virtio: optimize Tx enqueue

All the error checks in virtqueue_enqueue_xmit are already done
by the caller. Therefore they can be removed to improve performance.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Huawei Xie <huawei.xie@intel.com>
This commit is contained in:
Stephen Hemminger 2016-03-04 10:19:21 -08:00 committed by Thomas Monjalon
parent dd856dfcb9
commit 17cbf09fe1

View File

@ -208,7 +208,7 @@ virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
return 0;
}
static int
static inline void
virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie,
uint16_t needed, int use_indirect, int can_push)
{
@ -219,14 +219,7 @@ virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie,
uint16_t head_size = txvq->hw->vtnet_hdr_size;
unsigned long offs;
if (unlikely(txvq->vq_free_cnt == 0))
return -ENOSPC;
if (unlikely(txvq->vq_free_cnt < needed))
return -EMSGSIZE;
head_idx = txvq->vq_desc_head_idx;
if (unlikely(head_idx >= txvq->vq_nentries))
return -EFAULT;
idx = head_idx;
dxp = &txvq->vq_descx[idx];
dxp->cookie = (void *)cookie;
@ -288,8 +281,6 @@ virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie,
txvq->vq_desc_tail_idx = idx;
txvq->vq_free_cnt = (uint16_t)(txvq->vq_free_cnt - needed);
vq_update_avail_ring(txvq, head_idx);
return 0;
}
static inline struct rte_mbuf *
@ -934,17 +925,7 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
}
/* Enqueue Packet buffers */
error = virtqueue_enqueue_xmit(txvq, txm, slots,
use_indirect, can_push);
if (unlikely(error)) {
if (error == ENOSPC)
PMD_TX_LOG(ERR, "virtqueue_enqueue Free count = 0");
else if (error == EMSGSIZE)
PMD_TX_LOG(ERR, "virtqueue_enqueue Free count < 1");
else
PMD_TX_LOG(ERR, "virtqueue_enqueue error: %d", error);
break;
}
virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push);
txvq->bytes += txm->pkt_len;
virtio_update_packet_stats(txvq, txm);