Commit 991bd8d7 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm writecache: commit just one block, not a full page 



Some architectures have pages larger than 4k and committing a full
page causes needless overhead.

Fix this by writing a single block when committing the superblock.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 620cbe40

drivers/md/dm-writecache.c

+1 −5
Original line number Diff line number Diff line
@@ -532,11 +532,7 @@ static void ssd_commit_superblock(struct dm_writecache *wc) 


	region.bdev = wc->ssd_dev->bdev;

	region.sector = 0;

	region.count = PAGE_SIZE >> SECTOR_SHIFT;



	if (unlikely(region.sector + region.count > wc->metadata_sectors))

		region.count = wc->metadata_sectors - region.sector;



	region.count = wc->block_size >> SECTOR_SHIFT;

	region.sector += wc->start_sector;



	req.bi_op = REQ_OP_WRITE;