[SCSI] libfc: cache align struct fc_fcp_pkt fields

Re-arrange its fields to avoid padding and have better
cacheline alignments.

Removed not used start_time, end_time and last_pkt_time
fields.

This all reduced this struct size to 448 from 480 and
that also reduced one cacheline on x86_64 beside
eliminating 8 pads. However kept logical fields together.

Signed-off-by: Vasu Dev <[email protected]>
Tested-by: Ross Brattain <[email protected]>
Signed-off-by: Yi Zou <[email protected]>
Signed-off-by: James Bottomley <[email protected]>

drivers/scsi/libfc/fc_fcp.c

@@ -759,7 +759,6 @@ static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 		goto out;
 	if (fc_fcp_lock_pkt(fsp))
 		goto out;
-	fsp->last_pkt_time = jiffies;
 
 	if (fh->fh_type == FC_TYPE_BLS) {
 		fc_fcp_abts_resp(fsp, fp);
@@ -1148,7 +1147,6 @@ static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
 		rc = -1;
 		goto unlock;
 	}
-	fsp->last_pkt_time = jiffies;
 	fsp->seq_ptr = seq;
 	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
 

include/scsi/libfc.h

@@ -281,9 +281,6 @@ struct fc_seq_els_data {
  * @timer:           The command timer
  * @tm_done:         Completion indicator
  * @wait_for_comp:   Indicator to wait for completion of the I/O (in jiffies)
- * @start_time:      Timestamp indicating the start of the I/O (in jiffies)
- * @end_time:        Timestamp indicating the end of the I/O (in jiffies)
- * @last_pkt_time:   Timestamp of the last frame received (in jiffies)
  * @data_len:        The length of the data
  * @cdb_cmd:         The CDB command
  * @xfer_len:        The transfer length
@@ -304,50 +301,46 @@ struct fc_seq_els_data {
  * @recov_seq:       The sequence for REC or SRR
  */
 struct fc_fcp_pkt {
-	/* Housekeeping information */
-	struct fc_lport   *lp;
-	u16		  state;
-	atomic_t	  ref_cnt;
 	spinlock_t	  scsi_pkt_lock;
+	atomic_t	  ref_cnt;
+
+	/* SCSI command and data transfer information */
+	u32		  data_len;
 
 	/* SCSI I/O related information */
 	struct scsi_cmnd  *cmd;
 	struct list_head  list;
 
-	/* Timeout related information */
-	struct timer_list timer;
-	struct completion tm_done;
-	int	          wait_for_comp;
-	unsigned long	  start_time;
-	unsigned long	  end_time;
-	unsigned long	  last_pkt_time;
-
-	/* SCSI command and data transfer information */
-	u32		  data_len;
-
-	/* Transport related veriables */
-	struct fcp_cmnd   cdb_cmd;
-	size_t		  xfer_len;
-	u16		  xfer_ddp;
-	u32		  xfer_contig_end;
-	u16		  max_payload;
+	/* Housekeeping information */
+	struct fc_lport   *lp;
+	u8		  state;
 
 	/* SCSI/FCP return status */
-	u32		  io_status;
 	u8		  cdb_status;
 	u8		  status_code;
 	u8		  scsi_comp_flags;
+	u32		  io_status;
 	u32		  req_flags;
 	u32		  scsi_resid;
 
+	/* Transport related veriables */
+	size_t		  xfer_len;
+	struct fcp_cmnd   cdb_cmd;
+	u32		  xfer_contig_end;
+	u16		  max_payload;
+	u16		  xfer_ddp;
+
 	/* Associated structures */
 	struct fc_rport	  *rport;
 	struct fc_seq	  *seq_ptr;
 
-	/* Error Processing information */
-	u8		  recov_retry;
+	/* Timeout/error related information */
+	struct timer_list timer;
+	int	          wait_for_comp;
+	u32		  recov_retry;
 	struct fc_seq	  *recov_seq;
-};
+	struct completion tm_done;
+} ____cacheline_aligned_in_smp;
 
 /*
  * Structure and function definitions for managing Fibre Channel Exchanges