[Mesa-dev] [PATCH] radv: set cb base tile swizzles for MRT speedups (v3)

[Alex Smith]

On 13 July 2017 at 04:35, Dave Airlie <airlied at gmail.com> wrote:
> On 11 July 2017 at 23:49, Alex Smith <asmith at feralinteractive.com> wrote:
>> On 11 July 2017 at 14:27, Alex Smith <asmith at feralinteractive.com> wrote:
>>>
>>> On 10 July 2017 at 05:59, Dave Airlie <airlied at gmail.com> wrote:
>>>>
>>>> From: Dave Airlie <airlied at redhat.com>
>>>>
>>>> This patch uses addrlib to workout the tile swizzles according
>>>> to the surface index. It seems to produce the same values as
>>>> amdgpu-pro for the deferred test.
>>>>
>>>> v2: don't apply swizzle to CMASK. the eg docs don't mention
>>>> it, and we clearly don't align cmask for that.
>>>> v3: disable surf index for dedicated images, as these will
>>>> most likely be shared, and I don't think the metadata has
>>>> space for this info in it yet.
>>>
>>>
>>> FWIW, disabling this for images marked as dedicated means this won't get
>>> any improvements for render targets on our games. We create all render
>>> targets as dedicated when NV_dedicated_allocation is available since this
>>> gets us significant perf improvement on NVIDIA.
>>>
>>> If it's not currently possible to have this enabled for dedicated images
>>> we could avoid using it on AMD, though I'm curious if there's likely to be
>>> any other perf benefits to marking RTs as dedicated we'd then be missing out
>>> on? I've not done any testing to see if there's any benefit from using it.
>>
>>
>> Realised this possibly didn't sound clear - what I'm asking is does using
>> NV_dedicated_allocation give any perf benefit on RADV at all like it does
>> for NV? If not we could avoid it to get the benefits from this patch.
>
> No on radv we really only want dedicated allocation for shared resources
> i.e. external memory ones. I don't think you'd get any speed up from using it.
>
> I'd like to figure out a way to make it work with this feature, but I
> think it means
> enhancing the metadata a bit.

Fair enough, in that case I'll disable our use of the extension on RADV.

Thanks,
Alex