Messages in this thread | | | Date | Mon, 17 Nov 2008 16:24:34 +0100 | From | Andi Kleen <> | Subject | Re: Oprofile : need to adjust PC by 16 bytes |
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On Mon, Nov 17, 2008 at 04:02:19PM +0100, stephane eranian wrote:
Thanks for explaining it better than I could.
Just a minor correction.
> But it can be very large when overflow happens > during a kernel critical section > where interrupts are off.
Actually oprofile uses the NMI to avoid that particular problem. It still has limits, e.g. no profiling of SMM sections.
> There is nothing SW can do about all of this.
Yes profiling on a out of order machine is hard.
> Furthermore, PEBS can record samples while > in kernel critical sections.
Again with oprofile that works too without PEBS.
-Andi
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