Re: [PATCH v2 1/3] perf/core: Add a tracepoint for perf sampling

[Peter Zijlstra]

On Wed, Aug 03, 2016 at 11:57:05AM -0700, Brendan Gregg wrote:

> As for pmu tracepoints: if I were to instrument it (although I wasn't
> planning to), I'd put a tracepoint in perf_event_overflow() called
> "perf:perf_overflow", with the same arguments. That could then be used
> for all PMU overflow events, without needing to add specific
> tracepoints. 

Could we not teach BPF to replace event->overflow_handler and inject
itself there?

We don't currently have nice interfaces for doing that, but it should be
possible to do I think. We already have the indirect function call, so
injecting ourself there has 0 overhead.