From: Kevin Traynor <ktraynor@redhat.com>
To: Zhiyong Yang <zhiyong.yang@intel.com>, dev@dpdk.org
Cc: yuanhan.liu@linux.intel.com, maxime.coquelin@redhat.com
Subject: Re: [dpdk-dev] [PATCH 4/5] net/vhost: remove limit of vhost TX burst size
Date: Fri, 24 Feb 2017 11:08:56 +0000 [thread overview]
Message-ID: <22266556-4d0e-5db1-6a90-eebcecbe5283@redhat.com> (raw)
In-Reply-To: <1487926101-4637-5-git-send-email-zhiyong.yang@intel.com>
On 02/24/2017 08:48 AM, Zhiyong Yang wrote:
> vhost removes limit of TX burst size(32 pkts) and supports to make
> an best effort to transmit pkts.
>
> Cc: yuanhan.liu@linux.intel.com
> Cc: maxime.coquelin@redhat.com
>
> Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
> ---
> drivers/net/vhost/rte_eth_vhost.c | 24 ++++++++++++++++++++++--
> 1 file changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
> index e98cffd..1e1fa34 100644
> --- a/drivers/net/vhost/rte_eth_vhost.c
> +++ b/drivers/net/vhost/rte_eth_vhost.c
> @@ -52,6 +52,7 @@
> #define ETH_VHOST_QUEUES_ARG "queues"
> #define ETH_VHOST_CLIENT_ARG "client"
> #define ETH_VHOST_DEQUEUE_ZERO_COPY "dequeue-zero-copy"
> +#define VHOST_MAX_PKT_BURST 32
>
> static const char *valid_arguments[] = {
> ETH_VHOST_IFACE_ARG,
> @@ -434,8 +435,27 @@ eth_vhost_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
> goto out;
>
> /* Enqueue packets to guest RX queue */
> - nb_tx = rte_vhost_enqueue_burst(r->vid,
> - r->virtqueue_id, bufs, nb_bufs);
> + if (likely(nb_bufs <= VHOST_MAX_PKT_BURST))
> + nb_tx = rte_vhost_enqueue_burst(r->vid, r->virtqueue_id,
> + bufs, nb_bufs);
> + else {
> + uint16_t nb_send = nb_bufs;
> +
> + while (nb_send) {
> + uint16_t nb_pkts;
> + uint16_t num = (uint16_t)RTE_MIN(nb_send,
> + VHOST_MAX_PKT_BURST);
> +
> + nb_pkts = rte_vhost_enqueue_burst(r->vid,
> + r->virtqueue_id,
> + &bufs[nb_tx], num);
> +
> + nb_tx += nb_pkts;
> + nb_send -= nb_pkts;
> + if (nb_pkts < num)
> + break;
> + }
In the code above,
- if the VM does not service the queue, this will spin forever
- if the queue is almost full, it will be very slow
In the example of OVS, other ports being serviced by the same core would
stop being serviced or drop a lot of packets.
If you want to remove the 32 pkt limitation, the
rte_vhost_enqueue_burst() api limitation needs to be changed first. It
doesn't make sense to put retry code in eth_vhost_tx() fn, the
application can retry if it wants to.
> + }
>
> r->stats.pkts += nb_tx;
> r->stats.missed_pkts += nb_bufs - nb_tx;
>
next prev parent reply other threads:[~2017-02-24 11:08 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-24 8:48 [dpdk-dev] [PATCH 0/5] consistent PMD batching behaviour Zhiyong Yang
2017-02-24 8:48 ` [dpdk-dev] [PATCH 1/5] net/fm10k: remove limit of fm10k_xmit_pkts_vec burst size Zhiyong Yang
2017-02-24 9:32 ` Bruce Richardson
2017-02-24 9:36 ` Bruce Richardson
2017-02-24 9:48 ` Yang, Zhiyong
2017-03-03 11:17 ` [dpdk-dev] [PATCH v2 0/5] consistent PMD batching behaviour Zhiyong Yang
2017-03-03 11:17 ` [dpdk-dev] [PATCH v2 1/5] net/fm10k: remove limit of fm10k_xmit_pkts_vec burst size Zhiyong Yang
2017-03-29 7:16 ` [dpdk-dev] [PATCH v3 0/5] consistent PMD batching behaviour Zhiyong Yang
2017-03-29 7:16 ` [dpdk-dev] [PATCH v3 1/5] net/fm10k: remove limit of fm10k_xmit_pkts_vec burst size Zhiyong Yang
2017-03-29 7:16 ` [dpdk-dev] [PATCH v3 2/5] net/i40e: remove limit of i40e_xmit_pkts_vec " Zhiyong Yang
2017-03-29 7:16 ` [dpdk-dev] [PATCH v3 3/5] net/ixgbe: remove limit of ixgbe_xmit_pkts_vec " Zhiyong Yang
2017-03-29 7:16 ` [dpdk-dev] [PATCH v3 4/5] net/vhost: remove limit of vhost TX " Zhiyong Yang
2017-03-29 7:16 ` [dpdk-dev] [PATCH v3 5/5] net/vhost: remove limit of vhost RX " Zhiyong Yang
2017-03-30 12:54 ` [dpdk-dev] [PATCH v3 0/5] consistent PMD batching behaviour Ferruh Yigit
2017-03-31 7:00 ` Yao, Lei A
2017-03-03 11:17 ` [dpdk-dev] [PATCH v2 2/5] net/i40e: remove limit of i40e_xmit_pkts_vec burst size Zhiyong Yang
2017-03-24 14:03 ` Ferruh Yigit
2017-03-03 11:17 ` [dpdk-dev] [PATCH v2 3/5] net/ixgbe: remove limit of ixgbe_xmit_pkts_vec " Zhiyong Yang
2017-03-03 11:17 ` [dpdk-dev] [PATCH v2 4/5] net/vhost: remove limit of vhost TX " Zhiyong Yang
2017-03-03 11:17 ` [dpdk-dev] [PATCH v2 5/5] net/vhost: remove limit of vhost RX " Zhiyong Yang
2017-03-05 13:02 ` [dpdk-dev] [PATCH v2 0/5] consistent PMD batching behaviour Ananyev, Konstantin
2017-03-06 2:13 ` Yang, Zhiyong
2017-03-24 14:02 ` Ferruh Yigit
2017-03-25 6:29 ` Yang, Zhiyong
2017-03-28 10:00 ` Yang, Zhiyong
2017-03-28 10:05 ` Ferruh Yigit
2017-02-24 8:48 ` [dpdk-dev] [PATCH 2/5] net/i40e: remove limit of i40e_xmit_pkts_vec burst size Zhiyong Yang
2017-02-24 8:48 ` [dpdk-dev] [PATCH 3/5] net/ixgbe: remove limit of ixgbe_xmit_pkts_vec " Zhiyong Yang
2017-02-24 8:48 ` [dpdk-dev] [PATCH 4/5] net/vhost: remove limit of vhost TX " Zhiyong Yang
2017-02-24 11:08 ` Kevin Traynor [this message]
2017-02-24 13:04 ` Bruce Richardson
2017-02-24 13:33 ` Kevin Traynor
2017-03-01 9:44 ` Maxime Coquelin
2017-03-01 13:24 ` Yang, Zhiyong
2017-02-24 8:48 ` [dpdk-dev] [PATCH 5/5] net/vhost: remove limit of vhost RX " Zhiyong Yang
2017-02-24 11:41 ` Kevin Traynor
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