Hi, Maxime: > -----Original Message----- > From: Maxime Coquelin [mailto:maxime.coque...@redhat.com] > Sent: Wednesday, March 1, 2017 5:44 PM > To: Yang, Zhiyong <zhiyong.y...@intel.com>; dev@dpdk.org > Cc: yuanhan....@linux.intel.com > Subject: Re: [PATCH 4/5] net/vhost: remove limit of vhost TX burst size > > > > On 02/24/2017 09:48 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....@linux.intel.com > > Cc: maxime.coque...@redhat.com > > > > Signed-off-by: Zhiyong Yang <zhiyong.y...@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; > > + } > > + } > It looks like the if/else could be avoided, but maybe you did so for > performance reason? > If this is the case, maybe you could add a comment or at least state this in > the > commit message.
Yes, you are right. if/else can be avoided and code will look more clean. I choose performance between them. Comments will be added in V2 here. Thanks Zhiyong > > Thanks, > Maxime > > > > r->stats.pkts += nb_tx; > > r->stats.missed_pkts += nb_bufs - nb_tx; > >
