mm: introduce zone_reclaim struct

Add zone_reclam_stat struct for later enhancement.

A later patch uses this.  This patch doesn't any behavior change (yet).

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 10 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 35a7b5e19465..09c14e213b63 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -263,6 +263,19 @@ enum zone_type {
 #error ZONES_SHIFT -- too many zones configured adjust calculation
 #endif
 
+struct zone_reclaim_stat {
+        /*
+         * The pageout code in vmscan.c keeps track of how many of the
+         * mem/swap backed and file backed pages are refeferenced.
+         * The higher the rotated/scanned ratio, the more valuable
+         * that cache is.
+         *
+         * The anon LRU stats live in [0], file LRU stats in [1]
+         */
+        unsigned long           recent_rotated[2];
+        unsigned long           recent_scanned[2];
+};
+
 struct zone {
         /* Fields commonly accessed by the page allocator */
         unsigned long           pages_min, pages_low, pages_high;
@@ -315,16 +328,7 @@ struct zone {
                 unsigned long nr_scan;
         } lru[NR_LRU_LISTS];
 
-        /*
-         * The pageout code in vmscan.c keeps track of how many of the
-         * mem/swap backed and file backed pages are refeferenced.
-         * The higher the rotated/scanned ratio, the more valuable
-         * that cache is.
-         *
-         * The anon LRU stats live in [0], file LRU stats in [1]
-         */
-        unsigned long           recent_rotated[2];
-        unsigned long           recent_scanned[2];
+        struct zone_reclaim_stat reclaim_stat;
 
         unsigned long           pages_scanned;     /* since last reclaim */
         unsigned long           flags;             /* zone flags, see below */