Creating each new cgroup allocates 4Kb for struct cgroup. This is the largest memory allocation in this scenario and is epecially important for small VMs with 1-2 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 Accounting of this memory helps to avoid misuse inside memcg-limited containers. Signed-off-by: Vasily Averin <vvs@xxxxxxxxxx> Reviewed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx> Reviewed-by: Michal Koutný <mkoutny@xxxxxxxx> Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> --- kernel/cgroup/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 90a654cb8a1e..9adf4ad4b623 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5353,7 +5353,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, /* allocate the cgroup and its ID, 0 is reserved for the root */ cgrp = kzalloc(struct_size(cgrp, ancestor_ids, (level + 1)), - GFP_KERNEL); + GFP_KERNEL_ACCOUNT); if (!cgrp) return ERR_PTR(-ENOMEM); -- 2.36.1
