dm: eliminate some holes data structures
Eliminate a 4-byte hole in 'struct dm_io_memory' by moving 'offset' above the
'ptr' to which it applies (size reduced from 24 to 16 bytes). And by
association, 1-4 byte hole is eliminated in 'struct dm_io_request' (size
reduced from 56 to 48 bytes).
Eliminate all 6 4-byte holes and 1 cache-line in 'struct dm_snapshot' (size
reduced from 392 to 368 bytes).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 0789c22..5485377 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -83,10 +83,10 @@
/* Whether or not owning mapped_device is suspended */
int suspended;
- mempool_t *pending_pool;
-
atomic_t pending_exceptions_count;
+ mempool_t *pending_pool;
+
struct dm_exception_table pending;
struct dm_exception_table complete;
@@ -96,6 +96,11 @@
*/
spinlock_t pe_lock;
+ /* Chunks with outstanding reads */
+ spinlock_t tracked_chunk_lock;
+ mempool_t *tracked_chunk_pool;
+ struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
+
/* The on disk metadata handler */
struct dm_exception_store *store;
@@ -105,10 +110,12 @@
struct bio_list queued_bios;
struct work_struct queued_bios_work;
- /* Chunks with outstanding reads */
- mempool_t *tracked_chunk_pool;
- spinlock_t tracked_chunk_lock;
- struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
+ /* Wait for events based on state_bits */
+ unsigned long state_bits;
+
+ /* Range of chunks currently being merged. */
+ chunk_t first_merging_chunk;
+ int num_merging_chunks;
/*
* The merge operation failed if this flag is set.
@@ -125,13 +132,6 @@
*/
int merge_failed;
- /* Wait for events based on state_bits */
- unsigned long state_bits;
-
- /* Range of chunks currently being merged. */
- chunk_t first_merging_chunk;
- int num_merging_chunks;
-
/*
* Incoming bios that overlap with chunks being merged must wait
* for them to be committed.