[dpdk-dev] [PATCH v2 10/15] net/enic: reduce Tx completion updates
John Daley
johndale at cisco.com
Fri Jun 29 11:29:39 CEST 2018
From: Hyong Youb Kim <hyonkim at cisco.com>
Request one completion update per roughly 32 buffers. It saves DMA
resources on the NIC, PCIe utilization, and cache miss rates.
Signed-off-by: Hyong Youb Kim <hyonkim at cisco.com>
Reviewed-by: John Daley <johndale at cisco.com>
---
drivers/net/enic/base/vnic_wq.c | 1 +
drivers/net/enic/base/vnic_wq.h | 1 +
drivers/net/enic/enic_res.h | 3 +++
drivers/net/enic/enic_rxtx.c | 23 +++++++++++++++++------
4 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/net/enic/base/vnic_wq.c b/drivers/net/enic/base/vnic_wq.c
index a4c08a769..c9bf3572c 100644
--- a/drivers/net/enic/base/vnic_wq.c
+++ b/drivers/net/enic/base/vnic_wq.c
@@ -113,6 +113,7 @@ void vnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
vnic_wq_init_start(wq, cq_index, 0, 0,
error_interrupt_enable,
error_interrupt_offset);
+ wq->cq_pend = 0;
wq->last_completed_index = 0;
}
diff --git a/drivers/net/enic/base/vnic_wq.h b/drivers/net/enic/base/vnic_wq.h
index 6622a8a2d..236cf6962 100644
--- a/drivers/net/enic/base/vnic_wq.h
+++ b/drivers/net/enic/base/vnic_wq.h
@@ -44,6 +44,7 @@ struct vnic_wq {
struct vnic_dev_ring ring;
struct rte_mbuf **bufs;
unsigned int head_idx;
+ unsigned int cq_pend;
unsigned int tail_idx;
unsigned int socket_id;
const struct rte_memzone *cqmsg_rz;
diff --git a/drivers/net/enic/enic_res.h b/drivers/net/enic/enic_res.h
index 6a3a0c5cc..6b1f6acad 100644
--- a/drivers/net/enic/enic_res.h
+++ b/drivers/net/enic/enic_res.h
@@ -20,6 +20,9 @@
#define ENIC_ALIGN_DESCS 32
#define ENIC_ALIGN_DESCS_MASK ~(ENIC_ALIGN_DESCS - 1)
+/* Request a completion index every 32 buffers (roughly packets) */
+#define ENIC_WQ_CQ_THRESH 32
+
#define ENIC_MIN_MTU 68
/* Does not include (possible) inserted VLAN tag and FCS */
diff --git a/drivers/net/enic/enic_rxtx.c b/drivers/net/enic/enic_rxtx.c
index 89a1e66fe..7cddb53d9 100644
--- a/drivers/net/enic/enic_rxtx.c
+++ b/drivers/net/enic/enic_rxtx.c
@@ -603,7 +603,7 @@ uint16_t enic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
struct wq_enet_desc *descs, *desc_p, desc_tmp;
uint16_t mss;
uint8_t vlan_tag_insert;
- uint8_t eop;
+ uint8_t eop, cq;
uint64_t bus_addr;
uint8_t offload_mode;
uint16_t header_len;
@@ -686,10 +686,14 @@ uint16_t enic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
break;
}
}
-
-
+ wq->cq_pend++;
+ cq = 0;
+ if (eop && wq->cq_pend >= ENIC_WQ_CQ_THRESH) {
+ cq = 1;
+ wq->cq_pend = 0;
+ }
wq_enet_desc_enc(&desc_tmp, bus_addr, data_len, mss, header_len,
- offload_mode, eop, eop, 0, vlan_tag_insert,
+ offload_mode, eop, cq, 0, vlan_tag_insert,
vlan_id, 0);
*desc_p = desc_tmp;
@@ -702,14 +706,21 @@ uint16_t enic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
tx_pkt->next) {
data_len = tx_pkt->data_len;
- if (tx_pkt->next == NULL)
+ wq->cq_pend++;
+ cq = 0;
+ if (tx_pkt->next == NULL) {
eop = 1;
+ if (wq->cq_pend >= ENIC_WQ_CQ_THRESH) {
+ cq = 1;
+ wq->cq_pend = 0;
+ }
+ }
desc_p = descs + head_idx;
bus_addr = (dma_addr_t)(tx_pkt->buf_iova
+ tx_pkt->data_off);
wq_enet_desc_enc((struct wq_enet_desc *)
&desc_tmp, bus_addr, data_len,
- mss, 0, offload_mode, eop, eop,
+ mss, 0, offload_mode, eop, cq,
0, vlan_tag_insert, vlan_id,
0);
--
2.16.2
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