[dpdk-dev] [PATCH v1 2/3] examples/vhost: optimize vhost data path for batch
Cheng Jiang
Cheng1.jiang at intel.com
Fri Dec 18 12:33:26 CET 2020
Change the vm2vm data path to batch enqueue for better performance.
Signed-off-by: Cheng Jiang <Cheng1.jiang at intel.com>
---
examples/vhost/main.c | 84 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 75 insertions(+), 9 deletions(-)
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 8d8c3038bf..28226a4ff7 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -182,6 +182,11 @@ struct mbuf_table {
/* TX queue for each data core. */
struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];
+static uint64_t vhost_tsc[MAX_VHOST_DEVICE];
+
+/* TX queue for each vhost device. */
+struct mbuf_table vhost_m_table[MAX_VHOST_DEVICE];
+
#define MBUF_TABLE_DRAIN_TSC ((rte_get_tsc_hz() + US_PER_S - 1) \
/ US_PER_S * BURST_TX_DRAIN_US)
#define VLAN_HLEN 4
@@ -804,6 +809,13 @@ unlink_vmdq(struct vhost_dev *vdev)
}
}
+static inline void
+free_pkts(struct rte_mbuf **pkts, uint16_t n)
+{
+ while (n--)
+ rte_pktmbuf_free(pkts[n]);
+}
+
static __rte_always_inline void
virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
struct rte_mbuf *m)
@@ -837,6 +849,40 @@ virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
}
}
+static __rte_always_inline void
+drain_vhost(struct vhost_dev *dst_vdev, struct rte_mbuf **m, uint16_t nr_xmit)
+{
+ uint16_t ret, nr_cpl;
+ struct rte_mbuf *m_cpl[MAX_PKT_BURST];
+
+ if (builtin_net_driver) {
+ ret = vs_enqueue_pkts(dst_vdev, VIRTIO_RXQ, m, nr_xmit);
+ } else if (async_vhost_driver) {
+ ret = rte_vhost_submit_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ,
+ m, nr_xmit);
+ dst_vdev->nr_async_pkts += ret;
+ free_pkts(&m[ret], nr_xmit - ret);
+
+ while (likely(dst_vdev->nr_async_pkts)) {
+ nr_cpl = rte_vhost_poll_enqueue_completed(dst_vdev->vid,
+ VIRTIO_RXQ, m_cpl, MAX_PKT_BURST);
+ dst_vdev->nr_async_pkts -= nr_cpl;
+ free_pkts(m_cpl, nr_cpl);
+ }
+ } else {
+ ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ,
+ m, nr_xmit);
+ }
+
+ if (enable_stats) {
+ rte_atomic64_add(&dst_vdev->stats.rx_total_atomic, nr_xmit);
+ rte_atomic64_add(&dst_vdev->stats.rx_atomic, ret);
+ }
+
+ if (!async_vhost_driver)
+ free_pkts(m, nr_xmit);
+}
+
/*
* Check if the packet destination MAC address is for a local device. If so then put
* the packet on that devices RX queue. If not then return.
@@ -846,6 +892,7 @@ virtio_tx_local(struct vhost_dev *vdev, struct rte_mbuf *m)
{
struct rte_ether_hdr *pkt_hdr;
struct vhost_dev *dst_vdev;
+ struct mbuf_table *vhost_txq;
pkt_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
@@ -869,7 +916,19 @@ virtio_tx_local(struct vhost_dev *vdev, struct rte_mbuf *m)
return 0;
}
- virtio_xmit(dst_vdev, vdev, m);
+ vhost_txq = &vhost_m_table[dst_vdev->vid];
+ vhost_txq->m_table[vhost_txq->len++] = m;
+
+ if (enable_stats) {
+ vdev->stats.tx_total++;
+ vdev->stats.tx++;
+ }
+
+ if (unlikely(vhost_txq->len == MAX_PKT_BURST)) {
+ drain_vhost(dst_vdev, vhost_txq->m_table, MAX_PKT_BURST);
+ vhost_txq->len = 0;
+ vhost_tsc[dst_vdev->vid] = rte_rdtsc();
+ }
return 0;
}
@@ -940,13 +999,6 @@ static void virtio_tx_offload(struct rte_mbuf *m)
tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
}
-static inline void
-free_pkts(struct rte_mbuf **pkts, uint16_t n)
-{
- while (n--)
- rte_pktmbuf_free(pkts[n]);
-}
-
static __rte_always_inline void
do_drain_mbuf_table(struct mbuf_table *tx_q)
{
@@ -986,7 +1038,6 @@ virtio_tx_route(struct vhost_dev *vdev, struct rte_mbuf *m, uint16_t vlan_tag)
/*check if destination is local VM*/
if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev, m) == 0)) {
- rte_pktmbuf_free(m);
return;
}
@@ -1144,8 +1195,10 @@ static __rte_always_inline void
drain_virtio_tx(struct vhost_dev *vdev)
{
struct rte_mbuf *pkts[MAX_PKT_BURST];
+ struct mbuf_table *vhost_txq;
uint16_t count;
uint16_t i;
+ uint64_t cur_tsc;
if (builtin_net_driver) {
count = vs_dequeue_pkts(vdev, VIRTIO_TXQ, mbuf_pool,
@@ -1163,6 +1216,19 @@ drain_virtio_tx(struct vhost_dev *vdev)
for (i = 0; i < count; ++i)
virtio_tx_route(vdev, pkts[i], vlan_tags[vdev->vid]);
+
+ vhost_txq = &vhost_m_table[vdev->vid];
+ cur_tsc = rte_rdtsc();
+ if (unlikely(cur_tsc - vhost_tsc[vdev->vid] > MBUF_TABLE_DRAIN_TSC)) {
+ if (vhost_txq->len) {
+ RTE_LOG_DP(DEBUG, VHOST_DATA,
+ "Vhost tX queue drained after timeout with burst size %u\n",
+ vhost_txq->len);
+ drain_vhost(vdev, vhost_txq->m_table, vhost_txq->len);
+ vhost_txq->len = 0;
+ vhost_tsc[vdev->vid] = cur_tsc;
+ }
+ }
}
/*
--
2.29.2
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