diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9f331402e502..33c8dad6830f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4828,7 +4828,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, { struct mem_cgroup *memcg = mem_cgroup_from_css(css); struct mem_cgroup *from; - struct task_struct *p; + struct task_struct *leader, *p; struct mm_struct *mm; unsigned long move_flags; int ret = 0; @@ -4842,7 +4842,20 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, if (!move_flags) return 0; - p = cgroup_taskset_first(tset); + /* + * Multi-process migrations only happen on the default hierarchy + * where charge immigration is not used. Perform charge + * immigration if @tset contains a leader and whine if there are + * multiple. + */ + p = NULL; + cgroup_taskset_for_each_leader(leader, tset) { + WARN_ON_ONCE(p); + p = leader; + } + if (!p) + return 0; + from = mem_cgroup_from_task(p); VM_BUG_ON(from == memcg); |