[PATCH v2 4/8] mm/compaction: correct comment of fast_find_migrateblock in isolate_migratepages

[Kemeng Shi <shikemeng@huaweicloud.com>]

After 90ed667c03fe5 ("Revert "Revert "mm/compaction: fix set skip in
fast_find_migrateblock"""), we remove skip set in fast_find_migrateblock.
Correct comment that fast_find_block is used to avoid isolation_suitable
check for pageblock returned from fast_find_migrateblock because
fast_find_migrateblock will mark found pageblock skipped.
Instead, comment that fast_find_block is used to avoid a redundant check
of fast found pageblock which is already checked skip flag inside
fast_find_migrateblock.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 mm/compaction.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 984c17a5c8fd..5c9dc4049e8e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1966,8 +1966,8 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc)
 		block_start_pfn = cc->zone->zone_start_pfn;
 
 	/*
-	 * fast_find_migrateblock marks a pageblock skipped so to avoid
-	 * the isolation_suitable check below, check whether the fast
+	 * fast_find_migrateblock will ignore pageblock skipped, so to avoid
+	 * the isolation_suitable check below again, check whether the fast
 	 * search was successful.
 	 */
 	fast_find_block = low_pfn != cc->migrate_pfn && !cc->fast_search_fail;
-- 
2.30.0