memory.max_usage.diff

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 36db05f..be54063 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4942,6 +4942,14 @@ static u64 memory_current_read(struct cgroup_subsys_state *css,
        return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE;
 }
 
+static u64 memory_max_usage_read(struct cgroup_subsys_state *css,
+                              struct cftype *cft)
+{
+       struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+       return (u64)memcg->memory.watermark * PAGE_SIZE;
+}
+
 static int memory_low_show(struct seq_file *m, void *v)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
@@ -5155,6 +5163,11 @@ static struct cftype memory_files[] = {
                .read_u64 = memory_current_read,
        },
        {
+               .name = "max_usage",
+               .flags = CFTYPE_NOT_ON_ROOT,
+               .read_u64 = memory_max_usage_read,
+       },
+       {
                .name = "low",
                .flags = CFTYPE_NOT_ON_ROOT,
                .seq_show = memory_low_show,
@@ -5877,6 +5890,14 @@ static u64 swap_current_read(struct cgroup_subsys_state *css,
        return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE;
 }
 
+static u64 swap_max_usage_read(struct cgroup_subsys_state *css,
+                            struct cftype *cft)
+{
+       struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+       return (u64)memcg->swap.watermark * PAGE_SIZE;
+}
+
 static int swap_max_show(struct seq_file *m, void *v)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
@@ -5918,6 +5939,11 @@ static struct cftype swap_files[] = {
                .read_u64 = swap_current_read,
        },
        {
+               .name = "swap.max_usage",
+               .flags = CFTYPE_NOT_ON_ROOT,
+               .read_u64 = swap_max_usage_read,
+       },
+       {
                .name = "swap.max",
                .flags = CFTYPE_NOT_ON_ROOT,
                .seq_show = swap_max_show,