Memory controller: make charging gfp mask aware

Nick Piggin pointed out that swap cache and page cache addition routines
could be called from non GFP_KERNEL contexts.  This patch makes the
charging routine aware of the gfp context.  Charging might fail if the
cgroup is over it's limit, in which case a suitable error is returned.

This patch was tested on a Powerpc box.  I am still looking at being able
to test the path, through which allocations happen in non GFP_KERNEL
contexts.

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

1 files changed, 5 insertions, 9 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 215f6a726b2f..b7d868cbca09 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1337,16 +1337,11 @@ unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
 
 #ifdef CONFIG_CGROUP_MEM_CONT
 
-#ifdef CONFIG_HIGHMEM
-#define ZONE_USERPAGES ZONE_HIGHMEM
-#else
-#define ZONE_USERPAGES ZONE_NORMAL
-#endif
-
-unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont)
+unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
+                                                gfp_t gfp_mask)
 {
         struct scan_control sc = {
-                .gfp_mask = GFP_KERNEL,
+                .gfp_mask = gfp_mask,
                 .may_writepage = !laptop_mode,
                 .may_swap = 1,
                 .swap_cluster_max = SWAP_CLUSTER_MAX,
@@ -1357,9 +1352,10 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont)
         };
         int node;
         struct zone **zones;
+        int target_zone = gfp_zone(GFP_HIGHUSER_MOVABLE);
 
         for_each_online_node(node) {
-                zones = NODE_DATA(node)->node_zonelists[ZONE_USERPAGES].zones;
+                zones = NODE_DATA(node)->node_zonelists[target_zone].zones;
                 if (do_try_to_free_pages(zones, sc.gfp_mask, &sc))
                         return 1;
         }