Messages in this thread | | | Date | Mon, 15 Jun 2009 21:07:59 +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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* Ingo Molnar <mingo@elte.hu> wrote:
> > To a point where it cannot afford a simple register save/restore > > ? > > > > There is "caring" and "_caring_". I am tempted to ask what NMI > > handler execution frequency you have in mind here to figure out > > if we are not trying to optimize sub-nanoseconds per minutes. ;) > > I routinely run 'perf' with half a million NMIs per second or > more. ( Why wait 10 seconds for a profile you can get in 1 second? > ;-) > > Granted that is over multiple CPUs - but still performance does > matter here too. > > Reading cr2 is certainly fast. Writing it - dunno.
But one thing is sure: it is certainly going to be faster than the INVLPG(s!) we have to do with the GUP solution.
Ingo
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