[PATCH mm v5 9/9] memcg: enable accounting for perpu allocation of struct rt_rq

[Vasily Averin <vvs@openvz.org>]

If enabled in config, alloc_rt_sched_group() is called for each new
cpu cgroup and allocates a huge (~1700 bytes) percpu struct rt_rq.
This significantly exceeds the size of the percpu allocation in the
common part of cgroup creation.

Memory allocated during new cpu cgroup creation
(with enabled RT_GROUP_SCHED):
common part:    ~11Kb   +   318 bytes percpu
cpu cgroup:     ~2.5Kb  + ~2800 bytes percpu

Accounting for this memory helps to avoid misuse inside memcg-limited
containers.

Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
---
 kernel/sched/rt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8c9ed9664840..44a8fc096e33 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -256,7 +256,7 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
 
 	for_each_possible_cpu(i) {
 		rt_rq = kzalloc_node(sizeof(struct rt_rq),
-				     GFP_KERNEL, cpu_to_node(i));
+				     GFP_KERNEL_ACCOUNT, cpu_to_node(i));
 		if (!rt_rq)
 			goto err;
 
-- 
2.36.1