diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 995c8d65a95c..05407831016b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -924,6 +924,31 @@ struct hstate *size_to_hstate(unsigned long size) return NULL; } +/* + * Test to determine whether the hugepage is "active/in-use" (i.e. being linked + * to hstate->hugepage_activelist.) + * + * This function can be called for tail pages, but never returns true for them. + */ +bool page_huge_active(struct page *page) +{ + VM_BUG_ON_PAGE(!PageHuge(page), page); + return PageHead(page) && PagePrivate(&page[1]); +} + +/* never called for tail page */ +static void set_page_huge_active(struct page *page) +{ + VM_BUG_ON_PAGE(!PageHeadHuge(page), page); + SetPagePrivate(&page[1]); +} + +static void clear_page_huge_active(struct page *page) +{ + VM_BUG_ON_PAGE(!PageHeadHuge(page), page); + ClearPagePrivate(&page[1]); +} + void free_huge_page(struct page *page) { /* @@ -952,6 +977,7 @@ void free_huge_page(struct page *page) restore_reserve = true; spin_lock(&hugetlb_lock); + clear_page_huge_active(page); hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h), page); if (restore_reserve) @@ -2972,6 +2998,7 @@ retry_avoidcopy: copy_user_huge_page(new_page, old_page, address, vma, pages_per_huge_page(h)); __SetPageUptodate(new_page); + set_page_huge_active(new_page); mmun_start = address & huge_page_mask(h); mmun_end = mmun_start + huge_page_size(h); @@ -3084,6 +3111,7 @@ retry: } clear_huge_page(page, address, pages_per_huge_page(h)); __SetPageUptodate(page); + set_page_huge_active(page); if (vma->vm_flags & VM_MAYSHARE) { int err; @@ -3913,19 +3941,26 @@ int dequeue_hwpoisoned_huge_page(struct page *hpage) bool isolate_huge_page(struct page *page, struct list_head *list) { + bool ret = true; + VM_BUG_ON_PAGE(!PageHead(page), page); - if (!get_page_unless_zero(page)) - return false; spin_lock(&hugetlb_lock); + if (!page_huge_active(page) || !get_page_unless_zero(page)) { + ret = false; + goto unlock; + } + clear_page_huge_active(page); list_move_tail(&page->lru, list); +unlock: spin_unlock(&hugetlb_lock); - return true; + return ret; } void putback_active_hugepage(struct page *page) { VM_BUG_ON_PAGE(!PageHead(page), page); spin_lock(&hugetlb_lock); + set_page_huge_active(page); list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); spin_unlock(&hugetlb_lock); put_page(page); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5fd8931d8c31..d9359b770cd9 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1586,8 +1586,18 @@ static int soft_offline_huge_page(struct page *page, int flags) } unlock_page(hpage); - /* Keep page count to indicate a given hugepage is isolated. */ - list_move(&hpage->lru, &pagelist); + ret = isolate_huge_page(hpage, &pagelist); + if (ret) { + /* + * get_any_page() and isolate_huge_page() takes a refcount each, + * so need to drop one here. + */ + put_page(hpage); + } else { + pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn); + return -EBUSY; + } + ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL, MIGRATE_SYNC, MR_MEMORY_FAILURE); if (ret) {