[PATCH v16 5/9] mm: hugetlb: set the PageHWPoison to the raw error page
From: Muchun Song <hidden>
Date: 2021-02-19 10:55:25
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 | 83 ++++++++++++++++++++++++++++++++++++++++++++++------ mm/hugetlb_vmemmap.c | 12 -------- mm/hugetlb_vmemmap.h | 17 +++++++++++ 3 files changed, 91 insertions(+), 21 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bcf856974c48..f0877411f790 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -1305,6 +1305,74 @@ 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) {
@@ -1351,6 +1419,8 @@ 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++) { page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 1 << PG_dirty |
@@ -1795,22 +1865,17 @@ 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); ClearHPageFreed(page); list_del(&head->lru); h->free_huge_pages--; h->free_huge_pages_node[nid]--; h->max_huge_pages--; rc = update_and_free_page(h, head); - if (rc) + if (rc) { h->max_huge_pages++; + hwpoison_subpage_clear(h, head); + } } out: spin_unlock(&hugetlb_lock);
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 29a3380f3b20..f7ab3d99250a 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c@@ -181,18 +181,6 @@ #define RESERVE_VMEMMAP_NR 2U #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) -/* - * How many vmemmap pages associated with a HugeTLB page that can be freed - * to the buddy allocator. - * - * Todo: Returns zero for now, which means the feature is disabled. We will - * enable it once all the infrastructure is there. - */ -static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) -{ - return 0; -} - static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) { return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT;
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
index e5547d53b9f5..a37771b0b82a 100644
--- a/mm/hugetlb_vmemmap.h
+++ b/mm/hugetlb_vmemmap.h@@ -13,6 +13,18 @@ #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP int alloc_huge_page_vmemmap(struct hstate *h, struct page *head); void free_huge_page_vmemmap(struct hstate *h, struct page *head); + +/* + * How many vmemmap pages associated with a HugeTLB page that can be freed + * to the buddy allocator. + * + * Todo: Returns zero for now, which means the feature is disabled. We will + * enable it once all the infrastructure is there. + */ +static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) +{ + return 0; +} #else static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head) {
@@ -22,5 +34,10 @@ static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head) static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head) { } + +static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) +{ + return 0; +} #endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */ #endif /* _LINUX_HUGETLB_VMEMMAP_H */
--
2.11.0