Date: Fri, 9 Sep 2005 11:45:27 +0100 (BST)
From: Hugh Dickins <hugh@veritas.com>
To: Jan Beulich <JBeulich@novell.com>
cc: Andi Kleen <ak@suse.de>, linux-kernel@vger.kernel.org, discuss@x86-64.org
Subject: Re: [discuss] [PATCH] allow CONFIG_FRAME_POINTER for x86-64
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On Fri, 9 Sep 2005, Jan Beulich wrote:
> > But why would anyone want frame pointers on x86-64?
> 
> I'd put the question differently: Why should x86-64 not allow what
> other architectures do?
> 
> But of course, I'm not insisting on this patch to get in, it just
> seemed an obvious inconsistency...

I'm with Jan on this.  I use a similar patch for frame pointers on
x86_64 most of the time, in the hope of getting more accurate backtraces.

Is x86_64 somehow more likely to give you a less noisy backtrace than
i386?  Fewer of those stale return addresses from earlier trips down
the stack?

Frame pointers are imperfect on all(?) the supported architectures,
but I can't see any good reason to exclude them from x86_64.  Just a
couple of weeks ago LKML had a bug where enabling frame pointers on
x86_64 helped Ingo to pinpoint the origin of the problem.

Hugh
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