cpusets-stall-when-updating-mems_allowed-for-mempolicy-or-disjoint-nodemask-fix-2

cpusets-stall-when-updating-mems_allowed-for-mempolicy-or-disjoint-nodemask-fix-2

Here's a cleaner way of doing it, we can extend it to mm/slab.c later.
Please fold into
cpusets-stall-when-updating-mems_allowed-for-mempolicy-or-disjoint-nodemask.patch.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>