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

H. Peter Anvin
2009-06-15T21:43:19Z

Mathieu Desnoyers wrote:
>
> As the maintainer of the out-of-tree LTTng tracer, which hooks in the
> page fault handler with tracepoints, and which can build almost entirely
> as modules, I am very tempted to argue that having the nmi-code entirely
> robust wrt in-kernel page faults would be a very-nice-to-have feature.
>

I doubt that is ever going to be reliable, due to reentrancy issues.

-hpa