[Intel-gfx] [PATCH 01/11] drm/i915/perf: Disable rc6 only while OA is enabled

[Lionel Landwerlin]

On 09/10/2019 23:52, Chris Wilson wrote:
> Quoting Lionel Landwerlin (2019-10-09 21:46:56)
>> Hmm... nope, sorry.
>>
>> We'll loose NOA configuration if you do that.
>> And you'll have to rerun the oa config BO prior to enabling.
> Is that not worth it? Move the enable_metric_set/disable_metric_set to
> i915_perf_enable_locked as well?
> -Chris
>
It takes some time to apply the configuration so not really worth it.
Plus either you do perf queries and as soon as you're finished you 
shutdown OA, or you monitor the whole system and then you just can't 
have RC6 kick in.

The only real use case of those enable/disable ioctl is to reset the 
head/tail register of the OA buffer because data head started 
overwriting the tail.

-Lionel