From c9ec5d7c7b4c3d84bb1b39bc36c5992fceb15a91 Mon Sep 17 00:00:00 2001 From: Mike Snitzer <snitzer@redhat.com> Date: Fri, 16 Aug 2013 10:54:21 -0400 Subject: dm cache: eliminate holes in cache structure Reorder members in the cache structure to eliminate 6 out of 7 holes (reclaiming 24 bytes). Also, the 'worker' and 'waker' members no longer straddle cachelines. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> --- drivers/md/dm-cache-target.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 22ff650..2956976 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -103,6 +103,8 @@ struct cache { struct dm_target *ti; struct dm_target_callbacks callbacks; + struct dm_cache_metadata *cmd; + /* * Metadata is written to this device. */ @@ -119,11 +121,6 @@ struct cache { struct dm_dev *cache_dev; /* - * Cache features such as write-through. - */ - struct cache_features features; - - /* * Size of the origin device in _complete_ blocks and native sectors. */ dm_oblock_t origin_blocks; @@ -140,8 +137,6 @@ struct cache { uint32_t sectors_per_block; int sectors_per_block_shift; - struct dm_cache_metadata *cmd; - spinlock_t lock; struct bio_list deferred_bios; struct bio_list deferred_flush_bios; @@ -150,8 +145,8 @@ struct cache { struct list_head completed_migrations; struct list_head need_commit_migrations; sector_t migration_threshold; - atomic_t nr_migrations; wait_queue_head_t migration_wait; + atomic_t nr_migrations; /* * cache_size entries, dirty if set @@ -162,9 +157,16 @@ struct cache { /* * origin_blocks entries, discarded if set. */ - uint32_t discard_block_size; /* a power of 2 times sectors per block */ dm_dblock_t discard_nr_blocks; unsigned long *discard_bitset; + uint32_t discard_block_size; /* a power of 2 times sectors per block */ + + /* + * Rather than reconstructing the table line for the status we just + * save it and regurgitate. + */ + unsigned nr_ctr_args; + const char **ctr_args; struct dm_kcopyd_client *copier; struct workqueue_struct *wq; @@ -189,14 +191,12 @@ struct cache { bool loaded_mappings:1; bool loaded_discards:1; - struct cache_stats stats; - /* - * Rather than reconstructing the table line for the status we just - * save it and regurgitate. + * Cache features such as write-through. */ - unsigned nr_ctr_args; - const char **ctr_args; + struct cache_features features; + + struct cache_stats stats; }; struct per_bio_data { -- cgit v1.1