Re: [PATCH v9 10/21] drm/i915: Add engine reset count in get-reset-stats ioctl

Michel Thierry
2017-06-15T21:23:19Z

On 15/06/17 14:14, Chris Wilson wrote:
> Quoting Michel Thierry (2017-06-15 21:18:17)
>> Users/tests relying on the total reset count will start seeing a smaller
>> number since most of the hangs can be handled by engine reset.
>> Note that if reset engine x, context a running on engine y will be unaware
>> and unaffected.
>>
>> To start the discussion, include just a total engine reset count. If it
>> is deemed useful, it can be extended to report each engine separately.
>> Our igt's gem_reset_stats test will need changes to ignore the pad field,
>> since it can now return reset_engine_count.
>>
>> v2: s/engine_reset/reset_engine/, use union in uapi to not break compatibility.
>> v3: Keep rejecting attempts to use pad as input (Antonio)
>
> Nope. You have now defined that pad works as an output-only parameter.
> It is no longer in a state of flux and can be any value on input. The
> test in gem_reset_stats becomes invalid.

Ok, I'll also have to make more changes to that test; the existing
subtests must enforce i915.reset=1 (or read both reset_count and
pad/reset_engine_count).