From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753642AbZKIEbO (ORCPT ); Sun, 8 Nov 2009 23:31:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753448AbZKIEbN (ORCPT ); Sun, 8 Nov 2009 23:31:13 -0500 Received: from mail-pw0-f42.google.com ([209.85.160.42]:51890 "EHLO mail-pw0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753248AbZKIEbM (ORCPT ); Sun, 8 Nov 2009 23:31:12 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:reply-to:to:cc:in-reply-to:references:content-type :organization:date:message-id:mime-version:x-mailer :content-transfer-encoding; b=KZOCoXJKzjS/BkWIQx2FkoRPdr1l9RGVWlpKKd55YEbQtMMRs7xaqG49nig0shxONy podjKHX7xvqG+ZaXMcu6JSRGN3k+9WPVvcniQKw/eobpvqqn4VfrjzxaWVIw6hBVN4dq Dv1oYPtrfwSxB2xyPci/V1+xLK1/1B+3v9CB4= Subject: Re: [PATCH -v5 08/11] tracing: not trace mips_timecounter_init() in MIPS From: Wu Zhangjin Reply-To: wuzhangjin@gmail.com To: Frederic Weisbecker Cc: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, Thomas Gleixner , Ralf Baechle , Nicholas Mc Guire , Richard Sandiford , David Daney , Adam Nemet , Patrik Kluba In-Reply-To: <20091102214351.GI4880@nowhere> References: <2f73eae542c47ac5bbb9f7280e6c0271d193e90d.1256483735.git.wuzhangjin@gmail.com> <3e0c2d7d8b8f196a8153beb41ea7f3cbf42b3d84.1256483735.git.wuzhangjin@gmail.com> <54c417629e91f40b2bbb4e08cda2a4e6527824c0.1256483735.git.wuzhangjin@gmail.com> <29bccff04932e993ecd9f516d8b6dcf84e2ceecf.1256483735.git.wuzhangjin@gmail.com> <72f2270f7b6e01ca7a4cdf4ac8c21778e5d9652f.1256483735.git.wuzhangjin@gmail.com> <6140dd8f4e1783e5ac30977cf008bb98e4698322.1256483735.git.wuzhangjin@gmail.com> <49b3c441a57f4db423732f81432a3450ccb3240e.1256483735.git.wuzhangjin@gmail.com> <1256550156.5642.148.camel@falcon> <20091102214351.GI4880@nowhere> Content-Type: text/plain; charset="UTF-8" Organization: DSLab, Lanzhou University, China Date: Mon, 09 Nov 2009 12:31:12 +0800 Message-ID: <1257741072.3451.27.camel@falcon.domain.org> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Mon, 2009-11-02 at 22:43 +0100, Frederic Weisbecker wrote: [...] > > > > > > But I would rather see a __mips_notrace on these two core functions. > > > > What about this: __arch_notrace? If the arch need this, define it, > > otherwise, ignore it! if only graph tracer need it, define it in "#ifdef > > CONFIG_FUNCTION_GRAPH_TRACER ... #endif". > > > > The problem is that archs may want to disable tracing on different > places. > For example mips wants to disable tracing in timecounter_read_delta, > but another arch may want to disable tracing somewhere else. > > We'll then have several unrelated __arch_notrace. One that is relevant > for mips, another that is relevant for arch_foo, but all of them will > apply for all arch that have defined a __arch_notrace. > > It's true that __mips_notrace is not very elegant as it looks like > a specific arch annotation intruder. > > > But at least that gives us a per arch filter granularity. > > If only static ftrace could disappear, we could keep only dynamic > ftrace and we would then be able to filter dynamically. > But I'm not sure it's a good idea for archs integration. > I think if we use something like __mips_notrace here, we may get lots of __ARCH_notraces here too, 'Cause some other platforms(at least, as I know, Microblaze will do it too) may also need to add one here, it will become: __mips_notrace __ARCH1_notrace __ARCH2_notrace .... foo() {...} A little ugly ;) and If a new platform need it's __ARCH_notrace, they need to touch the common part of ftrace, more side-effects! but with __arch_notrace, the archs only need to touch it's own part, Although there is a side-effect as you mentioned above ;) So, what should we do? Regards, Wu Zhangjin