[PATCH v2 1/3] mm, memcg: mark cgroup_memory_nosocket, nokmem and noswap as __ro_after_init

From: Roman Gushchin
Date: Wed Jun 02 2021 - 21:09:50 EST


cgroup_memory_nosocket, cgroup_memory_nokmem and cgroup_memory_noswap
are initialized during the kernel initialization and never change
their value afterwards.

cgroup_memory_nosocket, cgroup_memory_nokmem are written only from
cgroup_memory(), which is marked as __init.

cgroup_memory_noswap is written from setup_swap_account() and
mem_cgroup_swap_init(), both are marked as __init.

Mark all three variables as __ro_after_init.

Signed-off-by: Roman Gushchin <guro@xxxxxx>
---
mm/memcontrol.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e064ac0d850a..e6203ee24a11 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -80,14 +80,14 @@ struct mem_cgroup *root_mem_cgroup __read_mostly;
DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg);

/* Socket memory accounting disabled? */
-static bool cgroup_memory_nosocket;
+static bool cgroup_memory_nosocket __ro_after_init;

/* Kernel memory accounting disabled? */
-static bool cgroup_memory_nokmem;
+static bool cgroup_memory_nokmem __ro_after_init;

/* Whether the swap controller is active */
#ifdef CONFIG_MEMCG_SWAP
-bool cgroup_memory_noswap __read_mostly;
+bool cgroup_memory_noswap __ro_after_init;
#else
#define cgroup_memory_noswap 1
#endif
--
2.31.1