Subject: Re: [PATCH 1/2] mm/cma: remove unsupported gfp_mask parameter from cma_alloc()

From: Christoph Hellwig <[email-masked]>
Date: Thu, 12 Jul 2018 09:15:36 +0200

On Thu, Jul 12, 2018 at 11:48:47AM +0900, Joonsoo Kim wrote:
> One of existing user is general DMA layer and it takes gfp flags that is
> provided by user. I don't check all the DMA allocation sites but how do
> you convince that none of them try to use anything other
> than GFP_KERNEL [|__GFP_NOWARN]?

They use a few others things still like __GFP_COMP, __GPF_DMA or
GFP_HUGEPAGE.  But all these are bogus as we have various implementations
that can't respect them.  I plan to get rid of the gfp_t argument
in the dma_map_ops alloc method in a few merge windows because of that,
but it needs further implementation consolidation first.