[dpdk-dev] [PATCH] net/virtio: fix vectorized Rx queue stuck

[Xueming Li]

When Rx burst size >= Rx queue size, all descriptors in used queue
consumed without rearm, the next Rx burst found no new packets and
returned directly without rearm as well.

This patch rearms available queue at once after rx_burst to avoid vq
hungry.

Fixes: fc3d66212fed ("virtio: add vector Rx")
Cc: huawei....@intel.com
Fixes: 2d7c37194ee4 ("net/virtio: add NEON based Rx handler")
Cc: jerin.ja...@caviumnetworks.com
Fixes: 52b5a707e6ca ("net/virtio: add Altivec Rx")
Cc: d...@linux.vnet.ibm.com
Cc: sta...@dpdk.org

Signed-off-by: Xueming Li <xuemi...@nvidia.com>
---
 drivers/net/virtio/virtio_rxtx_simple_altivec.c | 12 ++++++------
 drivers/net/virtio/virtio_rxtx_simple_neon.c    | 12 ++++++------
 drivers/net/virtio/virtio_rxtx_simple_sse.c     | 12 ++++++------
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/net/virtio/virtio_rxtx_simple_altivec.c 
b/drivers/net/virtio/virtio_rxtx_simple_altivec.c
index 62e5100a48..1ffae234da 100644
--- a/drivers/net/virtio/virtio_rxtx_simple_altivec.c
+++ b/drivers/net/virtio/virtio_rxtx_simple_altivec.c
@@ -102,12 +102,6 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf 
**rx_pkts,
 
        rte_prefetch0(rused);
 
-       if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
-               virtio_rxq_rearm_vec(rxvq);
-               if (unlikely(virtqueue_kick_prepare(vq)))
-                       virtqueue_notify(vq);
-       }
-
        nb_total = nb_used;
        ref_rx_pkts = rx_pkts;
        for (nb_pkts_received = 0;
@@ -204,5 +198,11 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf 
**rx_pkts,
        for (nb_used = 0; nb_used < nb_pkts_received; nb_used++)
                virtio_update_packet_stats(&rxvq->stats, ref_rx_pkts[nb_used]);
 
+       if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
+               virtio_rxq_rearm_vec(rxvq);
+               if (unlikely(virtqueue_kick_prepare(vq)))
+                       virtqueue_notify(vq);
+       }
+
        return nb_pkts_received;
 }
diff --git a/drivers/net/virtio/virtio_rxtx_simple_neon.c 
b/drivers/net/virtio/virtio_rxtx_simple_neon.c
index c8e4b13a02..341dedce41 100644
--- a/drivers/net/virtio/virtio_rxtx_simple_neon.c
+++ b/drivers/net/virtio/virtio_rxtx_simple_neon.c
@@ -100,12 +100,6 @@ virtio_recv_pkts_vec(void *rx_queue,
 
        rte_prefetch_non_temporal(rused);
 
-       if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
-               virtio_rxq_rearm_vec(rxvq);
-               if (unlikely(virtqueue_kick_prepare(vq)))
-                       virtqueue_notify(vq);
-       }
-
        nb_total = nb_used;
        ref_rx_pkts = rx_pkts;
        for (nb_pkts_received = 0;
@@ -210,5 +204,11 @@ virtio_recv_pkts_vec(void *rx_queue,
        for (nb_used = 0; nb_used < nb_pkts_received; nb_used++)
                virtio_update_packet_stats(&rxvq->stats, ref_rx_pkts[nb_used]);
 
+       if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
+               virtio_rxq_rearm_vec(rxvq);
+               if (unlikely(virtqueue_kick_prepare(vq)))
+                       virtqueue_notify(vq);
+       }
+
        return nb_pkts_received;
 }
diff --git a/drivers/net/virtio/virtio_rxtx_simple_sse.c 
b/drivers/net/virtio/virtio_rxtx_simple_sse.c
index ff4eba33d6..2e17f9d1f2 100644
--- a/drivers/net/virtio/virtio_rxtx_simple_sse.c
+++ b/drivers/net/virtio/virtio_rxtx_simple_sse.c
@@ -100,12 +100,6 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf 
**rx_pkts,
 
        rte_prefetch0(rused);
 
-       if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
-               virtio_rxq_rearm_vec(rxvq);
-               if (unlikely(virtqueue_kick_prepare(vq)))
-                       virtqueue_notify(vq);
-       }
-
        nb_total = nb_used;
        ref_rx_pkts = rx_pkts;
        for (nb_pkts_received = 0;
@@ -194,5 +188,11 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf 
**rx_pkts,
        for (nb_used = 0; nb_used < nb_pkts_received; nb_used++)
                virtio_update_packet_stats(&rxvq->stats, ref_rx_pkts[nb_used]);
 
+       if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
+               virtio_rxq_rearm_vec(rxvq);
+               if (unlikely(virtqueue_kick_prepare(vq)))
+                       virtqueue_notify(vq);
+       }
+
        return nb_pkts_received;
 }
-- 
2.25.1