From: Muchun Song songmuchun@bytedance.com

mainline inclusion from mainline-v5.18-rc1 commit be740503ed03ea04ca362330baf082e6a38fe462 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7NXZ6?from=project-issue

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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The idr_alloc() does not include @max ID. So in the current implementation, the maximum memcg ID is 65534 instead of 65535. It seems a bug. So fix this.

Link: https://lkml.kernel.org/r/20220228122126.37293-15-songmuchun@bytedance.com Signed-off-by: Muchun Song songmuchun@bytedance.com Cc: Alex Shi alexs@kernel.org Cc: Anna Schumaker Anna.Schumaker@Netapp.com Cc: Chao Yu chao@kernel.org Cc: Dave Chinner david@fromorbit.com Cc: Fam Zheng fam.zheng@bytedance.com Cc: Jaegeuk Kim jaegeuk@kernel.org Cc: Johannes Weiner hannes@cmpxchg.org Cc: Kari Argillander kari.argillander@gmail.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Michal Hocko mhocko@kernel.org Cc: Qi Zheng zhengqi.arch@bytedance.com Cc: Roman Gushchin roman.gushchin@linux.dev Cc: Shakeel Butt shakeelb@google.com Cc: Theodore Ts'o tytso@mit.edu Cc: Trond Myklebust trond.myklebust@hammerspace.com Cc: Vladimir Davydov vdavydov.dev@gmail.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Wei Yang richard.weiyang@gmail.com Cc: Xiongchun Duan duanxiongchun@bytedance.com Cc: Yang Shi shy828301@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Lu Jialin lujialin4@huawei.com --- mm/memcontrol.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 635cb8b65b86..65accea3a799 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5763,8 +5763,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void) return ERR_PTR(error);

memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, - 1, MEM_CGROUP_ID_MAX, - GFP_KERNEL); + 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL); if (memcg->id.id < 0) { error = memcg->id.id; goto fail;