[PATCH v7 4/4] drm/i915: Allow user to set cache at BO creation

[Tvrtko Ursulin]

On 12/05/2023 20:54, Jordan Justen wrote:
> On 2023-05-10 15:14:16, Andi Shyti wrote:
>> Hi,
>>
>> On Tue, May 09, 2023 at 09:59:42AM -0700, fei.yang at intel.com wrote:
>>> From: Fei Yang <fei.yang at intel.com>
>>>
>>> To comply with the design that buffer objects shall have immutable
>>> cache setting through out their life cycle, {set, get}_caching ioctl's
>>> are no longer supported from MTL onward. With that change caching
>>> policy can only be set at object creation time. The current code
>>> applies a default (platform dependent) cache setting for all objects.
>>> However this is not optimal for performance tuning. The patch extends
>>> the existing gem_create uAPI to let user set PAT index for the object
>>> at creation time.
>>> The new extension is platform independent, so UMD's can switch to using
>>> this extension for older platforms as well, while {set, get}_caching are
>>> still supported on these legacy paltforms for compatibility reason.
>>>
>>> Cc: Chris Wilson <chris.p.wilson at linux.intel.com>
>>> Cc: Matt Roper <matthew.d.roper at intel.com>
>>> Cc: Andi Shyti <andi.shyti at linux.intel.com>
>>> Signed-off-by: Fei Yang <fei.yang at intel.com>
>>> Reviewed-by: Andi Shyti <andi.shyti at linux.intel.com>
>>
>> just for a matter of completeness, this is new uapi is tested
>> through the "create-ext-set-pat" test case from the "gem_create"
>> igt test[1]. Can any of the igt maintainers give it a look,
>> comment and ack?
>>
>> The mesa merge request is here [2]. As there is a merge request
>> in progress, would anyone from mesa be so kind to give an ack to
>> this patch, as well?
>>
>> With the mesa ack in place this patch should be ready to go and
>> I'm looking forward to having it in.
> 
> I tested my MR [2] in our CI. There was some bad news, but I don't
> think it needs to block these patches.
> 
> The good news was that I found that OpenGL testing with our iris
> driver appeared to have ok results when using this interface.
> 
> But, our Vulkan Anvil driver was not stable with the current patches
> in the Mesa MR. We will need to debug this further before using the
> interface on Vulkan.
> 
> I don't suspect that this is an issue with the kernel interface, so
> you can add:
> 
> Tested-by: Jordan Justen <jordan.l.justen at intel.com>

I had a browse through the Mesa merge request and it looks all r-b-ed to 
me. To confirm - it will get merged when we merge the i915 half?

Could you also give an a-b for the i915 patch please?

Regards,

Tvrtko