From: Mike Snitzer Move multipath structure's 'lock' and 'queue_size' members to eliminate 2 4-byte holes. Also use a bit within a single unsigned int for each existing flag (saves 8-bytes). This allows future flags to be added without each consuming an unsigned int. Signed-off-by: Mike Snitzer Acked-by: Hannes Reinecke --- drivers/md/dm-mpath.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) Index: linux-3.4/drivers/md/dm-mpath.c =================================================================== --- linux-3.4.orig/drivers/md/dm-mpath.c +++ linux-3.4/drivers/md/dm-mpath.c @@ -62,11 +62,11 @@ struct multipath { struct list_head list; struct dm_target *ti; - spinlock_t lock; - const char *hw_handler_name; char *hw_handler_params; + spinlock_t lock; + unsigned nr_priority_groups; struct list_head priority_groups; @@ -82,16 +82,17 @@ struct multipath { struct priority_group *next_pg; /* Switch to this PG if set */ unsigned repeat_count; /* I/Os left before calling PS again */ - unsigned queue_io; /* Must we queue all I/O? */ - unsigned queue_if_no_path; /* Queue I/O if last path fails? */ - unsigned saved_queue_if_no_path;/* Saved state during suspension */ + unsigned queue_io:1; /* Must we queue all I/O? */ + unsigned queue_if_no_path:1; /* Queue I/O if last path fails? */ + unsigned saved_queue_if_no_path:1; /* Saved state during suspension */ + unsigned pg_init_retries; /* Number of times to retry pg_init */ unsigned pg_init_count; /* Number of times pg_init called */ unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ + unsigned queue_size; struct work_struct process_queued_ios; struct list_head queued_ios; - unsigned queue_size; struct work_struct trigger_event;