diff --git a/mm/compaction.c b/mm/compaction.c
index e2618ac..bbf41ee 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1391,11 +1391,10 @@
 		return COMPACT_SUCCESS;
 
 	/*
-	 * Watermarks for order-0 must be met for compaction. Note the 2UL.
-	 * This is because during migration, copies of pages need to be
-	 * allocated and for a short time, the footprint is higher
+	 * Watermarks for order-0 must be met for compaction to be able to
+	 * isolate free pages for migration targets.
 	 */
-	watermark = low_wmark_pages(zone) + (2UL << order);
+	watermark = low_wmark_pages(zone) + compact_gap(order);
 	if (!__zone_watermark_ok(zone, 0, watermark, classzone_idx,
 				 alloc_flags, wmark_target))
 		return COMPACT_SKIPPED;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 981fc84..2a6978a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2480,7 +2480,7 @@
 	 * If we have not reclaimed enough pages for compaction and the
 	 * inactive lists are large enough, continue reclaiming
 	 */
-	pages_for_compaction = (2UL << sc->order);
+	pages_for_compaction = compact_gap(sc->order);
 	inactive_lru_pages = node_page_state(pgdat, NR_INACTIVE_FILE);
 	if (get_nr_swap_pages() > 0)
 		inactive_lru_pages += node_page_state(pgdat, NR_INACTIVE_ANON);
@@ -2612,7 +2612,7 @@
 	 * there is a buffer of free pages available to give compaction
 	 * a reasonable chance of completing and allocating the page
 	 */
-	watermark = high_wmark_pages(zone) + (2UL << sc->order);
+	watermark = high_wmark_pages(zone) + compact_gap(sc->order);
 	watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, sc->reclaim_idx);
 
 	/*
@@ -3169,7 +3169,7 @@
 	 * excessive reclaim. Assume that a process requested a high-order
 	 * can direct reclaim/compact.
 	 */
-	if (sc->order && sc->nr_reclaimed >= 2UL << sc->order)
+	if (sc->order && sc->nr_reclaimed >= compact_gap(sc->order))
 		sc->order = 0;
 
 	return sc->nr_scanned >= sc->nr_to_reclaim;