[SCSI] qla2xxx: Add CPU affinity support.
Set the module parameter ql2xmultique_tag to 1 to enable this
feature. In this mode, the total number of response queues
created is equal to the number of online cpus. Turning the block
layer's rq_affinity mode on enables requests to be routed to the
proper cpu and at the same time it enables completion of the IO
in a response queue that is affined to the cpu in the request
path.
Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index 94b69d8..7b15ded 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -15,6 +15,7 @@
struct rsp_que *rsp);
static void qla2x00_isp_cmd(struct scsi_qla_host *, struct req_que *);
+static void qla25xx_set_que(srb_t *, struct req_que **, struct rsp_que **);
/**
* qla2x00_get_cmd_direction() - Determine control_flag data direction.
* @cmd: SCSI command
@@ -726,8 +727,7 @@
/* Setup device pointers. */
ret = 0;
- req = vha->req;
- rsp = ha->rsp_q_map[0];
+ qla25xx_set_que(sp, &req, &rsp);
sp->que = req;
/* So we know we haven't pci_map'ed anything yet */
@@ -850,3 +850,21 @@
return QLA_FUNCTION_FAILED;
}
+
+static void qla25xx_set_que(srb_t *sp, struct req_que **req,
+ struct rsp_que **rsp)
+{
+ struct scsi_cmnd *cmd = sp->cmd;
+ struct scsi_qla_host *vha = sp->fcport->vha;
+ struct qla_hw_data *ha = sp->fcport->vha->hw;
+ int affinity = cmd->request->cpu;
+
+ if (ql2xmultique_tag && affinity >= 0 &&
+ affinity < ha->max_rsp_queues - 1) {
+ *rsp = ha->rsp_q_map[affinity + 1];
+ *req = ha->req_q_map[1];
+ } else {
+ *req = vha->req;
+ *rsp = ha->rsp_q_map[0];
+ }
+}