From 2f4d7e083ef06582378035df680cc1b4d817ddc7 Mon Sep 17 00:00:00 2001
From: Vladimir Davydov <vdavydov@virtuozzo.com>
Date: Wed, 20 Jan 2016 15:02:38 -0800
Subject: [PATCH] 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>
---
Documentation/kernel-parameters.txt | 1 +
mm/memcontrol.c | 9 +++++++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3ea869d7a31c4..cfb2c0f1a4a89 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -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" }
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9e7a4e5219170..2239e6dd4d4c1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -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;
}
--
2.39.5