Since ci->lock has been taken when isolating cluster from
si->free_clusters or taking si->percpu_cluster->next[order],
it's unnecessary to scan and check the cluster range availability
if i'ts empty cluster, and this can accelerate the huge page
swapping.
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
mm/swapfile.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 9c9a4ec6d4c6..61efde853eea 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -729,6 +729,9 @@ static bool cluster_scan_range(struct swap_info_struct *si,
unsigned long offset, end = start + nr_pages;
unsigned char *map = si->swap_map;
+ if (cluster_is_empty(ci))
+ return true;
+
for (offset = start; offset < end; offset++) {
switch (READ_ONCE(map[offset])) {
case 0:
--
2.41.0
