Link: https://lore.kernel.org/r/CAOUHufY8+O_MwkrPzgfBKSFwLJ1v6LPDox1yGV0tjX4ozjh2Dw@xxxxxxxxxxxxxx/ Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx> --- mm/memcontrol.c | 2 +- mm/vmscan.c | 6 ++++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8086edbdd39b..ac6440daf208 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6289,7 +6289,7 @@ static void mem_cgroup_attach(struct cgroup_taskset *tset) return; task_lock(task); - if (task->mm && task->mm->owner == task) + if (task->mm && READ_ONCE(task->mm->owner) == task) lru_gen_migrate_mm(task->mm); task_unlock(task); } diff --git a/mm/vmscan.c b/mm/vmscan.c index 629518813b59..8291808ec535 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3270,15 +3270,17 @@ void lru_gen_del_mm(struct mm_struct *mm) void lru_gen_migrate_mm(struct mm_struct *mm) { struct mem_cgroup *memcg; + struct task_struct *task = rcu_dereference_protected(mm->owner, true); - lockdep_assert_held(&mm->owner->alloc_lock); + VM_WARN_ON_ONCE(task->mm != mm); + lockdep_assert_held(&task->alloc_lock); /* for mm_update_next_owner() */ if (mem_cgroup_disabled()) return; rcu_read_lock(); - memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); + memcg = mem_cgroup_from_task(task); rcu_read_unlock(); if (memcg == mm->lru_gen.memcg) return; -- 2.37.3.968.ga6b4b080e4-goog
