This ensures that reserved pages are not migrated.  Reserved pages
currently cause the WARN_ON to trigger in migrate_page_add()
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>