mm: compaction: simplify the code in __compact_finished

Since commit efe771c ("mm, compaction: always finish scanning of a full pageblock"), compaction will always finish scanning a pageblock. And migrate_pfn is assured to align with pageblock_nr_pages when we reach here. So we will always return COMPACT_SUCCESS if a suitable fallback is found due to the below IS_ALIGNED check of migrate_pfn. Simplify the code to make this clear and improve the readability. No functional change intended. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Miaohe Lin <[email protected]> Cc: Charan Teja Kalla <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Pintu Kumar <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
wafgo · Apr 29, 2022 · fa599c4 · fa599c4
1 parent cff387d
commit fa599c4
Showing 1 changed file with 8 additions and 21 deletions.
diff --git a/mm/compaction.c b/mm/compaction.c
@@ -2134,29 +2134,16 @@ static enum compact_result __compact_finished(struct compact_control *cc)
 		 * other migratetype buddy lists.
 		 */
 		if (find_suitable_fallback(area, order, migratetype,
-						true, &can_steal) != -1) {
-
-			/* movable pages are OK in any pageblock */
-			if (migratetype == MIGRATE_MOVABLE)
-				return COMPACT_SUCCESS;
-
+						true, &can_steal) != -1)
 			/*
-			 * We are stealing for a non-movable allocation. Make
-			 * sure we finish compacting the current pageblock
-			 * first so it is as free as possible and we won't
-			 * have to steal another one soon. This only applies
-			 * to sync compaction, as async compaction operates
-			 * on pageblocks of the same migratetype.
+			 * Movable pages are OK in any pageblock. If we are
+			 * stealing for a non-movable allocation, make sure
+			 * we finish compacting the current pageblock first
+			 * (which is assured by the above migrate_pfn align
+			 * check) so it is as free as possible and we won't
+			 * have to steal another one soon.
 			 */
-			if (cc->mode == MIGRATE_ASYNC ||
-					IS_ALIGNED(cc->migrate_pfn,
-							pageblock_nr_pages)) {
-				return COMPACT_SUCCESS;
-			}
-
-			ret = COMPACT_CONTINUE;
-			break;
-		}
+			return COMPACT_SUCCESS;
 	}
 
 out: