Re: [PATCH 7/7] dma-mapping: reject __GFP_COMP in dma_alloc_attrs

Leon Romanovsky
2022-11-16T07:11:22Z

On Wed, Nov 16, 2022 at 07:11:06AM +0100, Christoph Hellwig wrote:
> On Mon, Nov 14, 2022 at 10:11:50AM +0200, Leon Romanovsky wrote:
> > In RDMA patches, you wrote that GFP_USER is not legal flag either. So it
> > is better to WARN here for everything that is not allowed.
>
> So __GFP_COMP is actually problematic and changes behavior, and I plan
> to lift an optimization from the arm code to the generic one that
> only rounds up allocations to the next page size instead of the next
> power of two, so I need this check now. Other flags including
> GFP_USER are pretty bogus to, but I actually need to do a full audit
> before rejecting them, which I've only done for GFP_COMP so far.

ok, let's do it later.

Thanks