Re: [patch 1/2] x86_64 page fault NMI-safe

Andi Kleen
2010-07-14T20:07:52Z

> > In fact I'm pretty sure it worked originally. Perhaps it regressed?
>
> I'd first ask the obvious to Perf authors: does perf issue vmalloc_sync_all()
> between percpu data allocation and tracing activation ? The generic ring buffer
> library I posted last week does it already as a precaution for this very
> specific reason (making sure NMIs never trigger page faults).

I suspect the low level per cpu allocation functions should
just call it.

-Andi

--
ak@linux.intel.com -- Speaking for myself only.