Re: [PATCH v5 21/21] mm/hugetlb: Disable freeing vmemmap if struct page size is not power of two

[Mike Rapoport]

On Fri, Nov 20, 2020 at 10:15:30AM +0100, David Hildenbrand wrote:
> On 20.11.20 09:25, Michal Hocko wrote:
> > On Fri 20-11-20 14:43:25, Muchun Song wrote:
> > > We only can free the unused vmemmap to the buddy system when the
> > > size of struct page is a power of two.
> > 
> > Can we actually have !power_of_2 struct pages?
> 
> AFAIK multiples of 8 bytes (56, 64, 72) are possible.

Or multiples of 4 for 32-bit (28, 32, 36). 
 
> -- 
> Thanks,
> 
> David / dhildenb
> 
> 

-- 
Sincerely yours,
Mike.