mm: hugetlb: use get_page_foll() in follow_hugetlb_page()
mm: hugetlb: use get_page_foll() in follow_hugetlb_page()

get_page_foll() is more optimal and is always safe to use under the PT
lock.  More so for hugetlbfs as there's no risk of race conditions with
split_huge_page regardless of the PT lock.

Signed-off-by: Andrea Arcangeli <6cb163d975a8c4c46420677e0054b55c39bdb339@redhat.com>
Tested-by: Khalid Aziz <268b168f6e68003afd4dc22fb518c70145f37320@oracle.com>
Cc: Pravin Shelar <95dcc1879f3489c0d5163907cdd946775296b2dd@nicira.com>
Cc: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>
Cc: Ben Hutchings <0672176982fbc629cc374f31a7a45ae1671abf90@solarflare.com>
Cc: Christoph Lameter <ef3ecccf258fa062c5c6521a4887d40541963af7@linux.com>
Cc: Johannes Weiner <5332d5d6802f0c4180a1f65eb38cf05f0ccdfd97@redhat.com>
Cc: Mel Gorman <39ea6a09710987173e32e37c86918024a0f441c1@suse.de>
Cc: Rik van Riel <a21938f5d463ddf41aa718934c205ca2cce8ebbc@redhat.com>
Cc: Andi Kleen <dbd122ef7b6a09ffecf5db9c9296320f3c94e707@firstfloor.org>
Cc: Minchan Kim <eee62f459f15dcddf87a8df69e8328e2a2562028@kernel.org>
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