On Fri, Apr 16, 2021 at 10:18 AM Balazs Nemeth <bnem...@redhat.com> wrote:
>
> Move allocation out further and perform all allocation in bulk. The same
> goes for freeing packets. In the process, also rename
> virtio_dev_pktmbuf_alloc to virtio_dev_pktmbuf_prep. This
> function now receives an already allocated mbuf pointer.
>
> Signed-off-by: Balazs Nemeth <bnem...@redhat.com>
The title should indicate we are only touching the tx packed path.
What about tx split?
If it is too complex to rework, this can wait.
> ---
> lib/librte_vhost/virtio_net.c | 58 +++++++++++++++++++++++------------
> 1 file changed, 38 insertions(+), 20 deletions(-)
>
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index ff39878609..d6d5636e0f 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -2168,6 +2168,24 @@ virtio_dev_pktmbuf_alloc(struct virtio_net *dev,
> struct rte_mempool *mp,
> return NULL;
> }
>
> +static __rte_always_inline int
> +virtio_dev_pktmbuf_prep(struct virtio_net *dev, struct rte_mbuf *pkt,
> + uint32_t data_len)
> +{
> + if (rte_pktmbuf_tailroom(pkt) >= data_len)
> + return 0;
> +
> + /* attach an external buffer if supported */
> + if (dev->extbuf && !virtio_dev_extbuf_alloc(pkt, data_len))
> + return 0;
> +
> + /* check if chained buffers are allowed */
> + if (!dev->linearbuf)
> + return 0;
> +
> + return -1;
> +}
> +
If virtio_dev_pktmbuf_alloc() uses this new helper, we avoid
duplicating the logic.
> static __rte_noinline uint16_t
> virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
> struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
[snip]
> @@ -2429,7 +2440,7 @@ static __rte_always_inline int
> virtio_dev_tx_single_packed(struct virtio_net *dev,
> struct vhost_virtqueue *vq,
> struct rte_mempool *mbuf_pool,
> - struct rte_mbuf **pkts)
> + struct rte_mbuf *pkts)
> {
>
> uint16_t buf_id, desc_count = 0;
> @@ -2462,26 +2473,33 @@ virtio_dev_tx_packed(struct virtio_net *dev,
> uint32_t pkt_idx = 0;
> uint32_t remained = count;
>
> + if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts, count))
> + return 0;
> +
> do {
> rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
>
> if (remained >= PACKED_BATCH_SIZE) {
> - if (!virtio_dev_tx_batch_packed(dev, vq, mbuf_pool,
> + if (!virtio_dev_tx_batch_packed(dev, vq,
> &pkts[pkt_idx])) {
> pkt_idx += PACKED_BATCH_SIZE;
> remained -= PACKED_BATCH_SIZE;
> +
No need for the extra line.
> continue;
> }
> }
>
> if (virtio_dev_tx_single_packed(dev, vq, mbuf_pool,
> - &pkts[pkt_idx]))
> + pkts[pkt_idx]))
> break;
> pkt_idx++;
> remained--;
>
> } while (remained);
>
> + if (pkt_idx != count)
> + rte_pktmbuf_free_bulk(&pkts[pkt_idx], count - pkt_idx);
> +
> if (vq->shadow_used_idx) {
> do_data_copy_dequeue(vq);
>
With those comments addressed,
Reviewed-by: David Marchand <david.march...@redhat.com>
Thanks Balazs!
--
David Marchand
