On 2024/3/21 22:24, Matthew Wilcox (Oracle) wrote:
> For compound pages which are at least order-2 (and hence have a
> deferred_list), initialise it and then we can check at free that the
> page is not part of a deferred list. We recently found this useful to
> rule out a source of corruption.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/huge_memory.c | 2 --
> mm/hugetlb.c | 3 ++-
> mm/internal.h | 2 ++
> mm/memcontrol.c | 2 ++
> mm/page_alloc.c | 9 +++++----
> 5 files changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 9859aa4f7553..04fb994a7b0b 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -792,8 +792,6 @@ void folio_prep_large_rmappable(struct folio *folio)
> {
> if (!folio || !folio_test_large(folio))
> return;
> - if (folio_order(folio) > 1)
> - INIT_LIST_HEAD(&folio->_deferred_list);
> folio_set_large_rmappable(folio);
> }
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 23ef240ba48a..7e9a766059aa 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1796,7 +1796,8 @@ static void __update_and_free_hugetlb_folio(struct hstate *h,
> destroy_compound_gigantic_folio(folio, huge_page_order(h));
> free_gigantic_folio(folio, huge_page_order(h));
> } else {
> - __free_pages(&folio->page, huge_page_order(h));
> + INIT_LIST_HEAD(&folio->_deferred_list);
Will it be better to add a comment to explain why INIT_LIST_HEAD is needed ?
> + folio_put(folio);
Can all __free_pages be replaced with folio_put in mm/hugetlb.c?
Thanks.
