Re: [tip:perfcounters/core] perf_counter: x86: Fix call-chain support to use NMI-safe methods

H. Peter Anvin
2009-06-15T19:22:41Z

Avi Kivity wrote:
> On 06/15/2009 10:02 PM, Peter Zijlstra wrote:
>> Ah, well, I have no idea who expensive cr2 is, if its like a regular
>> register then it should be fine. If however its tons more expensive then
>> we should really avoid it.
>
> IIRC it's pretty cheap, I measured it once when tuning the kvm context
> switch code. I don't recall the exact numbers.
>

Sounds like a win to me.

-hpa