[Intel-gfx] [PATCH] drm/i915: Fix context runtime accounting

[Tvrtko Ursulin]

On 31/03/2023 07:25, Matthew Auld wrote:
> On Mon, 20 Mar 2023 at 15:14, Tvrtko Ursulin
> <tvrtko.ursulin at linux.intel.com> wrote:
>>
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> When considering whether to mark one context as stopped and another as
>> started we need to look at whether the previous and new _contexts_ are
>> different and not just requests. Otherwise the software tracked context
>> start time was incorrectly updated to the most recent lite-restore time-
>> stamp, which was in some cases resulting in active time going backward,
>> until the context switch (typically the hearbeat pulse) would synchronise
>> with the hardware tracked context runtime. Easiest use case to observe
>> this behaviour was with a full screen clients with close to 100% engine
>> load.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> Fixes: bb6287cb1886 ("drm/i915: Track context current active time")
>> Cc: <stable at vger.kernel.org> # v5.19+
> 
> Seems reasonable to me, fwiw,
> Reviewed-by: Matthew Auld <matthew.auld at intel.com>

Thanks, pushed!

Regards,

Tvrtko