Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030245AbVIILVN (ORCPT ); Fri, 9 Sep 2005 07:21:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030246AbVIILVN (ORCPT ); Fri, 9 Sep 2005 07:21:13 -0400 Received: from ns2.suse.de ([195.135.220.15]:51665 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1030245AbVIILVM (ORCPT ); Fri, 9 Sep 2005 07:21:12 -0400 Date: Fri, 9 Sep 2005 13:21:08 +0200 From: Andi Kleen To: Hugh Dickins Cc: Andi Kleen , Jan Beulich , linux-kernel@vger.kernel.org, discuss@x86-64.org Subject: Re: [discuss] [PATCH] allow CONFIG_FRAME_POINTER for x86-64 Message-ID: <20050909112108.GK19913@wotan.suse.de> References: <43207D28020000780002451E@emea1-mh.id2.novell.com> <4321749202000078000248C5@emea1-mh.id2.novell.com> <200509091258.13300.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1273 Lines: 34 On Fri, Sep 09, 2005 at 12:14:38PM +0100, Hugh Dickins wrote: > > Ah, right. I'm using kdb with it. (And my recollection of when > show_stack did have a framepointer version, is that it was hopelessly > broken on interrupt frames, and we're much better off without it.) Not sure if the x86-64 kdb had code to follow them either. The i386 one has. > > > The only reason to use them would be external debuggers, but those > > don't need them on x86-64 neither. > > Don't need them, but find them as useful on x86_64 as on i386? > > Certainly, I can go on patching in FRAME_POINTERs for x86_64 > as I have done, no problem with that. But it seems both bogus > and unhelpful to have that "&& !X86_64" in lib/Kconfig.debug - > framepointers are as helpful/useless on x86_64 as the rest. The original reason was that they were never enabled because nobody passed -fno-omit-frame-pointer. That was apparently later fixed. But kdb should be using a dwarf2 unwinder instead. kgdb certainly supports that, as does NLKD. -Andi - 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/