From 33925b25d2c00a29664f1994ab350a9bff70f7a2 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 31 Mar 2009 15:23:26 -0700 Subject: [PATCH] nommu: there is no mlock() for NOMMU, so don't provide the bits The mlock() facility does not exist for NOMMU since all mappings are effectively locked anyway, so we don't make the bits available when they're not useful. Signed-off-by: David Howells Reviewed-by: KOSAKI Motohiro Cc: Peter Zijlstra Cc: Greg Ungerer Cc: Johannes Weiner Cc: Rik van Riel Cc: Lee Schermerhorn Cc: Enrik Berkhan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page-flags.h | 28 +++++++++++++++++----------- mm/Kconfig | 8 ++++++++ mm/internal.h | 8 +++++--- 3 files changed, 30 insertions(+), 14 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 219a523ecdb0..61df1779b2a5 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -96,6 +96,8 @@ enum pageflags { PG_swapbacked, /* Page is backed by RAM/swap */ #ifdef CONFIG_UNEVICTABLE_LRU PG_unevictable, /* Page is "unevictable" */ +#endif +#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT PG_mlocked, /* Page is vma mlocked */ #endif #ifdef CONFIG_IA64_UNCACHED_ALLOCATOR @@ -234,22 +236,22 @@ PAGEFLAG_FALSE(SwapCache) #ifdef CONFIG_UNEVICTABLE_LRU PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable) TESTCLEARFLAG(Unevictable, unevictable) - -#define MLOCK_PAGES 1 -PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked) - TESTSCFLAG(Mlocked, mlocked) - #else - -#define MLOCK_PAGES 0 -PAGEFLAG_FALSE(Mlocked) - SETPAGEFLAG_NOOP(Mlocked) TESTCLEARFLAG_FALSE(Mlocked) - PAGEFLAG_FALSE(Unevictable) TESTCLEARFLAG_FALSE(Unevictable) SETPAGEFLAG_NOOP(Unevictable) CLEARPAGEFLAG_NOOP(Unevictable) __CLEARPAGEFLAG_NOOP(Unevictable) #endif +#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT +#define MLOCK_PAGES 1 +PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked) + TESTSCFLAG(Mlocked, mlocked) +#else +#define MLOCK_PAGES 0 +PAGEFLAG_FALSE(Mlocked) + SETPAGEFLAG_NOOP(Mlocked) TESTCLEARFLAG_FALSE(Mlocked) +#endif + #ifdef CONFIG_IA64_UNCACHED_ALLOCATOR PAGEFLAG(Uncached, uncached) #else @@ -367,9 +369,13 @@ static inline void __ClearPageTail(struct page *page) #ifdef CONFIG_UNEVICTABLE_LRU #define __PG_UNEVICTABLE (1 << PG_unevictable) -#define __PG_MLOCKED (1 << PG_mlocked) #else #define __PG_UNEVICTABLE 0 +#endif + +#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT +#define __PG_MLOCKED (1 << PG_mlocked) +#else #define __PG_MLOCKED 0 #endif diff --git a/mm/Kconfig b/mm/Kconfig index a5b77811fdf2..8c895973dfba 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -214,5 +214,13 @@ config UNEVICTABLE_LRU will use one page flag and increase the code size a little, say Y unless you know what you are doing. +config HAVE_MLOCK + bool + default y if MMU=y + +config HAVE_MLOCKED_PAGE_BIT + bool + default y if HAVE_MLOCK=y && UNEVICTABLE_LRU=y + config MMU_NOTIFIER bool diff --git a/mm/internal.h b/mm/internal.h index 478223b73a2a..987bb03fbdd8 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -63,6 +63,7 @@ static inline unsigned long page_order(struct page *page) return page_private(page); } +#ifdef CONFIG_HAVE_MLOCK extern long mlock_vma_pages_range(struct vm_area_struct *vma, unsigned long start, unsigned long end); extern void munlock_vma_pages_range(struct vm_area_struct *vma, @@ -71,6 +72,7 @@ static inline void munlock_vma_pages_all(struct vm_area_struct *vma) { munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); } +#endif #ifdef CONFIG_UNEVICTABLE_LRU /* @@ -90,7 +92,7 @@ static inline void unevictable_migrate_page(struct page *new, struct page *old) } #endif -#ifdef CONFIG_UNEVICTABLE_LRU +#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT /* * Called only in fault path via page_evictable() for a new page * to determine if it's being mapped into a LOCKED vma. @@ -165,7 +167,7 @@ static inline void free_page_mlock(struct page *page) } } -#else /* CONFIG_UNEVICTABLE_LRU */ +#else /* CONFIG_HAVE_MLOCKED_PAGE_BIT */ static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p) { return 0; @@ -175,7 +177,7 @@ static inline void mlock_vma_page(struct page *page) { } static inline void mlock_migrate_page(struct page *new, struct page *old) { } static inline void free_page_mlock(struct page *page) { } -#endif /* CONFIG_UNEVICTABLE_LRU */ +#endif /* CONFIG_HAVE_MLOCKED_PAGE_BIT */ /* * Return the mem_map entry representing the 'offset' subpage within