mm: memcontrol: add "sock" to cgroup2 memory.stat

Provide statistics on how much of a cgroup's memory footprint is made up
of socket buffers from network connections owned by the group.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 10 insertions, 1 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 166661708410..9ae48d4aeb5e 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -50,6 +50,9 @@ enum mem_cgroup_stat_index {
         MEM_CGROUP_STAT_WRITEBACK,      /* # of pages under writeback */
         MEM_CGROUP_STAT_SWAP,           /* # of pages, swapped out */
         MEM_CGROUP_STAT_NSTATS,
+        /* default hierarchy stats */
+        MEMCG_SOCK,
+        MEMCG_NR_STAT,
 };
 
 struct mem_cgroup_reclaim_cookie {
@@ -87,7 +90,7 @@ enum mem_cgroup_events_target {
 
 #ifdef CONFIG_MEMCG
 struct mem_cgroup_stat_cpu {
-        long count[MEM_CGROUP_STAT_NSTATS];
+        long count[MEMCG_NR_STAT];
         unsigned long events[MEMCG_NR_EVENTS];
         unsigned long nr_page_events;
         unsigned long targets[MEM_CGROUP_NTARGETS];
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 98f4109bff6c..ca052f2a4a0b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5128,6 +5128,8 @@ static int memory_stat_show(struct seq_file *m, void *v)
                    (u64)tree_stat(memcg, MEM_CGROUP_STAT_RSS) * PAGE_SIZE);
         seq_printf(m, "file %llu\n",
                    (u64)tree_stat(memcg, MEM_CGROUP_STAT_CACHE) * PAGE_SIZE);
+        seq_printf(m, "sock %llu\n",
+                   (u64)tree_stat(memcg, MEMCG_SOCK) * PAGE_SIZE);
 
         seq_printf(m, "file_mapped %llu\n",
                    (u64)tree_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED) *
@@ -5631,6 +5633,8 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
         if (in_softirq())
                 gfp_mask = GFP_NOWAIT;
 
+        this_cpu_add(memcg->stat->count[MEMCG_SOCK], nr_pages);
+
         if (try_charge(memcg, gfp_mask, nr_pages) == 0)
                 return true;
 
@@ -5650,6 +5654,8 @@ void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
                 return;
         }
 
+        this_cpu_sub(memcg->stat->count[MEMCG_SOCK], nr_pages);
+
         page_counter_uncharge(&memcg->memory, nr_pages);
         css_put_many(&memcg->css, nr_pages);
 }