Re: [PATCH] perf/x86/intel: Drop kernel samples even though :u is specified

From: Jin, Yao
Date: Fri May 19 2017 - 08:06:27 EST


SNIP

I would much rather see this in generic code, somewhere around
__perf_event_overflow() I suppose. That would retain proper accounting
for the interrupt rate etc..

Also it would work for all architectures. Because I'm thinking more than
just x86 will suffer from skid.
Yes, moving to generic code is better. Thanks for the suggestion! I will do that.

If you're really worried, I suppose you can put it behind a PERF_PMU_CAP
flag or something.
I guess what you are suggesting is to add checking like:

if (is_sampling_event(event)) {
if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
return;
}
}

Is my understanding correct?

Thanks
Jin Yao