[Mesa-dev] llvmpipe not supporting EGL_EXT_image_dma_buf_import ?

[Irion, Alexander]

Yes, exactly - I would like to use the Docker container as a development/testing environment. Performance would not matter for that. Would be just good to be able to run the same code in Docker, which will later run on the real hardware.
--Alex

-----Ursprüngliche Nachricht-----
Von: Christian König <christian.koenig at amd.com>
Gesendet: Freitag, 29. Oktober 2021 11:43
An: Michel Dänzer <michel at daenzer.net>; Irion, Alexander <Alexander_Irion at mentor.com>; mesa-dev at lists.freedesktop.org
Betreff: Re: [Mesa-dev] llvmpipe not supporting EGL_EXT_image_dma_buf_import ?

Am 29.10.21 um 11:35 schrieb Michel Dänzer:
> On 2021-10-28 14:02, Christian König wrote:
>> Well I'm not an expert on llvmpipe, but as far as I know that's a general problem.
>>
>> DMA-buf is used by the Linux kernel drivers to pass hardware bufefrs between processes and drivers.
>>
>> Since llvmpipe as a software renderer it has no kernel driver, so there is no easy way to implement that.
> Even if there was, CPU reads from dma-bufs imported from a HW driver
> may be extremely slow, so they should be avoided other than for
> specific setups where they're known to be guaranteed to perform
> adequately. (This performance trap is why I think allowing mmap for
> dma-buf fds was a mistake)

Yeah, I'm not very keen of that either.

But for testing I think it would still be nice to have the ability to share DMA-bufs with software rendereres even if it is horrible slow.

Christian.
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