From 60b1e24ce8c3334d9204d6229356b750632136be Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@huawei.com>
Date: Sat, 8 Jul 2023 10:33:04 +0800
Subject: mm/memcg: minor cleanup for MEM_CGROUP_ID_MAX

MEM_CGROUP_ID_MAX is only used when CONFIG_MEMCG is configured.  So remove
unneeded !CONFIG_MEMCG variant.  Also it's only used in
mem_cgroup_alloc(), so move it from memcontrol.h to memcontrol.c.  And
further define it as:

  #define MEM_CGROUP_ID_MAX ((1UL << MEM_CGROUP_ID_SHIFT) - 1)

so if someone changes MEM_CGROUP_ID_SHIFT in the future, then
MEM_CGROUP_ID_MAX will be updated accordingly, as suggested by Muchun.

Link: https://lkml.kernel.org/r/20230708023304.1184111-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/memcontrol.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'mm/memcontrol.c')

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ab99503c9ff2..3eaeb69ef9f5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5155,6 +5155,7 @@ static struct cftype mem_cgroup_legacy_files[] = {
  * those references are manageable from userspace.
  */
 
+#define MEM_CGROUP_ID_MAX	((1UL << MEM_CGROUP_ID_SHIFT) - 1)
 static DEFINE_IDR(mem_cgroup_idr);
 
 static void mem_cgroup_id_remove(struct mem_cgroup *memcg)
-- 
cgit