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From:   Roman Gushchin <guro@fb.com>
To:     Dennis Zhou <dennis@kernel.org>
CC:     Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, Roman Gushchin <guro@fb.com>
Subject: [PATCH v2 1/3] mm, memcg: mark cgroup_memory_nosocket, nokmem and noswap as __ro_after_init
Date:   Wed, 2 Jun 2021 18:09:29 -0700
Message-ID: <20210603010931.1472512-2-guro@fb.com>
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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@fb.com>
---
 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);
=20
 /* Socket memory accounting disabled? */
-static bool cgroup_memory_nosocket;
+static bool cgroup_memory_nosocket __ro_after_init;
=20
 /* Kernel memory accounting disabled? */
-static bool cgroup_memory_nokmem;
+static bool cgroup_memory_nokmem __ro_after_init;
=20
 /* 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
--=20
2.31.1