Re: [PATCH 2/9] dma-direct: reject highmem pages from dma_alloc_from_contiguous

From: Christoph Hellwig
Date: Sat Dec 01 2018 - 11:57:20 EST


On Fri, Nov 30, 2018 at 07:04:51PM +0000, Robin Murphy wrote:
> On 05/11/2018 12:19, Christoph Hellwig wrote:
>> dma_alloc_from_contiguous can return highmem pages depending on the
>> setup, which a plain non-remapping DMA allocator can't handle. Detect
>> this case and try the normal page allocator instead.
>
> ...except the actual implementation is "Detect this case and fail the
> entire allocation if so".

True, that actually changed from when I wrote the commit log due to
some layer issues. I'll update the commit log.