4 files changed, 57 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 532eacbbed62..fb849020aea9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1562,6 +1562,9 @@ and is between 256 and 4096 characters. It is defined in the file
 
         nosoftlockup    [KNL] Disable the soft-lockup detector.
 
+        noswapaccount   [KNL] Disable accounting of swap in memory resource
+                        controller. (See Documentation/controllers/memory.txt)
+
         nosync          [HW,M68K] Disables sync negotiation for all devices.
 
         notsc           [BUGS=X86-32] Disable Time Stamp Counter
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b095f5f6ecf7..41b46cc9d1f1 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -77,6 +77,9 @@ extern void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem,
 extern long mem_cgroup_calc_reclaim(struct mem_cgroup *mem, struct zone *zone,
                                         int priority, enum lru_list lru);
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+extern int do_swap_account;
+#endif
 
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 struct mem_cgroup;
diff --git a/init/Kconfig b/init/Kconfig
index 7cbe1f43ca22..a724a149bf3f 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -428,6 +428,23 @@ config CGROUP_MEM_RES_CTLR
 config MM_OWNER
         bool
 
+config CGROUP_MEM_RES_CTLR_SWAP
+        bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
+        depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
+        help
+          Add swap management feature to memory resource controller. When you
+          enable this, you can limit mem+swap usage per cgroup. In other words,
+          when you disable this, memory resource controller has no cares to
+          usage of swap...a process can exhaust all of the swap. This extension
+          is useful when you want to avoid exhaustion swap but this itself
+          adds more overheads and consumes memory for remembering information.
+          Especially if you use 32bit system or small memory system, please
+          be careful about enabling this. When memory resource controller
+          is disabled by boot option, this will be automatically disabled and
+          there will be no overhead from this. Even when you set this config=y,
+          if boot option "noswapaccount" is set, swap will not be accounted.
+
+
 endmenu
 
 config SYSFS_DEPRECATED
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7288e9d85ca7..59dd8c116372 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -41,6 +41,15 @@
 struct cgroup_subsys mem_cgroup_subsys __read_mostly;
 #define MEM_CGROUP_RECLAIM_RETRIES      5
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
+int do_swap_account __read_mostly;
+static int really_do_swap_account __initdata = 1; /* for remember boot option*/
+#else
+#define do_swap_account         (0)
+#endif
+
+
 /*
  * Statistics for memory cgroup.
  */
@@ -1404,6 +1413,18 @@ static void mem_cgroup_free(struct mem_cgroup *mem)
 }
 
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static void __init enable_swap_cgroup(void)
+{
+        if (!mem_cgroup_subsys.disabled && really_do_swap_account)
+                do_swap_account = 1;
+}
+#else
+static void __init enable_swap_cgroup(void)
+{
+}
+#endif
+
 static struct cgroup_subsys_state *
 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 {
@@ -1419,6 +1440,9 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
         for_each_node_state(node, N_POSSIBLE)
                 if (alloc_mem_cgroup_per_zone_info(mem, node))
                         goto free_out;
+        /* root ? */
+        if (cont->parent == NULL)
+                enable_swap_cgroup();
 
         return &mem->css;
 free_out:
@@ -1490,3 +1514,13 @@ struct cgroup_subsys mem_cgroup_subsys = {
         .attach = mem_cgroup_move_task,
         .early_init = 0,
 };
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+
+static int __init disable_swap_account(char *s)
+{
+        really_do_swap_account = 0;
+        return 1;
+}
+__setup("noswapaccount", disable_swap_account);
+#endif