[PATCH v2 4/4] mm: zswap: skip zswap_invalidate() in swap_range_free() when zswap is unused

[Kefeng Wang <wangkefeng.wang@huawei.com>]

swap_range_free() calls zswap_invalidate() for every slot being
freed, even when zswap has never been enabled. Guard the loop with
zswap_never_enabled() to skip it.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/swapfile.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index ba71905e4d46..505592051924 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1318,8 +1318,10 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
 	void (*swap_slot_free_notify)(struct block_device *, unsigned long);
 	unsigned int i;
 
-	for (i = 0; i < nr_entries; i++)
-		zswap_invalidate(si->type, offset + i);
+	if (!zswap_never_enabled()) {
+		for (i = 0; i < nr_entries; i++)
+			zswap_invalidate(si->type, offset + i);
+	}
 
 	if (si->flags & SWP_BLKDEV)
 		swap_slot_free_notify =
-- 
2.55.0