[PATCH] mm/page_poison: move PAGE_POISON to page_poison.c

[Wei Wang]

The PAGE_POISON macro is used in page_poison.c only, so avoid exporting
it. Also remove the "mm/debug-pagealloc.c" related comment, which is
obsolete.

Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
 include/linux/poison.h | 7 -------
 mm/page_poison.c       | 6 ++++++
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/include/linux/poison.h b/include/linux/poison.h
index 15927eb..348bf67 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -30,13 +30,6 @@
  */
 #define TIMER_ENTRY_STATIC	((void *) 0x300 + POISON_POINTER_DELTA)
 
-/********** mm/debug-pagealloc.c **********/
-#ifdef CONFIG_PAGE_POISONING_ZERO
-#define PAGE_POISON 0x00
-#else
-#define PAGE_POISON 0xaa
-#endif
-
 /********** mm/page_alloc.c ************/
 
 #define TAIL_MAPPING	((void *) 0x400 + POISON_POINTER_DELTA)
diff --git a/mm/page_poison.c b/mm/page_poison.c
index e83fd44..8aaf076 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -7,6 +7,12 @@
 #include <linux/poison.h>
 #include <linux/ratelimit.h>
 
+#ifdef CONFIG_PAGE_POISONING_ZERO
+#define PAGE_POISON 0x00
+#else
+#define PAGE_POISON 0xaa
+#endif
+
 static bool want_page_poisoning __read_mostly;
 
 static int early_page_poison_param(char *buf)
-- 
2.7.4