From: Stephen Hemminger <stephen@networkplumber.org>
To: Yong Wang <yongwang@vmware.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3 1/4] vmxnet3: restore tx data ring support
Date: Tue, 5 Jan 2016 16:48:49 -0800 [thread overview]
Message-ID: <20160105164849.526442a8@xeon-e3> (raw)
In-Reply-To: <1452039178-15635-2-git-send-email-yongwang@vmware.com>
On Tue, 5 Jan 2016 16:12:55 -0800
Yong Wang <yongwang@vmware.com> wrote:
> @@ -365,6 +366,14 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
> break;
> }
>
> + if (rte_pktmbuf_pkt_len(txm) <= VMXNET3_HDR_COPY_SIZE) {
> + struct Vmxnet3_TxDataDesc *tdd;
> +
> + tdd = txq->data_ring.base + txq->cmd_ring.next2fill;
> + copy_size = rte_pktmbuf_pkt_len(txm);
> + rte_memcpy(tdd->data, rte_pktmbuf_mtod(txm, char *), copy_size);
> + }
Good idea to use a local region which optmizes the copy in the host,
but this implementation needs to be more general.
As written it is broken for multi-segment packets. A multi-segment
packet will have a pktlen >= datalen as in:
m -> mb_segs=3, pktlen=1200, datalen=200
-> datalen=900
-> datalen=100
There are two ways to fix this. You could test for nb_segs == 1
or better yet. Optimize each segment it might be that the first
segment (or tail segment) would fit in the available data area.
next prev parent reply other threads:[~2016-01-06 0:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-06 0:12 [dpdk-dev] [PATCH v3 0/4] vmxnet3 TSO and tx cksum offload Yong Wang
2016-01-06 0:12 ` [dpdk-dev] [PATCH v3 1/4] vmxnet3: restore tx data ring support Yong Wang
2016-01-06 0:48 ` Stephen Hemminger [this message]
2016-01-13 2:20 ` Yong Wang
2016-01-13 4:50 ` Stephen Hemminger
2016-01-06 0:12 ` [dpdk-dev] [PATCH v3 2/4] vmxnet3: add tx l4 cksum offload Yong Wang
2016-01-06 0:51 ` Stephen Hemminger
2016-01-13 2:20 ` Yong Wang
2016-01-06 0:12 ` [dpdk-dev] [PATCH v3 3/4] vmxnet3: add TSO support Yong Wang
2016-01-06 0:12 ` [dpdk-dev] [PATCH v3 4/4] vmxnet3: announce device offload capability Yong Wang
2016-01-06 0:52 ` Stephen Hemminger
2016-01-13 2:20 ` Yong Wang
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