[PATCH mm v2 9/9] memcg: enable accounting for percpu allocation of struct rt_rq

Vasily Averin
2022-05-21T16:39:03Z

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
contianers.

Signed-off-by: Vasily Averin <vvs-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
---
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 a32c46889af8..2639d6dcebe6 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -206,7 +206,7 @@ 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