1 files changed, 100 insertions, 21 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 011aba6cad70..2011f15278fd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -70,6 +70,7 @@ enum mem_cgroup_stat_index {
         MEM_CGROUP_STAT_PGPGIN_COUNT,   /* # of pages paged in */
         MEM_CGROUP_STAT_PGPGOUT_COUNT,  /* # of pages paged out */
         MEM_CGROUP_STAT_EVENTS, /* sum of pagein + pageout for internal use */
+        MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
 
         MEM_CGROUP_STAT_NSTATS,
 };
@@ -478,11 +479,24 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
         return mz;
 }
 
+static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
+                                         bool charge)
+{
+        int val = (charge) ? 1 : -1;
+        struct mem_cgroup_stat *stat = &mem->stat;
+        struct mem_cgroup_stat_cpu *cpustat;
+        int cpu = get_cpu();
+
+        cpustat = &stat->cpustat[cpu];
+        __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val);
+        put_cpu();
+}
+
 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
                                          struct page_cgroup *pc,
                                          bool charge)
 {
-        int val = (charge)? 1 : -1;
+        int val = (charge) ? 1 : -1;
         struct mem_cgroup_stat *stat = &mem->stat;
         struct mem_cgroup_stat_cpu *cpustat;
         int cpu = get_cpu();
@@ -1285,9 +1299,11 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
         VM_BUG_ON(css_is_removed(&mem->css));
 
         while (1) {
-                int ret;
+                int ret = 0;
                 unsigned long flags = 0;
 
+                if (mem_cgroup_is_root(mem))
+                        goto done;
                 ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res,
                                                 &soft_fail_res);
                 if (likely(!ret)) {
@@ -1347,6 +1363,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                 if (mem_cgroup_soft_limit_check(mem_over_soft_limit))
                         mem_cgroup_update_tree(mem_over_soft_limit, page);
         }
+done:
         return 0;
 nomem:
         css_put(&mem->css);
@@ -1419,9 +1436,12 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
         lock_page_cgroup(pc);
         if (unlikely(PageCgroupUsed(pc))) {
                 unlock_page_cgroup(pc);
-                res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
-                if (do_swap_account)
-                        res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
+                if (!mem_cgroup_is_root(mem)) {
+                        res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
+                        if (do_swap_account)
+                                res_counter_uncharge(&mem->memsw, PAGE_SIZE,
+                                                        NULL);
+                }
                 css_put(&mem->css);
                 return;
         }
@@ -1498,7 +1518,8 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
         if (pc->mem_cgroup != from)
                 goto out;
 
-        res_counter_uncharge(&from->res, PAGE_SIZE, NULL);
+        if (!mem_cgroup_is_root(from))
+                res_counter_uncharge(&from->res, PAGE_SIZE, NULL);
         mem_cgroup_charge_statistics(from, pc, false);
 
         page = pc->page;
@@ -1517,7 +1538,7 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
                                                 1);
         }
 
-        if (do_swap_account)
+        if (do_swap_account && !mem_cgroup_is_root(from))
                 res_counter_uncharge(&from->memsw, PAGE_SIZE, NULL);
         css_put(&from->css);
 
@@ -1588,9 +1609,11 @@ uncharge:
         /* drop extra refcnt by try_charge() */
         css_put(&parent->css);
         /* uncharge if move fails */
-        res_counter_uncharge(&parent->res, PAGE_SIZE, NULL);
-        if (do_swap_account)
-                res_counter_uncharge(&parent->memsw, PAGE_SIZE, NULL);
+        if (!mem_cgroup_is_root(parent)) {
+                res_counter_uncharge(&parent->res, PAGE_SIZE, NULL);
+                if (do_swap_account)
+                        res_counter_uncharge(&parent->memsw, PAGE_SIZE, NULL);
+        }
         return ret;
 }
 
@@ -1779,7 +1802,10 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
                          * This recorded memcg can be obsolete one. So, avoid
                          * calling css_tryget
                          */
-                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE, NULL);
+                        if (!mem_cgroup_is_root(memcg))
+                                res_counter_uncharge(&memcg->memsw, PAGE_SIZE,
+                                                        NULL);
+                        mem_cgroup_swap_statistics(memcg, false);
                         mem_cgroup_put(memcg);
                 }
                 rcu_read_unlock();
@@ -1804,9 +1830,11 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
                 return;
         if (!mem)
                 return;
-        res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
-        if (do_swap_account)
-                res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
+        if (!mem_cgroup_is_root(mem)) {
+                res_counter_uncharge(&mem->res, PAGE_SIZE, NULL);
+                if (do_swap_account)
+                        res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
+        }
         css_put(&mem->css);
 }
 
@@ -1859,9 +1887,14 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
                 break;
         }
 
-        res_counter_uncharge(&mem->res, PAGE_SIZE, &soft_limit_excess);
-        if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
-                res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
+        if (!mem_cgroup_is_root(mem)) {
+                res_counter_uncharge(&mem->res, PAGE_SIZE, &soft_limit_excess);
+                if (do_swap_account &&
+                                (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
+                        res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL);
+        }
+        if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
+                mem_cgroup_swap_statistics(mem, true);
         mem_cgroup_charge_statistics(mem, pc, false);
 
         ClearPageCgroupUsed(pc);
@@ -1952,7 +1985,9 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent)
                  * We uncharge this because swap is freed.
                  * This memcg can be obsolete one. We avoid calling css_tryget
                  */
-                res_counter_uncharge(&memcg->memsw, PAGE_SIZE, NULL);
+                if (!mem_cgroup_is_root(memcg))
+                        res_counter_uncharge(&memcg->memsw, PAGE_SIZE, NULL);
+                mem_cgroup_swap_statistics(memcg, false);
                 mem_cgroup_put(memcg);
         }
         rcu_read_unlock();
@@ -2464,20 +2499,64 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
         return retval;
 }
 
+struct mem_cgroup_idx_data {
+        s64 val;
+        enum mem_cgroup_stat_index idx;
+};
+
+static int
+mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data)
+{
+        struct mem_cgroup_idx_data *d = data;
+        d->val += mem_cgroup_read_stat(&mem->stat, d->idx);
+        return 0;
+}
+
+static void
+mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem,
+                                enum mem_cgroup_stat_index idx, s64 *val)
+{
+        struct mem_cgroup_idx_data d;
+        d.idx = idx;
+        d.val = 0;
+        mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat);
+        *val = d.val;
+}
+
 static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
 {
         struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
-        u64 val = 0;
+        u64 idx_val, val;
         int type, name;
 
         type = MEMFILE_TYPE(cft->private);
         name = MEMFILE_ATTR(cft->private);
         switch (type) {
         case _MEM:
-                val = res_counter_read_u64(&mem->res, name);
+                if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_CACHE, &idx_val);
+                        val = idx_val;
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_RSS, &idx_val);
+                        val += idx_val;
+                        val <<= PAGE_SHIFT;
+                } else
+                        val = res_counter_read_u64(&mem->res, name);
                 break;
         case _MEMSWAP:
-                val = res_counter_read_u64(&mem->memsw, name);
+                if (name == RES_USAGE && mem_cgroup_is_root(mem)) {
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_CACHE, &idx_val);
+                        val = idx_val;
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_RSS, &idx_val);
+                        val += idx_val;
+                        mem_cgroup_get_recursive_idx_stat(mem,
+                                MEM_CGROUP_STAT_SWAPOUT, &idx_val);
+                        val <<= PAGE_SHIFT;
+                } else
+                        val = res_counter_read_u64(&mem->memsw, name);
                 break;
         default:
                 BUG();