mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled
mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled

There is a seqcounter that protects against spurious allocation failures
when a task is changing the allowed nodes in a cpuset.  There is no need
to check the seqcounter until a cpuset exists.

Signed-off-by: Mel Gorman <39ea6a09710987173e32e37c86918024a0f441c1@techsingularity.net>
Acked-by: Christoph Lameter <ef3ecccf258fa062c5c6521a4887d40541963af7@linux.com>
Acked-by: David Rientjes <d8cd2994e15bc61ddb2b113030bda55eebc3a0fe@google.com>
Acked-by: Vlastimil Babka <db766431e3f0373ca1ec8fa855cfd5f84b2f2eb6@suse.cz>
Acked-by: Michal Hocko <829500b200af6c2a0eca4dfd5c388e6b8fbe8dc6@suse.com>
Acked-by: Johannes Weiner <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@cmpxchg.org>
Cc: Vitaly Wool <b9819a7c4871188f9eb85e41467147383d63ebc9@gmail.com>
Cc: Rik van Riel <a21938f5d463ddf41aa718934c205ca2cce8ebbc@redhat.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs