On Thu, 20 May 2021 10:59:49 +0800 Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote:
> Since commit d6995da31122 ("hugetlb: use page.private for hugetlb specific
> page flags") converts page.private for hugetlb specific page flags. We
> should use hugetlb_page_subpool() to get the subpool pointer instead of
> page_private(). The commit forgot to update it in the page migration
> routine. So fix it.
>
> ...
>
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1290,7 +1290,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
> * page_mapping() set, hugetlbfs specific move page routine will not
> * be called and we could leak usage counts for subpools.
> */
> - if (page_private(hpage) && !page_mapping(hpage)) {
> + if (hugetlb_page_subpool(hpage) && !page_mapping(hpage)) {
> rc = -EBUSY;
> goto out_unlock;
> }
So it uses the wrong page*, so this isn't just a cosmetic fix. One
cannot tell from this changelog.
Please describe the runtime effects of this bug. Please always include
this information when fixing bugs. And when adding them.
