mm: memcontrol: allow to disable kmem accounting for cgroup2

Kmem accounting might incur overhead that some users can't put up with.
Besides, the implementation is still considered unstable.  So let's
provide a way to disable it for those users who aren't happy with it.

To disable kmem accounting for cgroup2, pass cgroup.memory=nokmem at
boot time.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vladimir Davydov 2016-01-20 15:02:38 -08:00 committed by Linus Torvalds
parent 52c29b0482
commit 04823c833b
2 changed files with 8 additions and 2 deletions

View File

@ -611,6 +611,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
cgroup.memory= [KNL] Pass options to the cgroup memory controller.
Format: <string>
nosocket -- Disable socket memory accounting.
nokmem -- Disable kernel memory accounting.
checkreqprot [SELINUX] Set initial checkreqprot flag value.
Format: { "0" | "1" }

View File

@ -83,6 +83,9 @@ struct mem_cgroup *root_mem_cgroup __read_mostly;
/* Socket memory accounting disabled? */
static bool cgroup_memory_nosocket;
/* Kernel memory accounting disabled? */
static bool cgroup_memory_nokmem;
/* Whether the swap controller is active */
#ifdef CONFIG_MEMCG_SWAP
int do_swap_account __read_mostly;
@ -2925,8 +2928,8 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
* onlined after this point, because it has at least one child
* already.
*/
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) ||
memcg_kmem_online(parent))
if (memcg_kmem_online(parent) ||
(cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nokmem))
ret = memcg_online_kmem(memcg);
mutex_unlock(&memcg_limit_mutex);
return ret;
@ -5638,6 +5641,8 @@ static int __init cgroup_memory(char *s)
continue;
if (!strcmp(token, "nosocket"))
cgroup_memory_nosocket = true;
if (!strcmp(token, "nokmem"))
cgroup_memory_nokmem = true;
}
return 0;
}