From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751546AbZHXHxt (ORCPT ); Mon, 24 Aug 2009 03:53:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751167AbZHXHxt (ORCPT ); Mon, 24 Aug 2009 03:53:49 -0400 Received: from rv-out-0506.google.com ([209.85.198.237]:59699 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974AbZHXHxs (ORCPT ); Mon, 24 Aug 2009 03:53:48 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Ink+/jO29bjHDuFnExhewOrhgtang5ltWyS6UoJ9wF2FEe4fO5eRJ7OxQRaMsMoG7X +48dFyBf+sMjx2CETKo8qlpEGjpvqZa2fvYIr7tKt1nQW+YqF7EWbScWIyCsX8KXF2sY /UNvTj4/pGSLsJ1BbdU0ignW/QlFZ14vPis7k= Message-ID: <4A924720.3060205@gmail.com> Date: Mon, 24 Aug 2009 00:54:08 -0700 From: "Justin P. Mattock" User-Agent: Spicebird/0.7.1 (X11; 2009022519) MIME-Version: 1.0 To: Peter Zijlstra CC: Li Zefan , Steven Rostedt , Frederic Weisbecker , Linux Kernel Mailing List , Ingo Molnar Subject: Re: system gets stuck in a lock during boot References: <4A84345D.60506@gmail.com> <20090818104905.GC5231@nowhere> <20090818160911.GA21243@goodmis.org> <4A8B4607.6090303@gmail.com> <4A8B5113.20102@cn.fujitsu.com> <4A8FA2BD.4030707@gmail.com> <4A91FDED.9050801@cn.fujitsu.com> <1251093523.7538.118.camel@twins> <4A922F82.9080000@cn.fujitsu.com> <1251096925.7538.121.camel@twins> In-Reply-To: <1251096925.7538.121.camel@twins> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra wrote: > On Mon, 2009-08-24 at 14:13 +0800, Li Zefan wrote: > >> Peter Zijlstra wrote: >> >>> On Mon, 2009-08-24 at 10:41 +0800, Li Zefan wrote: >>> >>> >>>>> @@ -940,7 +940,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentr >>>>> entry = trace_create_file("enable", 0644, call->dir, call, >>>>> enable); >>>>> >>>>> - if (call->id) >>>>> + if (call->id&& call->profile_enable) >>>>> >>>> We do an extra check on ->profile_enable, shouldn't cause bug.. >>>> >>>> >>>>> entry = trace_create_file("id", 0444, call->dir, call, >>>>> id); >>>>> >>>> Any way, I don't think this commit does the right thing: >>>> >>>> - If CONFIG_EVENT_PROFILE=y, we'll create events///id, >>>> except events/ftrace//id. >>>> >>>> - if CONFIG_EVENT_PROFILE=n, there's no 'id' file at all! >>>> >>>> I think it's better to skip ftrace/ dir in perf tool code, instead of >>>> skipping creating id files in ftrace code. >>>> >>> No, it does do the right thing. Your patch breaks things because not all >>> tracepoints are created through TRACE_EVENT() and will thus not have >>> their profile_enable/disable hooks set. >>> >>> By giving them an ID file, there is no way to distinguish good from bad >>> tracepoints. >>> >>> >> But removing the id file from events/ftrace/ might break some ftrace >> binary parsers? >> >> And this commit makes 'id' file disapeared with CONFIG_EVENT_PROFILE=n. >> > > I introduced the id file for EVENT_PROFILE, tough luck if someone else > relies on it. > > >>> Expempting ftrace is no solid solution, suppose someone else does a >>> TRACE_EVENT_FORMAT() tracepoint, how would you know you could use it as >>> a profile event source? >>> >>> >> Agree. >> >> >>> The id files really must stay conditional. >>> >>> >> I don't think it's a good idea to connect it with perfcounter >> this way. Wouldn't adding a 'profilable' file more intuitive? >> > > its called: id ;-) > > Alright, I'm going to go back to the beginning and start my build from scratch(make sure things are legit). Justin P. Mattock