[Mesa-dev] [PATCH 00/14] RadeonSI: SDMA texture copy rewrite

[Alex Deucher]

On Wed, May 4, 2016 at 7:43 PM, Marek Olšák <maraeo at gmail.com> wrote:
> Hi,
>
> This patch series completely rewrites texture copying with SDMA for CIK & VI. It only uses the "partial" copy packets, which makes it a lot simpler (one packet per layered/3D copy). Most of the complexity is in handling hw limitations, but luckily the SDMA path can be used in the majority of cases.
>
> On top of that, the DMA IB support is improved thanks to extensive testing and benchmarking.
>
> This is only enabled on VI for now. It can be enabled on CIK after enough testing is done.
>
> There is one more hardware limitation that can cause VM faults with T2L copies and needs a workaround. The exact workaround is still under discussion, but I think this is good enough for review already.
>
> On Tonga, it beats the 3D engine in texture upload performance by 0-80%. On APUs, the performance is mixed or slightly worse. The reason may be that the 3D engine uses less bandwidth thanks to DCC.
>
> The fact that SDMA can't do DCC compression can be detrimental to texturing performance on VI. The impact hasn't been measured yet.
>
> Texture uploads still use 2 copies (user memory -> linear, linear -> tiled). Merging those 2 copies into 1 is not done in this series.
>
> Please review and opinions on the DCC issue are welcome,

Have you looked at using SDMA for buffer clears as well?

Patches are:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

>
> Marek
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