per-zone and reclaim enhancements for memory controller: nid/zid helper function for cgroup

Add macro to get node_id and zone_id of page_cgroup.  Will be used in
per-zone-xxx patches and others.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 14cb6142ec4c..422f779a5b21 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -135,6 +135,16 @@ struct page_cgroup {
 #define PAGE_CGROUP_FLAG_CACHE  (0x1)   /* charged as cache */
 #define PAGE_CGROUP_FLAG_ACTIVE (0x2)   /* page is active in this cgroup */
 
+static inline int page_cgroup_nid(struct page_cgroup *pc)
+{
+        return page_to_nid(pc->page);
+}
+
+static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
+{
+        return page_zonenum(pc->page);
+}
+
 enum {
         MEM_CGROUP_TYPE_UNSPEC = 0,
         MEM_CGROUP_TYPE_MAPPED,