[dpdk-dev] [PATCH v2 6/8] net/virtio: support IN_ORDER Rx and Tx
Maxime Coquelin
maxime.coquelin at redhat.com
Wed Jun 27 16:32:44 CEST 2018
On 06/27/2018 04:27 PM, Liu, Yong wrote:
>
>
>> -----Original Message-----
>> From: Maxime Coquelin [mailto:maxime.coquelin at redhat.com]
>> Sent: Wednesday, June 27, 2018 4:18 PM
>> To: Liu, Yong <yong.liu at intel.com>; Bie, Tiwei <tiwei.bie at intel.com>
>> Cc: Wang, Zhihong <zhihong.wang at intel.com>; dev at dpdk.org
>> Subject: Re: [PATCH v2 6/8] net/virtio: support IN_ORDER Rx and Tx
>>
>>
>>
>> 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."
>
> Thanks for point out this, Rx function choice was depended on merge-able feature. Will change comment in next release.
>
>>
>>> 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?
>
> My previous description may not clear, all Tx descriptors will be saved to avail ring in-order.
> For making code clean, packets which matched "can_push" option will be handled by simple xmit inorder function.
> Those packets can't match "can_push" will be handled one by one by previous xmit function.
Thanks! Sounds good with above clarification.
Maxime
> Thanks,
> Marvin
>
>>
>>> 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 at intel.com>
>>>
>>
>>
>> Other than above clarification needed, the code looks good to me.
>>
>> Thanks,
>> Maxime
More information about the dev
mailing list