mm: numa: ensure anon_vma is locked to prevent parallel THP splits
authorMel Gorman <mgorman@suse.de>
Thu, 19 Dec 2013 01:08:38 +0000 (17:08 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 9 Jan 2014 20:24:23 +0000 (12:24 -0800)
commit4455c567b8a231d6aa8bf077facfa559d2605357
tree3641bff83d0512ff16c0d52161c15baa240c6201
parent0b92137e5f67921fef752f55af7efe35a15d2923
mm: numa: ensure anon_vma is locked to prevent parallel THP splits

commit c3a489cac38d43ea6dc4ac240473b44b46deecf7 upstream.

The anon_vma lock prevents parallel THP splits and any associated
complexity that arises when handling splits during THP migration.  This
patch checks if the lock was successfully acquired and bails from THP
migration if it failed for any reason.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/huge_memory.c