Re: [PATCH v8 12/14] x86: perf: intel_pt: Intel PT PMU driver

[Alexander Shishkin]

Peter Zijlstra <peterz@xxxxxxxxxxxxx> writes:

> On Fri, Nov 14, 2014 at 03:43:45PM +0200, Alexander Shishkin wrote:
>> +static void pt_event_stop(struct perf_event *event, int mode)
>> +{
>> +	struct pt *pt = this_cpu_ptr(&pt_ctx);
>> +
>> +	ACCESS_ONCE(pt->handle_nmi) = 0;
>
> Why is this needed? Will the hardware still generate interrupts if you
> stop the PT thing?

It's meant to serialize nmi handler against the pmu:: callbacks, but now
you mentioned it, it looks very much redundant.

Cheers,
--
Alex
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