> On Jul 6, 2023, at 19:28, Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote: > > MEM_CGROUP_ID_MAX is only used when CONFIG_MEMCG is configured. Remove > unneeded !CONFIG_MEMCG variant. > > Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> MEM_CGROUP_ID_MAX is also only used in mem_cgroup_alloc(), maybe you also could move it from memcontrol.h to memcontrol.c. And define it as: #define MEM_CGROUP_ID_MAX ((1U << MEM_CGROUP_ID_SHIFT) - 1) I am not suggesting defining it as USHRT_MAX, because if someone changes MEM_CGROUP_ID_SHIFT in the future, then MEM_CGROUP_ID_MAX will not updated accordingly. For this patch, LGTM. Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Thanks.