From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Tiwei Bie <tiwei.bie@intel.com>
Cc: dev@dpdk.org, jfreimann@redhat.com, zhihong.wang@intel.com
Subject: Re: [dpdk-dev] [PATCH v2 3/3] net/virtio: improve batching in mergeable path
Date: Wed, 19 Dec 2018 13:01:10 +0100 [thread overview]
Message-ID: <a712e008-ddb1-8de9-160b-bdfabdc9bce6@redhat.com> (raw)
In-Reply-To: <20181219111818.GA3443@dpdk-tbie.sh.intel.com>
On 12/19/18 12:18 PM, Tiwei Bie wrote:
> On Tue, Dec 11, 2018 at 02:48:04PM +0100, Maxime Coquelin wrote:
>> This patch improves both descriptors dequeue and refill,
>> by using the same bathing strategy as done in in-order path.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>> drivers/net/virtio/virtio_rxtx.c | 237 ++++++++++++++++---------------
>> 1 file changed, 126 insertions(+), 111 deletions(-)
>>
>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
>> index ebe5c74b5..59bcac2f7 100644
>> --- a/drivers/net/virtio/virtio_rxtx.c
>> +++ b/drivers/net/virtio/virtio_rxtx.c
>> @@ -267,41 +267,42 @@ virtqueue_enqueue_refill_inorder(struct virtqueue *vq,
>> }
>>
>> static inline int
>> -virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
>> +virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf **cookie,
>> + uint16_t num)
>> {
>> struct vq_desc_extra *dxp;
>> struct virtio_hw *hw = vq->hw;
>> - struct vring_desc *start_dp;
>> - uint16_t needed = 1;
>> - uint16_t head_idx, idx;
>> + struct vring_desc *start_dp = vq->vq_ring.desc;
>> + uint16_t idx, i;
>>
>> if (unlikely(vq->vq_free_cnt == 0))
>> return -ENOSPC;
>> - if (unlikely(vq->vq_free_cnt < needed))
>> + if (unlikely(vq->vq_free_cnt < num))
>> return -EMSGSIZE;
>>
>> - head_idx = vq->vq_desc_head_idx;
>> - if (unlikely(head_idx >= vq->vq_nentries))
>> + if (unlikely(vq->vq_desc_head_idx >= vq->vq_nentries))
>> return -EFAULT;
>>
>> - idx = head_idx;
>> - dxp = &vq->vq_descx[idx];
>> - dxp->cookie = (void *)cookie;
>> - dxp->ndescs = needed;
>> + for (i = 0; i < num; i++) {
>> + idx = vq->vq_desc_head_idx;
>> + dxp = &vq->vq_descx[idx];
>> + dxp->cookie = (void *)cookie[i];
>> + dxp->ndescs = 1;
>>
>> - start_dp = vq->vq_ring.desc;
>> - start_dp[idx].addr =
>> - VIRTIO_MBUF_ADDR(cookie, vq) +
>> - RTE_PKTMBUF_HEADROOM - hw->vtnet_hdr_size;
>> - start_dp[idx].len =
>> - cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
>> - start_dp[idx].flags = VRING_DESC_F_WRITE;
>> - idx = start_dp[idx].next;
>> - vq->vq_desc_head_idx = idx;
>> - if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
>> - vq->vq_desc_tail_idx = idx;
>> - vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
>> - vq_update_avail_ring(vq, head_idx);
>> + start_dp[idx].addr =
>> + VIRTIO_MBUF_ADDR(cookie[i], vq) +
>> + RTE_PKTMBUF_HEADROOM - hw->vtnet_hdr_size;
>> + start_dp[idx].len =
>> + cookie[i]->buf_len - RTE_PKTMBUF_HEADROOM +
>> + hw->vtnet_hdr_size;
>> + start_dp[idx].flags = VRING_DESC_F_WRITE;
>> + vq->vq_desc_head_idx = start_dp[idx].next;
>> + if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
>> + vq->vq_desc_tail_idx = vq->vq_desc_head_idx;
>
> It's better to break the loop here. Or maybe move
> this check out of the loop.
Right, I vote for breaking, else we might get an out of bound access.
Thanks!
>> + vq_update_avail_ring(vq, idx);
>> + }
>> +
>> + vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - num);
>>
>> return 0;
>> }
> [...]
>
prev parent reply other threads:[~2018-12-19 12:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 13:48 [dpdk-dev] [PATCH v2 0/3] net/virtio: Rx paths improvements Maxime Coquelin
2018-12-11 13:48 ` [dpdk-dev] [PATCH v2 1/3] net/virtio: inline refill and offload helpers Maxime Coquelin
2018-12-19 9:25 ` Jens Freimann
2018-12-19 10:26 ` Gavin Hu (Arm Technology China)
2018-12-19 10:53 ` Jens Freimann
2018-12-19 12:04 ` Maxime Coquelin
2018-12-11 13:48 ` [dpdk-dev] [PATCH v2 2/3] net/virtio: add non-mergeable support to in-order path Maxime Coquelin
2018-12-19 11:27 ` Tiwei Bie
2018-12-11 13:48 ` [dpdk-dev] [PATCH v2 3/3] net/virtio: improve batching in mergeable path Maxime Coquelin
2018-12-19 9:47 ` Jens Freimann
2018-12-19 12:08 ` Maxime Coquelin
2018-12-19 11:18 ` Tiwei Bie
2018-12-19 12:01 ` Maxime Coquelin [this message]
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