Subject: Re: [Xen-devel] Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable

From: Andi Kleen <[email-masked]>
Date: Tue, 20 Mar 2007 22:49:45 +0100

On Tue, Mar 20, 2007 at 09:39:18PM +0000, Alan Cox wrote:
> > > Because that's really the issue: do you want a "pretty" backtrace, or do 
> > > you want one that is rock solid but has some crud in it.
> > 
> > I just want an as exact backtrace as possible. I also think
> > that we can make the unwinder robust enough.
> 
> Any reason you can't put the exact back trace in "[xxx]" and the ones we
> see on the stack which dont look like call trace as ?xxx? It makes the
> code a bit trickier but we depend on the quality of traces

Linus is worried about the unwinder crashing -- that wouldn't help with that.

What the (now out of tree) unwinder does is to check if it finishes
the trace and if not fall back to the old unwinder.

-Andi