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.
