[igt-dev] [PATCH i-g-t 2/3] tests/perf_pmu: More busy measurement tightening

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-02-01 12:47:45)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Where we use measured sleeps, take PMU samples immediately before and
> after and look at their delta in order to minimize the effect of any
> test setup delays.

The system and pmu were meant to be idle at the start of the test,
right? So val should always be zero?
-Chris