In slub_order(), the order starts from max(min_order,
get_order(min_objects * size)).  When (min_objects * size) has different
order from (min_objects * size + reserved), it will skip this order via a
check in the loop.

This patch optimizes this a little by calculating the start order with
`reserved' in consideration and removing the check in loop.
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>