diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 3b3fdfdd4d78..4c17d96bd3a5 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1563,9 +1563,18 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) struct cpuset *mems_oldcs = effective_nodemask_cpuset(oldcs); mpol_rebind_mm(mm, &cpuset_attach_nodemask_to); - if (is_memory_migrate(cs)) - cpuset_migrate_mm(mm, &mems_oldcs->mems_allowed, + + /* + * old_mems_allowed is the same with mems_allowed here, except + * if this task is being moved automatically due to hotplug. + * In that case @mems_allowed has been updated and is empty, + * so @old_mems_allowed is the right nodesets that we migrate + * mm from. + */ + if (is_memory_migrate(cs)) { + cpuset_migrate_mm(mm, &mems_oldcs->old_mems_allowed, &cpuset_attach_nodemask_to); + } mmput(mm); } @@ -2152,10 +2161,12 @@ retry: /* * If sane_behavior flag is set, we need to update tasks' cpumask - * for empty cpuset to take on ancestor's cpumask. + * for empty cpuset to take on ancestor's cpumask. Otherwise, don't + * call update_tasks_cpumask() if the cpuset becomes empty, as + * the tasks in it will be migrated to an ancestor. */ if ((sane && cpumask_empty(cs->cpus_allowed)) || - !cpumask_empty(&off_cpus)) + (!cpumask_empty(&off_cpus) && !cpumask_empty(cs->cpus_allowed))) update_tasks_cpumask(cs, NULL); mutex_lock(&callback_mutex); @@ -2164,10 +2175,12 @@ retry: /* * If sane_behavior flag is set, we need to update tasks' nodemask - * for empty cpuset to take on ancestor's nodemask. + * for empty cpuset to take on ancestor's nodemask. Otherwise, don't + * call update_tasks_nodemask() if the cpuset becomes empty, as + * the tasks in it will be migratd to an ancestor. */ if ((sane && nodes_empty(cs->mems_allowed)) || - !nodes_empty(off_mems)) + (!nodes_empty(off_mems) && !nodes_empty(cs->mems_allowed))) update_tasks_nodemask(cs, NULL); is_empty = cpumask_empty(cs->cpus_allowed) ||