From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: "Xie, Huawei" <huawei.xie@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
"dev@dpdk.org" <dev@dpdk.org>,
Victor Kaplansky <vkaplans@redhat.com>
Subject: Re: [dpdk-dev] [PATCH v2 3/7] vhost: refactor virtio_dev_merge_rx
Date: Mon, 7 Mar 2016 16:38:45 +0800 [thread overview]
Message-ID: <20160307083845.GF14300@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <C37D651A908B024F974696C65296B57B4C6384E3@SHSMSX101.ccr.corp.intel.com>
On Mon, Mar 07, 2016 at 07:52:22AM +0000, Xie, Huawei wrote:
> On 2/18/2016 9:48 PM, Yuanhan Liu wrote:
> > Current virtio_dev_merge_rx() implementation just looks like the
> > old rte_vhost_dequeue_burst(), full of twisted logic, that you
> > can see same code block in quite many different places.
> >
> > However, the logic of virtio_dev_merge_rx() is quite similar to
> > virtio_dev_rx(). The big difference is that the mergeable one
> > could allocate more than one available entries to hold the data.
> > Fetching all available entries to vec_buf at once makes the
> [...]
> > - }
> > +static inline uint32_t __attribute__((always_inline))
> > +copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
> > + uint16_t res_start_idx, uint16_t res_end_idx,
> > + struct rte_mbuf *m)
> > +{
> > + struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
> > + uint32_t vec_idx = 0;
> > + uint16_t cur_idx = res_start_idx;
> > + uint64_t desc_addr;
> > + uint32_t mbuf_offset, mbuf_avail;
> > + uint32_t desc_offset, desc_avail;
> > + uint32_t cpy_len;
> > + uint16_t desc_idx, used_idx;
> > + uint32_t nr_used = 0;
> >
> > - cpy_len = RTE_MIN(vb_avail, seg_avail);
> > + if (m == NULL)
> > + return 0;
>
> Is this inherited from old code?
Yes.
> Let us remove the unnecessary check.
> Caller ensures it is not NULL.
...
> > + desc_avail = vq->buf_vec[vec_idx].buf_len - vq->vhost_hlen;
> > + desc_offset = vq->vhost_hlen;
>
> As we know we are in merge-able path, use sizeof(virtio_net_hdr) to save
> one load for the header len.
Please, it's a refactor patch series. You have mentioned quite many
trivial issues here and there, which I don't care too much and I don't
think they would matter somehow. In addition, they are actually from
the old code.
>
> > +
> > + mbuf_avail = rte_pktmbuf_data_len(m);
> > + mbuf_offset = 0;
> > + while (1) {
> > + /* done with current desc buf, get the next one */
> > +
> [...]
> > + if (reserve_avail_buf_mergeable(vq, pkt_len, &start, &end) < 0)
> > + break;
> >
> > + nr_used = copy_mbuf_to_desc_mergeable(dev, vq, start, end,
> > + pkts[pkt_idx]);
>
> In which case couldn't we get nr_used from start and end?
When pkts[pkt_idx] is NULL, though you suggest to remove it, the check
is here.
--yliu
next prev parent reply other threads:[~2016-03-07 8:36 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-03 6:06 [dpdk-dev] [PATCH 0/5 for 2.3] vhost rxtx refactor Yuanhan Liu
2015-12-03 6:06 ` [dpdk-dev] [PATCH 1/5] vhost: refactor rte_vhost_dequeue_burst Yuanhan Liu
2015-12-03 7:02 ` Stephen Hemminger
2015-12-03 7:25 ` Yuanhan Liu
2015-12-03 7:03 ` Stephen Hemminger
2015-12-12 6:55 ` Rich Lane
2015-12-14 1:55 ` Yuanhan Liu
2016-01-26 10:30 ` Xie, Huawei
2016-01-27 3:26 ` Yuanhan Liu
2016-01-27 6:12 ` Xie, Huawei
2016-01-27 6:16 ` Yuanhan Liu
2015-12-03 6:06 ` [dpdk-dev] [PATCH 2/5] vhost: refactor virtio_dev_rx Yuanhan Liu
2015-12-11 20:42 ` Rich Lane
2015-12-14 1:47 ` Yuanhan Liu
2016-01-21 13:50 ` Jérôme Jutteau
2016-01-27 3:27 ` Yuanhan Liu
2015-12-03 6:06 ` [dpdk-dev] [PATCH 3/5] vhost: refactor virtio_dev_merge_rx Yuanhan Liu
