[igt-dev] ✗ Fi.CI.IGT: failure for tests/perf_pmu: Avoid off-lining all CPUs

[Tvrtko Ursulin]

On 19/02/2018 16:07, Chris Wilson wrote:
> Quoting Patchwork (2018-02-19 15:55:19)
>> Test perf_pmu:
>>          Subgroup cpu-hotplug:
>>                  incomplete -> SKIP       (shard-apl) fdo#104965
>>          Subgroup other-read-1:
>>                  pass       -> FAIL       (shard-apl)
> 
> I guess that's the expected fallout from deciding to skip after trying
> to offline a cpu.

Kind of expected because I am not quite sure why it behaves differently 
from the existing code which has igt_assert on the write. Maybe I am 
particularly blind today.

> I also guess that makes it a no-go (without some tweaking) if we cause
> random fallout in subsequent tests, i.e. unpredictable flip-flops.

Yep agreed 100%.

Sounds like a case for igt_fail2 = please reboot me, or igt_wedge_machine.

A bit lighter weight, but with weaker coverage, maybe adding 
i915.debug_pmu_cpu=N modparam (present only when I915_DEBUG is set), and 
living with not testing the cpu0 offline paths?

Regards,

Tvrtko