On 7/2/2018 2:56 PM, Marvin Liu wrote:
> IN_ORDER Rx function depends on merge-able feature. Descriptors
> allocation and free will be done in bulk.
>
> Virtio dequeue logic:
> dequeue_burst_rx(burst mbufs)
> for (each mbuf b) {
> if (b need merge) {
> merge remained mbufs
> add merged mbuf to return mbufs list
> } else {
> add mbuf to return mbufs list
> }
> }
> if (last mbuf c need merge) {
> dequeue_burst_rx(required mbufs)
> merge last mbuf c
> }
> refill_avail_ring_bulk()
> update_avail_ring()
> return mbufs list
>
> IN_ORDER Tx function can support offloading features. Packets which
> matched "can_push" option will be handled by simple xmit function. Those
> packets can't match "can_push" will be handled by original xmit function
> with in-order flag.
>
> Virtio enqueue logic:
> xmit_cleanup(used descs)
> for (each xmit mbuf b) {
> if (b can inorder xmit) {
> add mbuf b to inorder burst list
> continue
> } else {
> xmit inorder burst list
> xmit mbuf b by original function
> }
> }
> if (inorder burst list not empty) {
> xmit inorder burst list
> }
> update_avail_ring()
>
> Signed-off-by: Marvin Liu <yong....@intel.com>
> Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com>
<...>
> @@ -150,6 +188,83 @@ virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
> }
> }
>
> +/* Cleanup from completed inorder transmits. */
> +static void
> +virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num)
> +{
> + uint16_t i, used_idx, desc_idx, last_idx;
Getting following build error [1], from code it looks like false positive, but
to get rid of the build error would it be OK to set initial value to "desc_idx"?
[1]
.../dpdk/drivers/net/virtio/virtio_rxtx.c:195:24: error: ‘desc_idx’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]
uint16_t i, used_idx, desc_idx, last_idx;
^~~~~~~~
