[PATCH v17 5/9] mm: hugetlb: set the PageHWPoison to the raw error page
From: Muchun Song <hidden>
Date: 2021-02-25 13:27:12
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
hugetlb subsystem, memory management, the rest · Maintainers:
Muchun Song, Oscar Salvador, Andrew Morton, Linus Torvalds
Because we reuse the first tail vmemmap page frame and remap it with read-only, we cannot set the PageHWPosion on some tail pages. So we can use the head[4].private (There are at least 128 struct page structures associated with the optimized HugeTLB page, so using head[4].private is safe) to record the real error page index and set the raw error page PageHWPoison later. Signed-off-by: Muchun Song <redacted> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Rientjes <rientjes@google.com> --- mm/hugetlb.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 72 insertions(+), 8 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b6e4e3f31ad2..bccb6907833f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -1304,6 +1304,74 @@ static inline void destroy_compound_gigantic_page(struct page *page, unsigned int order) { } #endif +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP +static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head) +{ + struct page *page; + + if (!PageHWPoison(head) || !free_vmemmap_pages_per_hpage(h)) + return; + + page = head + page_private(head + 4); + + /* + * Move PageHWPoison flag from head page to the raw error page, + * which makes any subpages rather than the error page reusable. + */ + if (page != head) { + SetPageHWPoison(page); + ClearPageHWPoison(head); + } +} + +static inline void hwpoison_subpage_set(struct hstate *h, struct page *head, + struct page *page) +{ + if (!PageHWPoison(head)) + return; + + if (free_vmemmap_pages_per_hpage(h)) { + set_page_private(head + 4, page - head); + } else if (page != head) { + /* + * Move PageHWPoison flag from head page to the raw error page, + * which makes any subpages rather than the error page reusable. + */ + SetPageHWPoison(page); + ClearPageHWPoison(head); + } +} + +static inline void hwpoison_subpage_clear(struct hstate *h, struct page *head) +{ + if (!PageHWPoison(head) || !free_vmemmap_pages_per_hpage(h)) + return; + + set_page_private(head + 4, 0); +} +#else +static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head) +{ +} + +static inline void hwpoison_subpage_set(struct hstate *h, struct page *head, + struct page *page) +{ + if (PageHWPoison(head) && page != head) { + /* + * Move PageHWPoison flag from head page to the raw error page, + * which makes any subpages rather than the error page reusable. + */ + SetPageHWPoison(page); + ClearPageHWPoison(head); + } +} + +static inline void hwpoison_subpage_clear(struct hstate *h, struct page *head) +{ +} +#endif + static int update_and_free_page(struct hstate *h, struct page *page) __releases(&hugetlb_lock) __acquires(&hugetlb_lock) {
@@ -1357,6 +1425,8 @@ static int update_and_free_page(struct hstate *h, struct page *page) return -ENOMEM; } + hwpoison_subpage_deliver(h, page); + for (i = 0; i < pages_per_huge_page(h); i++, subpage = mem_map_next(subpage, page, i)) { subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
@@ -1801,14 +1871,7 @@ int dissolve_free_huge_page(struct page *page) goto retry; } - /* - * Move PageHWPoison flag from head page to the raw error page, - * which makes any subpages rather than the error page reusable. - */ - if (PageHWPoison(head) && page != head) { - SetPageHWPoison(page); - ClearPageHWPoison(head); - } + hwpoison_subpage_set(h, head, page); list_del(&head->lru); h->free_huge_pages--; h->free_huge_pages_node[nid]--;
@@ -1818,6 +1881,7 @@ int dissolve_free_huge_page(struct page *page) h->surplus_huge_pages--; h->surplus_huge_pages_node[nid]--; h->max_huge_pages++; + hwpoison_subpage_clear(h, head); } } out:
--
2.11.0