On 05/17/23 16:09, Jiaqi Yan wrote:
> Adds the functionality to search a subpage's corresponding raw_hwp_page
> in hugetlb page's HWPOISON list. This functionality can also tell if a
> subpage is a raw HWPOISON page.
>
> Exports this functionality to be immediately used in the read operation
> for hugetlbfs.
>
> Signed-off-by: Jiaqi Yan <jiaqiyan@xxxxxxxxxx>
> ---
> include/linux/mm.h | 23 +++++++++++++++++++++++
> mm/memory-failure.c | 26 ++++++++++++++++----------
> 2 files changed, 39 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 27ce77080c79..f191a4119719 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
Any reason why you decided to add the following to linux/mm.h instead of
linux/hugetlb.h? Since it is hugetlb specific I would have thought
hugetlb.h was more appropriate.
> @@ -3683,6 +3683,29 @@ enum mf_action_page_type {
> */
> extern const struct attribute_group memory_failure_attr_group;
>
> +#ifdef CONFIG_HUGETLB_PAGE
> +/*
> + * Struct raw_hwp_page represents information about "raw error page",
> + * constructing singly linked list from ->_hugetlb_hwpoison field of folio.
> + */
> +struct raw_hwp_page {
> + struct llist_node node;
> + struct page *page;
> +};
> +
> +static inline struct llist_head *raw_hwp_list_head(struct folio *folio)
> +{
> + return (struct llist_head *)&folio->_hugetlb_hwpoison;
> +}
> +
> +/*
> + * Given @subpage, a raw page in a hugepage, find its location in @folio's
> + * _hugetlb_hwpoison list. Return NULL if @subpage is not in the list.
> + */
> +struct raw_hwp_page *find_raw_hwp_page(struct folio *folio,
> + struct page *subpage);
> +#endif
> +
> #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
> extern void clear_huge_page(struct page *page,
> unsigned long addr_hint,
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5b663eca1f29..c49e6c2d1f07 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1818,18 +1818,24 @@ EXPORT_SYMBOL_GPL(mf_dax_kill_procs);
> #endif /* CONFIG_FS_DAX */
>
> #ifdef CONFIG_HUGETLB_PAGE
> -/*
> - * Struct raw_hwp_page represents information about "raw error page",
> - * constructing singly linked list from ->_hugetlb_hwpoison field of folio.
> - */
> -struct raw_hwp_page {
> - struct llist_node node;
> - struct page *page;
> -};
>
> -static inline struct llist_head *raw_hwp_list_head(struct folio *folio)
> +struct raw_hwp_page *find_raw_hwp_page(struct folio *folio,
> + struct page *subpage)
> {
> - return (struct llist_head *)&folio->_hugetlb_hwpoison;
> + struct llist_node *t, *tnode;
> + struct llist_head *raw_hwp_head = raw_hwp_list_head(folio);
> + struct raw_hwp_page *hwp_page = NULL;
> + struct raw_hwp_page *p;
> +
> + llist_for_each_safe(tnode, t, raw_hwp_head->first) {
IIUC, in rare error cases a hugetlb page can be poisoned WITHOUT a
raw_hwp_list. This is indicated by the hugetlb page specific flag
RawHwpUnreliable or folio_test_hugetlb_raw_hwp_unreliable().
Looks like this routine does not consider that case. Seems like it should
always return the passed subpage if folio_test_hugetlb_raw_hwp_unreliable()
is true?
--
Mike Kravetz
> + p = container_of(tnode, struct raw_hwp_page, node);
> + if (subpage == p->page) {
> + hwp_page = p;
> + break;
> + }
> + }
> +
> + return hwp_page;
> }
>
> static unsigned long __folio_free_raw_hwp(struct folio *folio, bool move_flag)
> --
> 2.40.1.606.ga4b1b128d6-goog
>
