[Devel] [PATCH 23/23] slub: create slabinfo file for memcg

[Glauber Costa]

This patch implements mem_cgroup_slabinfo() for the slub.
With that, we can also probe the used caches for it.

Signed-off-by: Glauber Costa <glommer at parallels.com>
CC: Christoph Lameter <cl at linux.com>
CC: Pekka Enberg <penberg at cs.helsinki.fi>
CC: Michal Hocko <mhocko at suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
CC: Johannes Weiner <hannes at cmpxchg.org>
CC: Suleiman Souhlal <suleiman at google.com>
---
 mm/slub.c |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 1031d4d..495a4f1 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4150,6 +4150,33 @@ void kmem_cache_drop_ref(struct kmem_cache *s)
 
 int mem_cgroup_slabinfo(struct mem_cgroup *memcg, struct seq_file *m)
 {
+	struct kmem_cache *s;
+	int node;
+	unsigned long nr_objs = 0;
+	unsigned long nr_free = 0;
+
+	seq_printf(m, "# name            <active_objs> <num_objs> <objsize>\n");
+
+	down_read(&slub_lock);
+	list_for_each_entry(s, &slab_caches, list) {
+		if (s->memcg_params.memcg != memcg)
+			continue;
+
+		for_each_online_node(node) {
+			struct kmem_cache_node *n = get_node(s, node);
+
+			if (!n)
+				continue;
+
+			nr_objs += atomic_long_read(&n->total_objects);
+			nr_free += count_partial(n, count_free);
+		}
+
+		seq_printf(m, "%-17s %6lu %6lu %6u\n", s->name,
+			   nr_objs - nr_free, nr_objs, s->size);
+	}
+	up_read(&slub_lock);
+
 	return 0;
 }
 #endif
-- 
1.7.7.6