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

Mathieu Desnoyers
2009-06-15T22:49:20Z

* H. Peter Anvin (hpa@zytor.com) wrote:
> Mathieu Desnoyers wrote:
> >
> > I'm just thinking that touching or not vmalloc'd areas should not be the
> > first thing that comes into the mind of someone willing to write a
> > nmi-hooking tracer or oprofile module.
> >
>
> But is HAS to be. Otherwise you're in deadlock city anyway.
>

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.

Mathieu

> -hpa
>

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Mathieu Desnoyers
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