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?
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> ---
> mm/hugetlb_vmemmap.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> index c3b3fc041903..7bb749a3eea2 100644
> --- a/mm/hugetlb_vmemmap.c
> +++ b/mm/hugetlb_vmemmap.c
> @@ -671,7 +671,8 @@ void __init hugetlb_vmemmap_init(struct hstate *h)
> unsigned int order = huge_page_order(h);
> unsigned int vmemmap_pages;
>
> - if (hugetlb_free_vmemmap_disabled) {
> + if (hugetlb_free_vmemmap_disabled ||
> + !is_power_of_2(sizeof(struct page))) {
> pr_info("disable free vmemmap pages for %s\n", h->name);
> return;
> }
> --
> 2.11.0
>
--
Michal Hocko
SUSE Labs
