Messages in this thread | | | Date | Mon, 15 Jun 2009 20:47:14 +0200 | From | Ingo Molnar <> | Subject | Re: [tip:perfcounters/core] perf_counter: x86: Fix call-chain support to use NMI-safe methods |
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* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> > If it's a slowdown then the decision is easy: we dont want this, > > we want to push the overhead into the sampling code, away from > > common codepaths. > > I did not try to make the "hand unroll + ret" the default. I > therefore don't know if it is faster or slower than iret. But I > prefered to stay on the safe side and only modify the exceptions > nested within NMI handlers.
hm, i misread that bit then. Too bad.
Btw., that speedup question is still valid. (Just not relevant here and now.)
Ingo
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