We do proactive compaction with order == -1 via
1. /proc/sys/vm/compact_memory
2. /sys/devices/system/node/nodex/compact
3. /proc/sys/vm/compaction_proactiveness
Add missed situation in which order == -1.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
---
 mm/compaction.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index c377d78e0f15..ff3426a0d9c5 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2065,8 +2065,10 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc)
 }
 
 /*
- * order == -1 is expected when compacting via
- * /proc/sys/vm/compact_memory
+ * order == -1 is expected when compacting proactively via
+ * 1. /proc/sys/vm/compact_memory
+ * 2. /sys/devices/system/node/nodex/compact
+ * 3. /proc/sys/vm/compaction_proactiveness
  */
 static inline bool is_via_compact_memory(int order)
 {
-- 
2.30.0