From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261827AbTKCJ3M (ORCPT ); Mon, 3 Nov 2003 04:29:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261871AbTKCJ3M (ORCPT ); Mon, 3 Nov 2003 04:29:12 -0500 Received: from web40907.mail.yahoo.com ([66.218.78.204]:44102 "HELO web40907.mail.yahoo.com") by vger.kernel.org with SMTP id S261827AbTKCJ3K (ORCPT ); Mon, 3 Nov 2003 04:29:10 -0500 Message-ID: <20031103092909.4955.qmail@web40907.mail.yahoo.com> Date: Mon, 3 Nov 2003 01:29:09 -0800 (PST) From: Bradley Chapman Subject: Re: What do frame pointers do? To: "Randy.Dunlap" Cc: linux-kernel@vger.kernel.org In-Reply-To: <20031102204556.0c5b377a.rddunlap@osdl.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mr. Dunlap, --- "Randy.Dunlap" wrote: > On Sun, 2 Nov 2003 09:00:29 -0800 (PST) Bradley Chapman > wrote: > > | What exactly is the purpose of a frame pointer? As far back as I can remember, > 2.4 > | and 2.6 kernels have supported something called a frame pointer, which slows > down > | the kernel slightly but supposedly outputs 'very useful debugging information.' > | Unfortunately, it doesn't really explain what they are, and for the past few > months, > | I haven't seen any hacker gods asking for CONFIG_FRAME_POINTER=y, except for > Russell > | King, who wants them compiled for ARM processors for some reason (I grepped the > | kernel source looking for answers and found a comment which implied this). > | > | Does anyone know where I can find a good explanation of what they are and what > they > | do? > > Frame pointers enable more deterministic back tracing of the stack, > which can be helpful for tracking down bugs. I build with > CONFIG_FRAME_POINTER enabled all of the time. > > Note, however, that current 2.6.x Makefile does not allow frame pointers > to be used with gcc 2.96 since it has some known problems with code generation > when using frame pointers. > > There is a little discussion of frame pointers in the Intel > IA-32 Intel® Architecture Software Developer;s Manual Volume 1: > Basic Architecture > and > IA-32 Intel® Architecture Software Developer's Manual Volume 2: > Instruction Set Reference, > which are downloadable as .pdf files from developer.intel.com. OK, thanks for explaining it to me. > > -- > ~Randy Brad ===== Brad Chapman Permanent e-mail: kakadu_croc@yahoo.com __________________________________ Do you Yahoo!? Exclusive Video Premiere - Britney Spears http://launch.yahoo.com/promos/britneyspears/