Commit f2252acf authored by Kemeng Shi's avatar Kemeng Shi Committed by Andrew Morton
Browse files

mm: swap: drop last SWAP_MAP_SHMEM flag in batch in swap_entries_put_nr() 

The SWAP_MAP_SHMEM indicates last map from shmem.  Therefore we can drop
SWAP_MAP_SHMEM in batch in similar way to drop last ref count in batch.

Link: https://lkml.kernel.org/r/20250325162528.68385-6-shikemeng@huaweicloud.com


Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: default avatarBaoquan He <bhe@redhat.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 46e0ab2c

mm/swapfile.c

+5 −2
Original line number Diff line number Diff line
@@ -192,7 +192,7 @@ static bool swap_is_last_map(struct swap_info_struct *si, 
	unsigned char *map_end = map + nr_pages;

	unsigned char count = *map;



	if (swap_count(count) != 1)

	if (swap_count(count) != 1 && swap_count(count) != SWAP_MAP_SHMEM)

		return false;



	while (++map < map_end) {
@@ -1487,7 +1487,10 @@ static bool swap_entries_put_nr(struct swap_info_struct *si, 
	unsigned char count;

	int i;



	if (nr <= 1 || swap_count(data_race(si->swap_map[offset])) != 1)

	if (nr <= 1)

		goto fallback;

	count = swap_count(data_race(si->swap_map[offset]));

	if (count != 1 && count != SWAP_MAP_SHMEM)

		goto fallback;

	/* cross into another cluster */

	if (nr > SWAPFILE_CLUSTER - offset % SWAPFILE_CLUSTER)