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 <dhowells@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Enrik Berkhan <Enrik.Berkhan@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 219a523..61df177 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -96,6 +96,8 @@
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 @@
#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 @@
#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 a5b7781..8c89597 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -214,5 +214,13 @@
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 478223b..987bb03 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -63,6 +63,7 @@
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 @@
{
munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
}
+#endif
#ifdef CONFIG_UNEVICTABLE_LRU
/*
@@ -90,7 +92,7 @@
}
#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 @@
}
}
-#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_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