From 63505186a070fcbd4e812f6b9cf67380fa7961d7 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 9 Aug 2013 14:19:32 +0100 Subject: dm space map disk: optimise sm_disk_dec_block Don't waste time spotting blocks that have been allocated and then freed in the same transaction. The extra lookup is expensive, and I don't think it really gives us much. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/persistent-data/dm-space-map-disk.c | 18 +----------------- 1 file changed, 1 insertion(+), 17 deletions(-) Index: linux/drivers/md/persistent-data/dm-space-map-disk.c =================================================================== --- linux.orig/drivers/md/persistent-data/dm-space-map-disk.c +++ linux/drivers/md/persistent-data/dm-space-map-disk.c @@ -140,26 +140,10 @@ static int sm_disk_inc_block(struct dm_s static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b) { - int r; - uint32_t old_count; enum allocation_event ev; struct sm_disk *smd = container_of(sm, struct sm_disk, sm); - r = sm_ll_dec(&smd->ll, b, &ev); - if (!r && (ev == SM_FREE)) { - /* - * It's only free if it's also free in the last - * transaction. - */ - r = sm_ll_lookup(&smd->old_ll, b, &old_count); - if (r) - return r; - - if (!old_count) - smd->nr_allocated_this_transaction--; - } - - return r; + return sm_ll_dec(&smd->ll, b, &ev); } static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)