From e76097f8489a0c4c8044f3382ad81452c4771624 Mon Sep 17 00:00:00 2001 From: Marvin Liu Date: Thu, 19 Sep 2019 01:06:55 +0800 Subject: [PATCH] net/virtio: cleanup on demand when in-order Tx Check whether space are enough before burst enqueue operation. If more space is needed, will try to clean up used descriptors for space on demand. It can give more chances to free used descriptors, thus will help RFC2544 performance. Also deduct failed xmit packets from total xmit number. Fixes: e5f456a98d3c ("net/virtio: support in-order Rx and Tx") Cc: stable@dpdk.org Signed-off-by: Marvin Liu Reviewed-by: Maxime Coquelin --- drivers/net/virtio/virtio_rxtx.c | 62 +++++++++++++++++++++++--------- 1 file changed, 46 insertions(+), 16 deletions(-) diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c index 91df5b1d0c..e1c0e28b8b 100644 --- a/drivers/net/virtio/virtio_rxtx.c +++ b/drivers/net/virtio/virtio_rxtx.c @@ -2152,6 +2152,22 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts) return nb_tx; } +static __rte_always_inline int +virtio_xmit_try_cleanup_inorder(struct virtqueue *vq, uint16_t need) +{ + uint16_t nb_used, nb_clean, nb_descs; + struct virtio_hw *hw = vq->hw; + + nb_descs = vq->vq_free_cnt + need; + nb_used = VIRTQUEUE_NUSED(vq); + virtio_rmb(hw->weak_barriers); + nb_clean = RTE_MIN(need, (int)nb_used); + + virtio_xmit_cleanup_inorder(vq, nb_clean); + + return nb_descs - vq->vq_free_cnt; +} + uint16_t virtio_xmit_pkts_inorder(void *tx_queue, struct rte_mbuf **tx_pkts, @@ -2161,8 +2177,9 @@ virtio_xmit_pkts_inorder(void *tx_queue, struct virtqueue *vq = txvq->vq; struct virtio_hw *hw = vq->hw; uint16_t hdr_size = hw->vtnet_hdr_size; - uint16_t nb_used, nb_avail, nb_tx = 0, nb_inorder_pkts = 0; + uint16_t nb_used, nb_tx = 0, nb_inorder_pkts = 0; struct rte_mbuf *inorder_pkts[nb_pkts]; + int need; if (unlikely(hw->started == 0 && tx_pkts != hw->inject_pkts)) return nb_tx; @@ -2178,14 +2195,9 @@ virtio_xmit_pkts_inorder(void *tx_queue, if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh)) virtio_xmit_cleanup_inorder(vq, nb_used); - if (unlikely(!vq->vq_free_cnt)) - virtio_xmit_cleanup_inorder(vq, nb_used); - - nb_avail = RTE_MIN(vq->vq_free_cnt, nb_pkts); - - for (nb_tx = 0; nb_tx < nb_avail; nb_tx++) { + for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) { struct rte_mbuf *txm = tx_pkts[nb_tx]; - int slots, need; + int slots; /* optimize ring usage */ if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) || @@ -2203,6 +2215,17 @@ virtio_xmit_pkts_inorder(void *tx_queue, } if (nb_inorder_pkts) { + need = nb_inorder_pkts - vq->vq_free_cnt; + if (unlikely(need > 0)) { + need = virtio_xmit_try_cleanup_inorder(vq, + need); + if (unlikely(need > 0)) { + PMD_TX_LOG(ERR, + "No free tx descriptors to " + "transmit"); + break; + } + } virtqueue_enqueue_xmit_inorder(txvq, inorder_pkts, nb_inorder_pkts); nb_inorder_pkts = 0; @@ -2211,13 +2234,7 @@ virtio_xmit_pkts_inorder(void *tx_queue, slots = txm->nb_segs + 1; need = slots - vq->vq_free_cnt; if (unlikely(need > 0)) { - nb_used = VIRTQUEUE_NUSED(vq); - virtio_rmb(hw->weak_barriers); - need = RTE_MIN(need, (int)nb_used); - - virtio_xmit_cleanup_inorder(vq, need); - - need = slots - vq->vq_free_cnt; + need = virtio_xmit_try_cleanup_inorder(vq, slots); if (unlikely(need > 0)) { PMD_TX_LOG(ERR, @@ -2232,9 +2249,22 @@ virtio_xmit_pkts_inorder(void *tx_queue, } /* Transmit all inorder packets */ - if (nb_inorder_pkts) + if (nb_inorder_pkts) { + need = nb_inorder_pkts - vq->vq_free_cnt; + if (unlikely(need > 0)) { + need = virtio_xmit_try_cleanup_inorder(vq, + need); + if (unlikely(need > 0)) { + PMD_TX_LOG(ERR, + "No free tx descriptors to transmit"); + nb_inorder_pkts = vq->vq_free_cnt; + nb_tx -= need; + } + } + virtqueue_enqueue_xmit_inorder(txvq, inorder_pkts, nb_inorder_pkts); + } txvq->stats.packets += nb_tx; -- 2.20.1