mm: remove CONFIG_UNEVICTABLE_LRU config option

Currently, nobody wants to turn UNEVICTABLE_LRU off.  Thus this
configurability is unnecessary.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.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 62214c7..d6792f8 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -95,9 +95,7 @@
 	PG_reclaim,		/* To be reclaimed asap */
 	PG_buddy,		/* Page is free, on buddy lists */
 	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
@@ -248,14 +246,8 @@
 	SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache)
 #endif
 
-#ifdef CONFIG_UNEVICTABLE_LRU
 PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable)
 	TESTCLEARFLAG(Unevictable, unevictable)
-#else
-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
@@ -382,12 +374,6 @@
 
 #endif /* !PAGEFLAGS_EXTENDED */
 
-#ifdef CONFIG_UNEVICTABLE_LRU
-#define __PG_UNEVICTABLE	(1 << PG_unevictable)
-#else
-#define __PG_UNEVICTABLE	0
-#endif
-
 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
 #define __PG_MLOCKED		(1 << PG_mlocked)
 #else
@@ -403,7 +389,7 @@
 	 1 << PG_private | 1 << PG_private_2 | \
 	 1 << PG_buddy	 | 1 << PG_writeback | 1 << PG_reserved | \
 	 1 << PG_slab	 | 1 << PG_swapcache | 1 << PG_active | \
-	 __PG_UNEVICTABLE | __PG_MLOCKED)
+	 1 << PG_unevictable | __PG_MLOCKED)
 
 /*
  * Flags checked when a page is prepped for return by the page allocator.