Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763339AbZCYSl3 (ORCPT ); Wed, 25 Mar 2009 14:41:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754345AbZCYSlV (ORCPT ); Wed, 25 Mar 2009 14:41:21 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123]:39592 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753807AbZCYSlU (ORCPT ); Wed, 25 Mar 2009 14:41:20 -0400 Date: Wed, 25 Mar 2009 14:41:16 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Tim Bird cc: Russell King - ARM Linux , =?ISO-8859-15?Q?Uwe_Kleine-K=F6nig?= , Frederic Weisbecker , Abhishek Sagar , linux-arm-kernel , linux kernel , Ingo Molnar Subject: Re: Anyone working on ftrace function graph support on ARM? In-Reply-To: <49CA79FA.8080906@am.sony.com> Message-ID: References: <49C936CA.8070800@am.sony.com> <20090324213618.GC5975@nowhere> <49C95EAF.7030901@gmail.com> <20090324224857.GE5975@nowhere> <20090325084248.GF4697@n2100.arm.linux.org.uk> <49CA5CFF.8090908@am.sony.com> <20090325170533.GA4667@pengutronix.de> <20090325171727.GH2952@n2100.arm.linux.org.uk> <49CA79FA.8080906@am.sony.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1433 Lines: 34 On Wed, 25 Mar 2009, Tim Bird wrote: > Russell King - ARM Linux wrote: > > On Wed, Mar 25, 2009 at 06:05:33PM +0100, Uwe Kleine-K???nig wrote: > >> On Wed, Mar 25, 2009 at 09:34:07AM -0700, Tim Bird wrote: > >>> Russell King - ARM Linux wrote: > >>>> As pointed out in my previous mail, identifying where on the stack the > >>>> return address is stored is only possible for OABI with frame pointers. > >>>> > >>>> EABI will probably be possible with the stack unwinding code, but it > >>>> probably won't be cheap. The EABI unwinder is scheduled for merging > >>>> during the present now-open merge window. > >> EABI with frame pointers should work, too, shouldn't it? > > > > Yes, as I said at the top of my reply dated Wed, 25 Mar 2009 09:57:51 +0000 > > It turns out you can't use -pg and -fomit-frame-pointers at the same time. > At least, my gcc complains about this: > $ make > arm-sony-linux-gnueabi-dev-gcc -g -pg -fomit-frame-pointer -o hello hello.c > arm-sony-linux-gnueabi-dev-gcc: -pg and -fomit-frame-pointer are incompatible > make: *** [hello] Error 1 Correct, that is because mcount requires (as Russell earlier pointed out) the use of frame pointers. -- 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/