Messages in this thread | | | Date | Thu, 4 Aug 2016 16:28:53 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2 1/3] perf/core: Add a tracepoint for perf sampling |
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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.
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