On 8/4/2023 7:04 PM, Kemeng Shi wrote:
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@xxxxxxxxxxxxxxx>
LGTM.
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index 9a2f0bd5394a..4bf2dc936add 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1988,9 +1988,9 @@ 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
- * search was successful.
+ * fast_find_migrateblock() has already ensured the pageblock is not
+ * set with a skipped flag, 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;
