Re: [PATCH v2 4/4] mm: cache struct page for empty_zero_page and return it from ZERO_PAGE()

David Hildenbrand (Arm)
2026-02-23T16:20:27Z

On 2/9/26 15:40, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> For most architectures every invocation of ZERO_PAGE() does
> virt_to_page(empty_zero_page). But empty_zero_page is in BSS and it is
> enough to get its struct page once at initialization time and then use
> it whenever a zero page should be accessed.
>
> Add yet another __zero_page variable that will be initialized as
> virt_to_page(empty_zero_page) for most architectures in a weak
> arch_setup_zero_pages() function.
>
> For architectures that use colored zero pages (MIPS and s390) rename their
> setup_zero_pages() to arch_setup_zero_pages() and make it global rather
> than static.
>
> For architectures that cannot use virt_to_page() for BSS (arm64 and
> sparc64) add override of arch_setup_zero_pages().
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Acked-by: David Hildenbrand (Arm) <david@kernel.org>

--
Cheers,

David