mm: change isolate mode from #define to bitwise type

Change ISOLATE_XXX macro with bitwise isolate_mode_t type.  Normally,
macro isn't recommended as it's type-unsafe and making debugging harder as
symbol cannot be passed throught to the debugger.

Quote from Johannes
" Hmm, it would probably be cleaner to fully convert the isolation mode
into independent flags.  INACTIVE, ACTIVE, BOTH is currently a
tri-state among flags, which is a bit ugly."

This patch moves isolate mode from swap.h to mmzone.h by memcontrol.h

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 11 insertions, 7 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 343bd7661f2..ac797fa03ef 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -35,7 +35,8 @@ enum mem_cgroup_page_stat_item {
 extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct list_head *dst,
                                         unsigned long *scanned, int order,
-                                        int mode, struct zone *z,
+                                        isolate_mode_t mode,
+                                        struct zone *z,
                                         struct mem_cgroup *mem_cont,
                                         int active, int file);
 
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index be1ac8d7789..436ce6e7a44 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -164,6 +164,14 @@ static inline int is_unevictable_lru(enum lru_list l)
 #define LRU_ALL_EVICTABLE (LRU_ALL_FILE | LRU_ALL_ANON)
 #define LRU_ALL      ((1 << NR_LRU_LISTS) - 1)
 
+/* Isolate inactive pages */
+#define ISOLATE_INACTIVE        ((__force isolate_mode_t)0x1)
+/* Isolate active pages */
+#define ISOLATE_ACTIVE          ((__force isolate_mode_t)0x2)
+
+/* LRU Isolation modes. */
+typedef unsigned __bitwise__ isolate_mode_t;
+
 enum zone_watermarks {
         WMARK_MIN,
         WMARK_LOW,
diff --git a/include/linux/swap.h b/include/linux/swap.h
index c71f84bb62e..1e22e126d2a 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -243,15 +243,10 @@ static inline void lru_cache_add_file(struct page *page)
         __lru_cache_add(page, LRU_INACTIVE_FILE);
 }
 
-/* LRU Isolation modes. */
-#define ISOLATE_INACTIVE 0      /* Isolate inactive pages. */
-#define ISOLATE_ACTIVE 1        /* Isolate active pages. */
-#define ISOLATE_BOTH 2          /* Isolate both active and inactive pages. */
-
 /* linux/mm/vmscan.c */
 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
                                         gfp_t gfp_mask, nodemask_t *mask);
-extern int __isolate_lru_page(struct page *page, int mode, int file);
+extern int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file);
 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
                                                   gfp_t gfp_mask, bool noswap);
 extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,