[PATCH mm v3 9/9] memcg: enable accounting for perpu allocation of struct rt_rq

Vasily Averin
2022-05-30T11:27:07Z

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-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
Acked-by: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Acked-by: Roman Gushchin <roman.gushchin-fxUVXftIFDnyG1zEObXtfA@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 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