thp: enable direct defrag

With memory compaction in, and lumpy-reclaim disabled, it seems safe
enough to defrag memory during the (synchronous) transparent hugepage page
faults (TRANSPARENT_HUGEPAGE_DEFRAG_FLAG) and not only during khugepaged
(async) hugepage allocations that was already enabled even before memory
compaction was in (TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG).

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c

@@ -28,6 +28,7 @@
  */
 unsigned long transparent_hugepage_flags __read_mostly =
 	(1<<TRANSPARENT_HUGEPAGE_FLAG)|
+	(1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)|
 	(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
 
 /* default scan 8*512 pte (or vmas) every 30 second */