Re: Kernel and ADM hardware roulette ( was AMD graphics performance regression in 4.15 and later )

From: Christian KÃnig
Date: Fri Jun 08 2018 - 02:53:14 EST

Am 08.06.2018 um 08:02 schrieb Christoph Hellwig:
On Thu, Jun 07, 2018 at 02:32:46PM +0200, Gabriel C wrote:
Ok done.. bisect points to:
What is the failure mode you are seeing? Can't find anything in the
mail unfortunately.

As far as I analyzed it we now get an -ENOMEM from dma_alloc_attrs() in drivers/gpu/drm/ttm/ttm_page_alloc_dma.c when IOMMU is enabled.

Still need to figure out which parameters we want to use for the allocation, but I think it is only 4k or 8k.