mm: compaction: clean up comment about async compaction in isolate_migratepages

Since commit 282722b0d258 ("mm, compaction: restrict async compaction to
pageblocks of same migratetype"), async direct compaction is restricted to
scan the pageblocks of same migratetype.  Correct the comment accordingly.

Link: https://lkml.kernel.org/r/20220418141253.24298-9-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/compaction.c b/mm/compaction.c
index 55013a2..562f274 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1941,12 +1941,12 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc)
                        continue;
 
                /*
-                * For async compaction, also only scan in MOVABLE blocks
-                * without huge pages. Async compaction is optimistic to see
-                * if the minimum amount of work satisfies the allocation.
-                * The cached PFN is updated as it's possible that all
-                * remaining blocks between source and target are unsuitable
-                * and the compaction scanners fail to meet.
+                * For async direct compaction, only scan the pageblocks of the
+                * same migratetype without huge pages. Async direct compaction
+                * is optimistic to see if the minimum amount of work satisfies
+                * the allocation. The cached PFN is updated as it's possible
+                * that all remaining blocks between source and target are
+                * unsuitable and the compaction scanners fail to meet.
                 */
                if (!suitable_migration_source(cc, page)) {
                        update_cached_migrate(cc, block_end_pfn);