2015-12-03 6:06 ` [dpdk-dev] [PATCH 4/5] vhost: do not use rte_memcpy for virtio_hdr copy Yuanhan Liu
2016-01-27 2:46 ` Xie, Huawei
2016-01-27 3:22 ` Yuanhan Liu
2016-01-27 5:56 ` Xie, Huawei
2016-01-27 6:02 ` Yuanhan Liu
2016-01-27 6:16 ` Xie, Huawei
2016-01-27 6:35 ` Yuanhan Liu
2015-12-03 6:06 ` [dpdk-dev] [PATCH 5/5] vhost: don't use unlikely for VIRTIO_NET_F_MRG_RXBUF detection Yuanhan Liu
2016-02-17 22:50 ` [dpdk-dev] [PATCH 0/5 for 2.3] vhost rxtx refactor Thomas Monjalon
2016-02-18 4:09 ` Yuanhan Liu
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 0/7] " Yuanhan Liu
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 1/7] vhost: refactor rte_vhost_dequeue_burst Yuanhan Liu
2016-03-03 16:21 ` Xie, Huawei
2016-03-04 2:21 ` Yuanhan Liu
2016-03-07 2:19 ` Xie, Huawei
2016-03-07 2:44 ` Yuanhan Liu
2016-03-03 16:30 ` Xie, Huawei
2016-03-04 2:17 ` Yuanhan Liu
2016-03-07 2:32 ` Xie, Huawei
2016-03-07 2:48 ` Yuanhan Liu
2016-03-07 2:59 ` Xie, Huawei
2016-03-07 6:14 ` Yuanhan Liu
2016-03-03 17:19 ` Xie, Huawei
2016-03-04 2:11 ` Yuanhan Liu
2016-03-07 2:55 ` Xie, Huawei
2016-03-03 17:40 ` Xie, Huawei
2016-03-04 2:32 ` Yuanhan Liu
2016-03-07 3:02 ` Xie, Huawei
2016-03-07 3:03 ` Xie, Huawei
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 2/7] vhost: refactor virtio_dev_rx Yuanhan Liu
2016-03-07 3:34 ` Xie, Huawei
2016-03-08 12:27 ` Yuanhan Liu
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 3/7] vhost: refactor virtio_dev_merge_rx Yuanhan Liu
2016-03-07 6:22 ` Xie, Huawei
2016-03-07 6:36 ` Yuanhan Liu
2016-03-07 6:38 ` Xie, Huawei
2016-03-07 6:51 ` Yuanhan Liu
2016-03-07 7:03 ` Xie, Huawei
2016-03-07 7:16 ` Xie, Huawei
2016-03-07 8:20 ` Yuanhan Liu
2016-03-07 7:52 ` Xie, Huawei
2016-03-07 8:38 ` Yuanhan Liu [this message]
2016-03-07 9:27 ` Xie, Huawei
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 4/7] vhost: do not use rte_memcpy for virtio_hdr copy Yuanhan Liu
2016-03-07 1:20 ` Xie, Huawei
2016-03-07 4:20 ` Stephen Hemminger
2016-03-07 5:24 ` Xie, Huawei
2016-03-07 6:21 ` Yuanhan Liu
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 5/7] vhost: don't use unlikely for VIRTIO_NET_F_MRG_RXBUF detection Yuanhan Liu
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 6/7] vhost: do sanity check for desc->len Yuanhan Liu
2016-02-18 13:49 ` [dpdk-dev] [PATCH v2 7/7] vhost: do sanity check for desc->next Yuanhan Liu
2016-03-07 3:10 ` Xie, Huawei
2016-03-07 6:57 ` Yuanhan Liu
2016-02-29 16:06 ` [dpdk-dev] [PATCH v2 0/7] vhost rxtx refactor Thomas Monjalon
2016-03-01 6:01 ` Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 0/8] vhost rxtx refactor and fixes Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 1/8] vhost: refactor rte_vhost_dequeue_burst Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 2/8] vhost: refactor virtio_dev_rx Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 3/8] vhost: refactor virtio_dev_merge_rx Yuanhan Liu
2016-03-11 16:18 ` Thomas Monjalon
2016-03-14 7:35 ` [dpdk-dev] [PATCH v4 " Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 4/8] vhost: do not use rte_memcpy for virtio_hdr copy Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 5/8] vhost: don't use unlikely for VIRTIO_NET_F_MRG_RXBUF detection Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 6/8] vhost: do sanity check for desc->len Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 7/8] vhost: do sanity check for desc->next against with vq->size Yuanhan Liu
2016-03-10 4:32 ` [dpdk-dev] [PATCH v3 8/8] vhost: avoid dead loop chain Yuanhan Liu
2016-03-14 23:09 ` [dpdk-dev] [PATCH v3 0/8] vhost rxtx refactor and fixes Thomas Monjalon
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