mm: memcg/percpu: per-memcg percpu memory statistics
Percpu memory can represent a noticeable chunk of the total memory
consumption, especially on big machines with many CPUs. Let's track
percpu memory usage for each memcg and display it in memory.stat.
A percpu allocation is usually scattered over multiple pages (and nodes),
and can be significantly smaller than a page. So let's add a byte-sized
counter on the memcg level: MEMCG_PERCPU_B. Byte-sized vmstat infra
created for slabs can be perfectly reused for percpu case.
[guro@fb.com: v3]
Link: http://lkml.kernel.org/r/20200623184515.4132564-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Bixuan Cui <cuibixuan@huawei.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200608230819.832349-4-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/percpu.c b/mm/percpu.c
index dc1a213..f470962 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1610,6 +1610,11 @@ static void pcpu_memcg_post_alloc_hook(struct obj_cgroup *objcg,
if (chunk) {
chunk->obj_cgroups[off >> PCPU_MIN_ALLOC_SHIFT] = objcg;
+
+ rcu_read_lock();
+ mod_memcg_state(obj_cgroup_memcg(objcg), MEMCG_PERCPU_B,
+ size * num_possible_cpus());
+ rcu_read_unlock();
} else {
obj_cgroup_uncharge(objcg, size * num_possible_cpus());
obj_cgroup_put(objcg);
@@ -1628,6 +1633,11 @@ static void pcpu_memcg_free_hook(struct pcpu_chunk *chunk, int off, size_t size)
obj_cgroup_uncharge(objcg, size * num_possible_cpus());
+ rcu_read_lock();
+ mod_memcg_state(obj_cgroup_memcg(objcg), MEMCG_PERCPU_B,
+ -(size * num_possible_cpus()));
+ rcu_read_unlock();
+
obj_cgroup_put(objcg);
}