On Wed, 12 Oct 2005, Chen, Kenneth W wrote:
> Patrick Mansfield wrote on Wednesday, October 12, 2005 1:00 PM
> > > > It turns out that qla2x00 driver unnecessarily activated
> > > > generic blk tag queue without actually use any of the tag
> > > > maintained by the block layer. I suggest we turn that off
> > > > until there is a real consumer of the tag queuing in the
> > > > qla driver. Please apply.
> > > >
> > > > Signed-off-by: Ken Chen <kenneth.w.chen@xxxxxxxxx>
> > >
> > > ACK.
> >
> > And then also remove scsi_populate_tag_msg() calls also in qla2xxx,
> > as that becomes dead code?
>
> Yeah, that would indeed be a very good thing to do. It reminds me
> a while back, I was investigating cache miss profile and we
> consistently see cache misses on tag[2] variable defined in
> qla2x00_start_scsi (used by scsi_populate_tag_msg). Removing it
> would be a very good thing for driver performance.
>
> Should I generate the patch?
Drop scsi_populate_tag_msg() interrogation.
Signed-off-by: Andrew Vasquez <andrew.vasquez@xxxxxxxxxx>
---
diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index 37f82e2..f5902ec 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -401,18 +401,6 @@ qla2x00_start_scsi(srb_t *sp)
/* Update tagged queuing modifier */
cmd_pkt->control_flags = __constant_cpu_to_le16(CF_SIMPLE_TAG);
- if (scsi_populate_tag_msg(cmd, tag)) {
- switch (tag[0]) {
- case MSG_HEAD_TAG:
- cmd_pkt->control_flags =
- __constant_cpu_to_le16(CF_HEAD_TAG);
- break;
- case MSG_ORDERED_TAG:
- cmd_pkt->control_flags =
- __constant_cpu_to_le16(CF_ORDERED_TAG);
- break;
- }
- }
/* Load SCSI command packet. */
memcpy(cmd_pkt->scsi_cdb, cmd->cmnd, cmd->cmd_len);
@@ -824,6 +812,7 @@ qla24xx_start_scsi(srb_t *sp)
cmd_pkt->handle = handle;
/* Zero out remaining portion of packet. */
+ /* tagged queuing modifier -- default is TSK_SIMPLE (0). */
clr_ptr = (uint32_t *)cmd_pkt + 2;
memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);
@@ -837,18 +826,6 @@ qla24xx_start_scsi(srb_t *sp)
cmd_pkt->lun[1] = LSB(sp->cmd->device->lun);
cmd_pkt->lun[2] = MSB(sp->cmd->device->lun);
- /* Update tagged queuing modifier -- default is TSK_SIMPLE (0). */
- if (scsi_populate_tag_msg(cmd, tag)) {
- switch (tag[0]) {
- case MSG_HEAD_TAG:
- cmd_pkt->task = TSK_HEAD_OF_QUEUE;
- break;
- case MSG_ORDERED_TAG:
- cmd_pkt->task = TSK_ORDERED;
- break;
- }
- }
-
/* Load SCSI command packet. */
memcpy(cmd_pkt->fcp_cdb, cmd->cmnd, cmd->cmd_len);
host_to_fcp_swap(cmd_pkt->fcp_cdb, sizeof(cmd_pkt->fcp_cdb));
-
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