Re: [PATCH] mm/cma: convert cma_alloc() to return folio

[Matthew Wilcox]

On Tue, Feb 27, 2024 at 10:13:38AM -0800, Jianfeng Wang wrote:
> Change cma_alloc() to return struct folio. This further increases the
> usage of folios in mm/hugetlb.

I love the idea, but I don't think this works.  The memory returned
from cma_alloc() isn't set up to be a folio, is it?  That is, it
doesn't have compound_head initialised so that page_folio() on
consecutive pages will return the same pointer.

Or have I misunderstood?