mm: memcontrol: don't pass a NULL memcg to mem_cgroup_end_move()

mem_cgroup_end_move() checks if the passed memcg is NULL, along with a
lengthy comment to explain why this seemingly non-sensical situation is
even possible.

Check in cancel_attach() itself whether can_attach() set up the move
context or not, it's a lot more obvious from there.  Then remove the check
and comment in mem_cgroup_end_move().

Signed-off-by: Johannes Weiner <[email protected]>
Acked-by: Vladimir Davydov <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions