From e591ef7d96d6ea249916f351dc26a636e565c635 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Mon, 24 Oct 2022 15:20:09 +0900 Subject: [PATCH] mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage Patch series "mm, hwpoison: improve handling workload related to hugetlb and memory_hotplug", v7. This patchset tries to solve the issue among memory_hotplug, hugetlb and hwpoison. In this patchset, memory hotplug handles hwpoison pages like below: - hwpoison pages should not prevent memory hotremove, - memory block with hwpoison pages should not be onlined. This patch (of 4): HWPoisoned page is not supposed to be accessed once marked, but currently such accesses can happen during memory hotremove because do_migrate_range() can be called before dissolve_free_huge_pages() is called. Clear HPageMigratable for hwpoisoned hugepages to prevent them from being migrated. This should be done in hugetlb_lock to avoid race against isolate_hugetlb(). get_hwpoison_huge_page() needs to have a flag to show it's called from unpoison to take refcount of hwpoisoned hugepages, so add it. [naoya.horiguchi@linux.dev: remove TestClearHPageMigratable and reduce to test and clear separately] Link: https://lkml.kernel.org/r/20221025053559.GA2104800@ik1-406-35019.vs.sakura.ne.jp Link: https://lkml.kernel.org/r/20221024062012.1520887-1-naoya.horiguchi@linux.dev Link: https://lkml.kernel.org/r/20221024062012.1520887-2-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Reported-by: Miaohe Lin Reviewed-by: Oscar Salvador Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: Jane Chu Cc: Mike Kravetz Cc: Muchun Song Cc: Yang Shi Signed-off-by: Andrew Morton --- include/linux/hugetlb.h | 10 ++++++---- include/linux/mm.h | 6 ++++-- mm/hugetlb.c | 9 +++++---- mm/memory-failure.c | 21 +++++++++++++++++---- 4 files changed, 32 insertions(+), 14 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 20a0d5a08395..65ea34022aa2 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -183,8 +183,9 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to, long hugetlb_unreserve_pages(struct inode *inode, long start, long end, long freed); int isolate_hugetlb(struct page *page, struct list_head *list); -int get_hwpoison_huge_page(struct page *page, bool *hugetlb); -int get_huge_page_for_hwpoison(unsigned long pfn, int flags); +int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison); +int get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared); void putback_active_hugepage(struct page *page); void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason); void free_huge_page(struct page *page); @@ -391,12 +392,13 @@ static inline int isolate_hugetlb(struct page *page, struct list_head *list) return -EBUSY; } -static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb) +static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison) { return 0; } -static inline int get_huge_page_for_hwpoison(unsigned long pfn, int flags) +static inline int get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { return 0; } diff --git a/include/linux/mm.h b/include/linux/mm.h index f6d2d2d9e284..e2ac6fff03a8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3277,9 +3277,11 @@ extern void shake_page(struct page *p); extern atomic_long_t num_poisoned_pages __read_mostly; extern int soft_offline_page(unsigned long pfn, int flags); #ifdef CONFIG_MEMORY_FAILURE -extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags); +extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared); #else -static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) +static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { return 0; } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index fc8908d715d6..fdb36afea2b2 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7265,7 +7265,7 @@ unlock: return ret; } -int get_hwpoison_huge_page(struct page *page, bool *hugetlb) +int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison) { int ret = 0; @@ -7275,7 +7275,7 @@ int get_hwpoison_huge_page(struct page *page, bool *hugetlb) *hugetlb = true; if (HPageFreed(page)) ret = 0; - else if (HPageMigratable(page)) + else if (HPageMigratable(page) || unpoison) ret = get_page_unless_zero(page); else ret = -EBUSY; @@ -7284,12 +7284,13 @@ int get_hwpoison_huge_page(struct page *page, bool *hugetlb) return ret; } -int get_huge_page_for_hwpoison(unsigned long pfn, int flags) +int get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { int ret; spin_lock_irq(&hugetlb_lock); - ret = __get_huge_page_for_hwpoison(pfn, flags); + ret = __get_huge_page_for_hwpoison(pfn, flags, migratable_cleared); spin_unlock_irq(&hugetlb_lock); return ret; } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 13594556146c..4fff0b36c61d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1244,7 +1244,7 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) int ret = 0; bool hugetlb = false; - ret = get_hwpoison_huge_page(head, &hugetlb); + ret = get_hwpoison_huge_page(head, &hugetlb, false); if (hugetlb) return ret; @@ -1334,7 +1334,7 @@ static int __get_unpoison_page(struct page *page) int ret = 0; bool hugetlb = false; - ret = get_hwpoison_huge_page(head, &hugetlb); + ret = get_hwpoison_huge_page(head, &hugetlb, true); if (hugetlb) return ret; @@ -1785,7 +1785,8 @@ void hugetlb_clear_page_hwpoison(struct page *hpage) * -EBUSY - the hugepage is busy (try to retry) * -EHWPOISON - the hugepage is already hwpoisoned */ -int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) +int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { struct page *page = pfn_to_page(pfn); struct page *head = compound_head(page); @@ -1815,6 +1816,15 @@ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) goto out; } + /* + * Clearing HPageMigratable for hwpoisoned hugepages to prevent them + * from being migrated by memory hotremove. + */ + if (count_increased && HPageMigratable(head)) { + ClearHPageMigratable(head); + *migratable_cleared = true; + } + return ret; out: if (count_increased) @@ -1834,10 +1844,11 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb struct page *p = pfn_to_page(pfn); struct page *head; unsigned long page_flags; + bool migratable_cleared = false; *hugetlb = 1; retry: - res = get_huge_page_for_hwpoison(pfn, flags); + res = get_huge_page_for_hwpoison(pfn, flags, &migratable_cleared); if (res == 2) { /* fallback to normal page handling */ *hugetlb = 0; return 0; @@ -1861,6 +1872,8 @@ retry: if (hwpoison_filter(p)) { hugetlb_clear_page_hwpoison(head); + if (migratable_cleared) + SetHPageMigratable(head); unlock_page(head); if (res == 1) put_page(head);