Messages in this thread | | | Date | Fri, 7 Jan 2011 17:58:43 +0100 | From | Ingo Molnar <> | Subject | Re: [RFC PATCH 1/2] x86: Fix rbp saving in pt_regs on irq entry |
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* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> On Fri, Jan 07, 2011 at 04:13:58PM +0000, Jan Beulich wrote: > > >>> On 07.01.11 at 17:05, Frederic Weisbecker <fweisbec@gmail.com> wrote: > > > Once I'll have perf callchain based on CFI ready, we'll perhaps find some > > > issues > > > there. Although I guess there are already tools that can make use of that. > > > > Is this to read that you're planning to do a re-spin of the CFI > > unwinding code (which I'm not allowed to submit another time, > > but which we've been using for years in SuSE distros) then? > > An in-kernel CFI unwinder? > > No the intended CFI unwinding that I'm working on for perf is made > on post-processing, on top of partial stack and regs snapshots. > > The true unwinding is computed in userspace.
I think that design will be fundamentally more robust and more flexible than an in-kernel unwinder.
Thanks,
Ingo
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