Re: [PATCH v3 3/6] mm/hugetlb: add hugetlb_folio_subpool() helper

From: Mike Kravetz
Date: Mon Sep 19 2022 - 18:24:50 EST


On 09/08/22 12:37, Sidhartha Kumar wrote:
> Allows hugetlbfs_migrate_folio to check subpool information by passing
> in a folio.
>
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
> (cherry picked from commit cd9e187858b45b890097cfcd0b2eb4bbbb9a59ae)

??? I think this must have been included by mistake.

> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
> ---
> fs/hugetlbfs/inode.c | 4 ++--
> include/linux/hugetlb.h | 7 ++++++-
> 2 files changed, 8 insertions(+), 3 deletions(-)

I think this and the following patch are simple enough to combine. They
both are dealing with accessing/setting hugetlb subpool info. They already
have the same 'Subject:'. :)

With these fixups,
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
--
Mike Kravetz

>
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index 52d9b390389b..c2e9c0cdbd81 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -1151,9 +1151,9 @@ static int hugetlbfs_migrate_folio(struct address_space *mapping,
> if (rc != MIGRATEPAGE_SUCCESS)
> return rc;
>
> - if (hugetlb_page_subpool(&src->page)) {
> + if (hugetlb_folio_subpool(src)) {
> hugetlb_set_page_subpool(&dst->page,
> - hugetlb_page_subpool(&src->page));
> + hugetlb_folio_subpool(src));
> hugetlb_set_page_subpool(&src->page, NULL);
> }
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 0952ea50251d..1e7c4007386e 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -744,12 +744,17 @@ extern unsigned int default_hstate_idx;
>
> #define default_hstate (hstates[default_hstate_idx])
>
> +static inline struct hugepage_subpool *hugetlb_folio_subpool(struct folio *folio)
> +{
> + return (void *)folio_get_private_1(folio);
> +}
> +
> /*
> * hugetlb page subpool pointer located in hpage[1].private
> */
> static inline struct hugepage_subpool *hugetlb_page_subpool(struct page *hpage)
> {
> - return (void *)page_private(hpage + SUBPAGE_INDEX_SUBPOOL);
> + return hugetlb_folio_subpool(page_folio(hpage));
> }
>
> static inline void hugetlb_set_page_subpool(struct page *hpage,
> --
> 2.31.1
>