Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754583AbZJURXc (ORCPT ); Wed, 21 Oct 2009 13:23:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754463AbZJURXb (ORCPT ); Wed, 21 Oct 2009 13:23:31 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:35608 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753958AbZJURXb (ORCPT ); Wed, 21 Oct 2009 13:23:31 -0400 Subject: Re: [PATCH -v4 9/9] tracing: add function graph tracer support for MIPS From: Steven Rostedt Reply-To: rostedt@goodmis.org To: David Daney Cc: Wu Zhangjin , linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, Thomas Gleixner , Ralf Baechle , Nicholas Mc Guire In-Reply-To: <4ADF3FE0.5090104@caviumnetworks.com> References: <028867b99ec532b84963a35e7d552becc783cafc.1256135456.git.wuzhangjin@gmail.com> <2f73eae542c47ac5bbb9f7280e6c0271d193e90d.1256135456.git.wuzhangjin@gmail.com> <3f0d3515f74a58f4cfd11e61b62a129fdc21e3a7.1256135456.git.wuzhangjin@gmail.com> <96110ea5dd4d3d54eb97d0bb708a5bd81c7a50b5.1256135456.git.wuzhangjin@gmail.com> <5dda13e8e3a9c9dba4bb7179183941bda502604f.1256135456.git.wuzhangjin@gmail.com> <53bdfdd95ec4fa00d4cc505bb5972cf21243a14d.1256135456.git.wuzhangjin@gmail.com> <1256141540.18347.3118.camel@gandalf.stny.rr.com> <4ADF38D5.9060100@caviumnetworks.com> <1256143568.18347.3169.camel@gandalf.stny.rr.com> <4ADF3FE0.5090104@caviumnetworks.com> Content-Type: text/plain Organization: Kihon Technologies Inc. Date: Wed, 21 Oct 2009 13:23:33 -0400 Message-Id: <1256145813.18347.3210.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1006 Lines: 29 On Wed, 2009-10-21 at 10:07 -0700, David Daney wrote: > I have not used -pg, so I don't know for sure, I think all it does is > add the calls to _mcount. Someone could investigate > -fno-omit-frame-pointer, with that you may be able to use: Note, -pg assumes -fno-omit-frame-pointer, since -fomit-frame-pointer and -pg are incompatible. > > move s8,sp > > To identify function prologs, but it would still be ad hoc, as modern > versions of GCC will reorder instructions in the prolog for better > scheduling. I'll have to search the ABI documentation about calling _mcount in MIPS. There are assumptions with _mcount that are made. It may very well be safe to assume that the move s8,sp will always be there before an mcount call. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/