[dpdk-dev] [PATCH v6 2/2] examples/vhost: use API to check inflight packets

[Xuan Ding <xuan.ding@intel.com>]

In async data path, call rte_vhost_async_get_inflight_thread_unsafe()
API to directly return the number of inflight packets instead of
maintaining a local variable.

Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
 examples/vhost/main.c | 31 +++++++++++++++++--------------
 examples/vhost/main.h |  1 -
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index d0bf1f31e3..7a5d97cef6 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -842,11 +842,8 @@ complete_async_pkts(struct vhost_dev *vdev)
 
 	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
 					VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
-	if (complete_count) {
+	if (complete_count)
 		free_pkts(p_cpl, complete_count);
-		__atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
-	}
-
 }
 
 static __rte_always_inline void
@@ -886,7 +883,6 @@ drain_vhost(struct vhost_dev *vdev)
 
 		complete_async_pkts(vdev);
 		ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit);
-		__atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
 
 		enqueue_fail = nr_xmit - ret;
 		if (enqueue_fail)
@@ -1212,7 +1208,6 @@ drain_eth_rx(struct vhost_dev *vdev)
 		complete_async_pkts(vdev);
 		enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
 					VIRTIO_RXQ, pkts, rx_count);
-		__atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);
 
 		enqueue_fail = rx_count - enqueue_count;
 		if (enqueue_fail)
@@ -1384,13 +1379,17 @@ destroy_device(int vid)
 
 	if (async_vhost_driver) {
 		uint16_t n_pkt = 0;
-		struct rte_mbuf *m_cpl[vdev->pkts_inflight];
+		int pkts_inflight;
 
-		while (vdev->pkts_inflight) {
+		pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid, VIRTIO_RXQ);
+		struct rte_mbuf *m_cpl[pkts_inflight];
+
+		while (pkts_inflight) {
 			n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
-						m_cpl, vdev->pkts_inflight);
+						m_cpl, pkts_inflight);
 			free_pkts(m_cpl, n_pkt);
-			__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
+			pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid,
+									VIRTIO_RXQ);
 		}
 
 		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
@@ -1500,13 +1499,17 @@ vring_state_changed(int vid, uint16_t queue_id, int enable)
 	if (async_vhost_driver) {
 		if (!enable) {
 			uint16_t n_pkt = 0;
-			struct rte_mbuf *m_cpl[vdev->pkts_inflight];
+			int pkts_inflight;
+
+			pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id);
+			struct rte_mbuf *m_cpl[pkts_inflight];
 
-			while (vdev->pkts_inflight) {
+			while (pkts_inflight) {
 				n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
-							m_cpl, vdev->pkts_inflight);
+							m_cpl, pkts_inflight);
 				free_pkts(m_cpl, n_pkt);
-				__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
+				pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid,
+										queue_id);
 			}
 		}
 	}
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index e7b1ac60a6..0ccdce4b4a 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -51,7 +51,6 @@ struct vhost_dev {
 	uint64_t features;
 	size_t hdr_len;
 	uint16_t nr_vrings;
-	uint16_t pkts_inflight;
 	struct rte_vhost_memory *mem;
 	struct device_statistics stats;
 	TAILQ_ENTRY(vhost_dev) global_vdev_entry;
-- 
2.17.1