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

H. Peter Anvin
2009-06-16T01:32:33Z

Mathieu Desnoyers wrote:
>
> Where is the kernel page fault handler grabbing any lock to service
> in-kernel page faults exactly ?
>
> Those are usually considered as utterly simple page table fixups,
> nothing more.
>

It doesn't, *because it doesn't have to*. Your proposal requires that
page faults can be handled inside the page fault handler, and that's a
pretty tall order.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.