[PATCH mm v4 5/9] memcg: enable accounting for percpu allocation of struct psi_group_cpu

Vasily Averin
2022-06-13T05:35:17Z

struct pci_group_cpu is percpu allocated for each new cgroup and can
consume a significant portion of all allocated memory on nodes with
a large number of CPUs.

Common part of the cgroup creation:
Allocs Alloc $1*$2 Sum Allocation
number size
--------------------------------------------
16 ~ 352 5632 5632 KERNFS
1 + 4096 4096 9728 (cgroup_mkdir+0xe4)
1 584 584 10312 (radix_tree_node_alloc.constprop.0+0x89)
1 192 192 10504 (__d_alloc+0x29)
2 72 144 10648 (avc_alloc_node+0x27)
2 64 128 10776 (percpu_ref_init+0x6a)
1 64 64 10840 (memcg_list_lru_alloc+0x21a)
percpu:
1 + 192 192 192 call_site=psi_cgroup_alloc+0x1e
1 + 96 96 288 call_site=cgroup_rstat_init+0x5f
2 12 24 312 call_site=percpu_ref_init+0x23
1 6 6 318 call_site=__percpu_counter_init+0x22

'+' -- to be accounted,
'~' -- partially accounted

Signed-off-by: Vasily Averin <vvs-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
Acked-by: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Reviewed-by: Muchun Song <songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>
Acked-by: Roman Gushchin <roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org>
---
kernel/sched/psi.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index ec66b40bdd40..c95e87269fc5 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -957,11 +957,12 @@ int psi_cgroup_alloc(struct cgroup *cgroup)
if (static_branch_likely(&psi_disabled))
return 0;

- cgroup->psi = kmalloc(sizeof(struct psi_group), GFP_KERNEL);
+ cgroup->psi = kmalloc(sizeof(struct psi_group), GFP_KERNEL_ACCOUNT);
if (!cgroup->psi)
return -ENOMEM;

- cgroup->psi->pcpu = alloc_percpu(struct psi_group_cpu);
+ cgroup->psi->pcpu = alloc_percpu_gfp(struct psi_group_cpu,
+ GFP_KERNEL_ACCOUNT);
if (!cgroup->psi->pcpu) {
kfree(cgroup->psi);
return -ENOMEM;
--
2.36.1