people who already use 'perf ftrace ls' go and use with this > >patch > >> and see that it changed the default from the function_graph tracer to > >> the function tracer and disagree with you, they want the default to > >be > >> the function graph tracer, know that there is (or there was) a > >> ftrace.tracer in ~/.prefconfig, and then try that, only to find out > >that > >> it is not possible, frustrating :-\ > >> > >> So can we please remove this deprecation of ftrace.tracer so that > >people > >> used to how it was can get that behaviour back? > >> > >Agreed. If no -F or -G is given, we can use the ftrace.tracer as > >default tracer. > >Let me update it. Thanks. > > Thanks, I'm general try to be as granular as possible, doing one thing per patch, this way the reviewer can do some preliminary cherry picking and we also improve git bisectability. > Arnaldo, I changed the policy as below: - Preserve the default tracerr which is function_graph. - If '-g' or '-G' option is on, then function_graph tracer is used. - If '-T' or '-N' option is on, then function tracer is used. - The option '--tracer' or configuration ftrace.tracer only takes effect if neither -g/-G nor -T/-N is specified. - The function_graph has priority over function tracer if both -G/-g and -T/-N are given. Please check updatae in v8. Thanks. > - Arnaldo > > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. -- Cheers, Changbin Du