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

Jeremy Fitzhardinge
2009-06-15T20:18:32Z

On 06/15/09 12:21, Avi Kivity wrote:
> You can read cr2 on nmi entry and nmi exit, and only write it if it
> has changed (if it turns out that writing cr2 is expensive; ISTR that
> it isn't).
>

Writing the real cr2 is expensive, but it may be cheap to write the
virtual cr2 in a vmx context. Or something.

J