IB/srp: Split send and recieve CQs to reduce number of interrupts
We can reduce the number of IB interrupts from two interrupts per
srp_queuecommand() call to one by using separate CQs for send and
receive completions and processing send completions by polling every
time a TX IU is allocated.
Receive completion events still trigger an interrupt.
Signed-off-by: Bart Van Assche <bart.vanassche@gmail.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 54c8fe2..441ea7c 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -80,7 +80,8 @@
static void srp_add_one(struct ib_device *device);
static void srp_remove_one(struct ib_device *device);
-static void srp_completion(struct ib_cq *cq, void *target_ptr);
+static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
+static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
static struct scsi_transport_template *ib_srp_transport_template;
@@ -227,14 +228,22 @@
if (!init_attr)
return -ENOMEM;
- target->cq = ib_create_cq(target->srp_host->srp_dev->dev,
- srp_completion, NULL, target, SRP_CQ_SIZE, 0);
- if (IS_ERR(target->cq)) {
- ret = PTR_ERR(target->cq);
+ target->recv_cq = ib_create_cq(target->srp_host->srp_dev->dev,
+ srp_recv_completion, NULL, target, SRP_RQ_SIZE, 0);
+ if (IS_ERR(target->recv_cq)) {
+ ret = PTR_ERR(target->recv_cq);
goto out;
}
- ib_req_notify_cq(target->cq, IB_CQ_NEXT_COMP);
+ target->send_cq = ib_create_cq(target->srp_host->srp_dev->dev,
+ srp_send_completion, NULL, target, SRP_SQ_SIZE, 0);
+ if (IS_ERR(target->send_cq)) {
+ ret = PTR_ERR(target->send_cq);
+ ib_destroy_cq(target->recv_cq);
+ goto out;
+ }
+
+ ib_req_notify_cq(target->recv_cq, IB_CQ_NEXT_COMP);
init_attr->event_handler = srp_qp_event;
init_attr->cap.max_send_wr = SRP_SQ_SIZE;
@@ -243,20 +252,22 @@
init_attr->cap.max_send_sge = 1;
init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
init_attr->qp_type = IB_QPT_RC;
- init_attr->send_cq = target->cq;
- init_attr->recv_cq = target->cq;
+ init_attr->send_cq = target->send_cq;
+ init_attr->recv_cq = target->recv_cq;
target->qp = ib_create_qp(target->srp_host->srp_dev->pd, init_attr);
if (IS_ERR(target->qp)) {
ret = PTR_ERR(target->qp);
- ib_destroy_cq(target->cq);
+ ib_destroy_cq(target->send_cq);
+ ib_destroy_cq(target->recv_cq);
goto out;
}
ret = srp_init_qp(target, target->qp);
if (ret) {
ib_destroy_qp(target->qp);
- ib_destroy_cq(target->cq);
+ ib_destroy_cq(target->send_cq);
+ ib_destroy_cq(target->recv_cq);
goto out;
}
@@ -270,7 +281,8 @@
int i;
ib_destroy_qp(target->qp);
- ib_destroy_cq(target->cq);
+ ib_destroy_cq(target->send_cq);
+ ib_destroy_cq(target->recv_cq);
for (i = 0; i < SRP_RQ_SIZE; ++i)
srp_free_iu(target->srp_host, target->rx_ring[i]);
@@ -568,7 +580,9 @@
if (ret)
goto err;
- while (ib_poll_cq(target->cq, 1, &wc) > 0)
+ while (ib_poll_cq(target->recv_cq, 1, &wc) > 0)
+ ; /* nothing */
+ while (ib_poll_cq(target->send_cq, 1, &wc) > 0)
; /* nothing */
spin_lock_irq(target->scsi_host->host_lock);
@@ -851,7 +865,7 @@
struct srp_iu *iu;
u8 opcode;
- iu = target->rx_ring[wc->wr_id & ~SRP_OP_RECV];
+ iu = target->rx_ring[wc->wr_id];
dev = target->srp_host->srp_dev->dev;
ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_ti_iu_len,
@@ -898,7 +912,7 @@
DMA_FROM_DEVICE);
}
-static void srp_completion(struct ib_cq *cq, void *target_ptr)
+static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
{
struct srp_target_port *target = target_ptr;
struct ib_wc wc;
@@ -907,17 +921,31 @@
while (ib_poll_cq(cq, 1, &wc) > 0) {
if (wc.status) {
shost_printk(KERN_ERR, target->scsi_host,
- PFX "failed %s status %d\n",
- wc.wr_id & SRP_OP_RECV ? "receive" : "send",
+ PFX "failed receive status %d\n",
wc.status);
target->qp_in_error = 1;
break;
}
- if (wc.wr_id & SRP_OP_RECV)
- srp_handle_recv(target, &wc);
- else
- ++target->tx_tail;
+ srp_handle_recv(target, &wc);
+ }
+}
+
+static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
+{
+ struct srp_target_port *target = target_ptr;
+ struct ib_wc wc;
+
+ while (ib_poll_cq(cq, 1, &wc) > 0) {
+ if (wc.status) {
+ shost_printk(KERN_ERR, target->scsi_host,
+ PFX "failed send status %d\n",
+ wc.status);
+ target->qp_in_error = 1;
+ break;
+ }
+
+ ++target->tx_tail;
}
}
@@ -930,7 +958,7 @@
int ret;
next = target->rx_head & (SRP_RQ_SIZE - 1);
- wr.wr_id = next | SRP_OP_RECV;
+ wr.wr_id = next;
iu = target->rx_ring[next];
list.addr = iu->dma;
@@ -970,6 +998,8 @@
{
s32 min = (req_type == SRP_REQ_TASK_MGMT) ? 1 : 2;
+ srp_send_completion(target->send_cq, target);
+
if (target->tx_head - target->tx_tail >= SRP_SQ_SIZE)
return NULL;