scst/include/scst.h: Reduce the size of struct scst_cmd

Reduce the size of struct scst_cmd by reordering its structure members such
that there are two holes less in this data structure. This change has been
verified with the help of the 'pahole' tool.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@8606 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scst/include/scst.h

@@ -2135,12 +2135,12 @@ struct scst_cmd {
 	/* Assigned processing thread (for better CPU affinity) */
 	struct scst_cmd_thread_t *cmd_thr;
 
-	atomic_t cmd_ref;
-
 	struct scst_session *sess;	/* corresponding session */
 
 	atomic_t *cpu_cmd_counter;
 
+	atomic_t cmd_ref;
+
 	/* Cmd state, one of SCST_CMD_STATE_* constants */
 	enum scst_cmd_state state;
 
@@ -2357,9 +2357,6 @@ struct scst_cmd {
 	/* List entry for tgt_dev's deferred (SN, ACA, etc.) lists */
 	struct list_head deferred_cmd_list_entry;
 
-	/* Cmd's serial number, used to execute cmd's in order of arrival */
-	unsigned int sn;
-
 	/* The corresponding sn_slot in tgt_dev->sn_slots */
 	atomic_t *sn_slot;
 
@@ -2372,6 +2369,9 @@ struct scst_cmd {
 	 */
 	uint64_t tag;
 
+	/* Cmd's serial number, used to execute cmd's in order of arrival */
+	unsigned int sn;
+
 	uint32_t tgt_sn; /* SN set by target driver (for TM purposes) */
 
 	uint8_t *cdb; /* Pointer on CDB. Points on cdb_buf for small CDBs. */