Re: [dpdk-dev] [PATCH v2 6/8] net/virtio: support IN_ORDER Rx and Tx

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 06/25/2018 05:17 PM, Marvin Liu wrote:
> IN_ORDER Rx function can support merge-able feature. Descriptors
My understanding of the code is that IN_ORDER Rx function only supports
mergeable feature (and it seems to be confirmed by patch 7).

So maybe change the text to:
"IN_ORDER Rx function requires merge-able feature."

> 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 can't be
s/can support/supports/

> transmitted by IN_ORDER Tx will be handled by normal Tx.

Can you clarify why some packets can't be transmitted by IN_ORDER Tx?

> 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 with normal xmit
>              }
>      }
>      if (inorder burst list not empty) {
>              xmit inorder burst list
>      }
>      update_avail_ring()
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>
> 


Other than above clarification needed, the code looks good to me.

Thanks,
Maxime