vhost: remove retry logic

It was used to wait some time and retry when there are not enough descriptors.
App could implement this policy easily if it needs.

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
Acked-by: Changchun Ouyang <changchun.ouyang@intel.com>

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 5ae0f9c..b0df32d 100644 (file)
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -99,7 +99,6 @@ virtio_dev_rx(struct virtio_net *dev, struct rte_mbuf **pkts, uint32_t count)
        uint64_t buff_hdr_addr = 0;
        uint32_t head[MAX_PKT_BURST], packet_len = 0;
        uint32_t head_idx, packet_success = 0;
-       uint32_t retry = 0;
        uint16_t avail_idx, res_cur_idx;
        uint16_t res_base_idx, res_end_idx;
        uint16_t free_entries;
@@ -115,18 +114,6 @@ virtio_dev_rx(struct virtio_net *dev, struct rte_mbuf **pkts, uint32_t count)
                avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 
                free_entries = (avail_idx - res_base_idx);
-               /* If retry is enabled and the queue is full then we wait and retry to avoid packet loss. */
-               if (enable_retry && unlikely(count > free_entries)) {
-                       for (retry = 0; retry < burst_rx_retry_num; retry++) {
-                               rte_delay_us(burst_rx_delay_time);
-                               avail_idx =
-                                       *((volatile uint16_t *)&vq->avail->idx);
-                               free_entries = (avail_idx - res_base_idx);
-                               if (count <= free_entries)
-                                       break;
-                       }
-               }
-
                /*check that we have enough buffers*/
                if (unlikely(count > free_entries))
                        count = free_entries;
@@ -440,7 +427,6 @@ virtio_dev_merge_rx(struct virtio_net *dev, struct rte_mbuf **pkts,
 {
        struct vhost_virtqueue *vq;
        uint32_t pkt_idx = 0, entry_success = 0;
-       uint32_t retry = 0;
        uint16_t avail_idx, res_cur_idx;
        uint16_t res_base_idx, res_end_idx;
        uint8_t success = 0;
@@ -471,26 +457,6 @@ virtio_dev_merge_rx(struct virtio_net *dev, struct rte_mbuf **pkts,
                        do {
                                avail_idx = *((volatile uint16_t *)&vq->avail->idx);
                                if (unlikely(res_cur_idx == avail_idx)) {
-                                       /*
-                                        * If retry is enabled and the queue is
-                                        * full then we wait and retry to avoid
-                                        * packet loss.
-                                        */
-                                       if (enable_retry) {
-                                               uint8_t cont = 0;
-                                               for (retry = 0; retry < burst_rx_retry_num; retry++) {
-                                                       rte_delay_us(burst_rx_delay_time);
-                                                       avail_idx =
-                                                               *((volatile uint16_t *)&vq->avail->idx);
-                                                       if (likely(res_cur_idx != avail_idx)) {
-                                                               cont = 1;
-                                                               break;
-                                                       }
-                                               }
-                                               if (cont == 1)
-                                                       continue;
-                                       }
-
                                        LOG_DEBUG(VHOST_DATA,
                                                "(%"PRIu64") Failed "
                                                "to get enough desc from "