The patch titled Subject: memcg: remove lru_add_drain_all() invocation from mem_cgroup_move_charge() has been removed from the -mm tree. Its filename was memcg-remove-lru_add_drain_all-invocation-from-mem_cgroup_move_charge.patch This patch was dropped because it was withdrawn ------------------------------------------------------ From: Tejun Heo <tj@xxxxxxxxxx> Subject: memcg: remove lru_add_drain_all() invocation from mem_cgroup_move_charge() mem_cgroup_move_charge() invokes lru_add_drain_all() so that the pvec pages can be moved too. lru_add_drain_all() schedules and flushes work items on system_wq which depends on being able to create new kworkers to make forward progress. Since 1ed1328792ff ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"), a new task can't be created while in the cgroup migration path and the described lru_add_drain_all() invocation can easily lead to a deadlock. Charge moving is best-effort and whether the pvec pages are migrated or not doesn't really matter. Don't call it during charge moving. Eventually, we want to move the actual charge moving outside the migration path. Fixes: 1ed1328792ff ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem") Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Debugged-by: Petr Mladek <pmladek@xxxxxxxx> Tested-by: Petr Mladek <pmladek@xxxxxxxx> Reported-by: Cyril Hrubis <chrubis@xxxxxxx> Reported-by: Johannes Weiner <hannes@xxxxxxxxxxx> Suggested-by: Michal Hocko <mhocko@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [4.4+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 1 - 1 file changed, 1 deletion(-) diff -puN mm/memcontrol.c~memcg-remove-lru_add_drain_all-invocation-from-mem_cgroup_move_charge mm/memcontrol.c --- a/mm/memcontrol.c~memcg-remove-lru_add_drain_all-invocation-from-mem_cgroup_move_charge +++ a/mm/memcontrol.c @@ -4859,7 +4859,6 @@ static void mem_cgroup_move_charge(struc .mm = mm, }; - lru_add_drain_all(); /* * Signal lock_page_memcg() to take the memcg's move_lock * while we're moving its pages to another memcg. Then wait _ Patches currently in -mm which might be from tj@xxxxxxxxxx are -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html