diff options
| -rw-r--r-- | fs/hugetlbfs/inode.c | 2 | ||||
| -rw-r--r-- | include/linux/hugetlb.h | 7 | ||||
| -rw-r--r-- | include/linux/page-flags.h | 6 | ||||
| -rw-r--r-- | mm/hugetlb.c | 45 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 9 |
5 files changed, 25 insertions, 44 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 907f6405e805..5a8ed6bd4f87 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -735,7 +735,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, mutex_unlock(&hugetlb_fault_mutex_table[hash]); - set_page_huge_active(page); + SetHPageMigratable(page); /* * unlock_page because locked by add_to_page_cache() * put_page() due to reference from alloc_huge_page() diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 249c65e1d8ca..77f2a032fe32 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -480,9 +480,13 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, * HPG_restore_reserve - Set when a hugetlb page consumes a reservation at * allocation time. Cleared when page is fully instantiated. Free * routine checks flag to restore a reservation on error paths. + * HPG_migratable - Set after a newly allocated page is added to the page + * cache and/or page tables. Indicates the page is a candidate for + * migration. */ enum hugetlb_page_flags { HPG_restore_reserve = 0, + HPG_migratable, __NR_HPAGEFLAGS, }; @@ -525,6 +529,7 @@ static inline void ClearHPage##uname(struct page *page) \ * Create functions associated with hugetlb page flags */ HPAGEFLAG(RestoreReserve, restore_reserve) +HPAGEFLAG(Migratable, migratable) #ifdef CONFIG_HUGETLB_PAGE @@ -838,8 +843,6 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, } #endif -void set_page_huge_active(struct page *page); - #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index ec5d0290e0ee..db914477057b 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -592,15 +592,9 @@ static inline void ClearPageCompound(struct page *page) #ifdef CONFIG_HUGETLB_PAGE int PageHuge(struct page *page); int PageHeadHuge(struct page *page); -bool page_huge_active(struct page *page); #else TESTPAGEFLAG_FALSE(Huge) TESTPAGEFLAG_FALSE(HeadHuge) - -static inline bool page_huge_active(struct page *page) -{ - return 0; -} #endif diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f5e85dabb7a3..727c09713627 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1365,30 +1365,6 @@ struct hstate *size_to_hstate(unsigned long size) } /* - * 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) -{ - return PageHeadHuge(page) && PagePrivate(&page[1]); -} - -/* never called for tail page */ -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]); -} - -/* * Internal hugetlb specific page flag. Do not use outside of the hugetlb * code */ @@ -1449,7 +1425,7 @@ static void __free_huge_page(struct page *page) } spin_lock(&hugetlb_lock); - clear_page_huge_active(page); + ClearHPageMigratable(page); hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h), page); hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), @@ -4218,7 +4194,7 @@ retry_avoidcopy: make_huge_pte(vma, new_page, 1)); page_remove_rmap(old_page, true); hugepage_add_new_anon_rmap(new_page, vma, haddr); - set_page_huge_active(new_page); + SetHPageMigratable(new_page); /* Make the old page be freed below */ new_page = old_page; } @@ -4455,12 +4431,12 @@ retry: spin_unlock(ptl); /* - * Only make newly allocated pages active. Existing pages found - * in the pagecache could be !page_huge_active() if they have been - * isolated for migration. + * Only set HPageMigratable in newly allocated pages. Existing pages + * found in the pagecache may not have HPageMigratableset if they have + * been isolated for migration. */ if (new_page) - set_page_huge_active(page); + SetHPageMigratable(page); unlock_page(page); out: @@ -4771,7 +4747,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, update_mmu_cache(dst_vma, dst_addr, dst_pte); spin_unlock(ptl); - set_page_huge_active(page); + SetHPageMigratable(page); if (vm_shared) unlock_page(page); ret = 0; @@ -5610,12 +5586,13 @@ bool isolate_huge_page(struct page *page, struct list_head *list) bool ret = true; spin_lock(&hugetlb_lock); - if (!PageHeadHuge(page) || !page_huge_active(page) || + if (!PageHeadHuge(page) || + !HPageMigratable(page) || !get_page_unless_zero(page)) { ret = false; goto unlock; } - clear_page_huge_active(page); + ClearHPageMigratable(page); list_move_tail(&page->lru, list); unlock: spin_unlock(&hugetlb_lock); @@ -5625,7 +5602,7 @@ unlock: void putback_active_hugepage(struct page *page) { spin_lock(&hugetlb_lock); - set_page_huge_active(page); + SetHPageMigratable(page); list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); spin_unlock(&hugetlb_lock); put_page(page); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index ddcb1cd24c60..abe43c1ae920 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1260,7 +1260,14 @@ static int scan_movable_pages(unsigned long start, unsigned long end, if (!PageHuge(page)) continue; head = compound_head(page); - if (page_huge_active(head)) + /* + * This test is racy as we hold no reference or lock. The + * hugetlb page could have been free'ed and head is no longer + * a hugetlb page before the following check. In such unlikely + * cases false positives and negatives are possible. Calling + * code must deal with these scenarios. + */ + if (HPageMigratable(head)) goto found; skip = compound_nr(head) - (page - head); pfn += skip - 1; |