On Fri, Aug 19, 2016 at 01:43:49AM -0400, Zhihong Wang wrote:
> This patch enables batch update of the used ring for better efficiency.
>
> Signed-off-by: Zhihong Wang <zhihong.wang at intel.com>
...
> diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
> index 1785695..87d09fa 100644
> --- a/lib/librte_vhost/virtio-net.c
> +++ b/lib/librte_vhost/virtio-net.c
> @@ -152,10 +152,14 @@ cleanup_device(struct virtio_net *dev, int destroy)
> static void
> free_device(struct virtio_net *dev)
> {
> + struct vhost_virtqueue *vq;
> uint32_t i;
>
> - for (i = 0; i < dev->virt_qp_nb; i++)
> - rte_free(dev->virtqueue[i * VIRTIO_QNUM]);
> + for (i = 0; i < dev->virt_qp_nb; i++) {
> + vq = dev->virtqueue[i * VIRTIO_QNUM];
> + rte_free(vq->shadow_used_ring);
> + rte_free(vq);
> + }
> rte_free(dev);
> }
> @@ -418,13 +422,18 @@ int
> vhost_set_vring_num(int vid, struct vhost_vring_state *state)
> {
> struct virtio_net *dev;
> + struct vhost_virtqueue *vq;
>
> dev = get_device(vid);
> if (dev == NULL)
> return -1;
>
> /* State->index refers to the queue index. The txq is 1, rxq is 0. */
> - dev->virtqueue[state->index]->size = state->num;
> + vq = dev->virtqueue[state->index];
> + vq->size = state->num;
> + vq->shadow_used_ring = rte_malloc("",
> + vq->size * sizeof(struct vring_used_elem),
> + RTE_CACHE_LINE_SIZE);
Few notes here:
- I think the typical way to not specific a string type is using NULL,
but not "".
- You should check the return value of rte_malloc: it could fail.
- Note that free_device() is invoked only when the vhost-user connection
is broken (say the guest is halt). However, vhost_set_vring_num() could
be invoked many times for a connection, say when you restart testpmd
many times. This would lead to memory leak.
The right way is to free it on get_vring_base().
--yliu
