mm: compaction: use synchronous compaction for /proc/sys/vm/compact_memory

When asynchronous compaction was introduced, the
/proc/sys/vm/compact_memory handler should have been updated to always use
synchronous compaction.  This did not happen so this patch addresses it.

The assumption is if a user writes to /proc/sys/vm/compact_memory, they
are willing for that process to stall.

Signed-off-by: Mel Gorman <[email protected]>
Reviewed-by: Andrea Arcangeli <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>
Cc: Dave Jones <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Andy Isaacson <[email protected]>
Cc: Nai Xia <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 396ea2b47f7e..d31e64becb38 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -668,6 +668,7 @@ static int compact_node(int nid)
 			.nr_freepages = 0,
 			.nr_migratepages = 0,
 			.order = -1,
+			.sync = true,
 		};
 
 		zone = &pgdat->node_zones[zoneid];