Re: [dpdk-dev] [PATCH v2 1/2] net/virtio: update stats when in order xmit done

["Liu, Yong" <yong.liu@intel.com>]

> -----Original Message-----
> From: Bie, Tiwei
> Sent: Wednesday, September 18, 2019 10:35 AM
> To: Liu, Yong <yong.liu@intel.com>
> Cc: maxime.coquelin@redhat.com; dev@dpdk.org
> Subject: Re: [PATCH v2 1/2] net/virtio: update stats when in order xmit
> done
> 
> On Wed, Sep 11, 2019 at 12:14:45AM +0800, Marvin Liu wrote:
> > When doing xmit in-order enqueue, packets are buffered and then flushed
> > into avail ring. Buffered packets can be dropped due to insufficient
> > space. Moving stats update action just after successful avail ring
> > updates can guarantee correctness.
> >
> > Signed-off-by: Marvin Liu <yong.liu@intel.com>
> > ---
> >  drivers/net/virtio/virtio_rxtx.c | 87 ++++++++++++++++----------------
> >  1 file changed, 44 insertions(+), 43 deletions(-)
> >
> > diff --git a/drivers/net/virtio/virtio_rxtx.c
> b/drivers/net/virtio/virtio_rxtx.c
> > index 27ead19fb..d3ca36831 100644
> > --- a/drivers/net/virtio/virtio_rxtx.c
> > +++ b/drivers/net/virtio/virtio_rxtx.c
> > @@ -106,6 +106,48 @@ vq_ring_free_id_packed(struct virtqueue *vq,
> uint16_t id)
> >  	dxp->next = VQ_RING_DESC_CHAIN_END;
> >  }
> >
> > +static inline void
> > +virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf
> *mbuf)
> > +{
> > +	uint32_t s = mbuf->pkt_len;
> > +	struct rte_ether_addr *ea;
> > +
> > +	stats->bytes += s;
> > +
> > +	if (s == 64) {
> > +		stats->size_bins[1]++;
> > +	} else if (s > 64 && s < 1024) {
> > +		uint32_t bin;
> > +
> > +		/* count zeros, and offset into correct bin */
> > +		bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
> > +		stats->size_bins[bin]++;
> > +	} else {
> > +		if (s < 64)
> > +			stats->size_bins[0]++;
> > +		else if (s < 1519)
> > +			stats->size_bins[6]++;
> > +		else
> > +			stats->size_bins[7]++;
> > +	}
> > +
> > +	ea = rte_pktmbuf_mtod(mbuf, struct rte_ether_addr *);
> > +	if (rte_is_multicast_ether_addr(ea)) {
> > +		if (rte_is_broadcast_ether_addr(ea))
> > +			stats->broadcast++;
> > +		else
> > +			stats->multicast++;
> > +	}
> > +}
> > +
> > +static inline void
> > +virtio_rx_stats_updated(struct virtnet_rx *rxvq, struct rte_mbuf *m)
> > +{
> > +	VIRTIO_DUMP_PACKET(m, m->data_len);
> > +
> > +	virtio_update_packet_stats(&rxvq->stats, m);
> > +}
> > +
> >  static uint16_t
> >  virtqueue_dequeue_burst_rx_packed(struct virtqueue *vq,
> >  				  struct rte_mbuf **rx_pkts,
> > @@ -317,7 +359,7 @@ virtio_xmit_cleanup(struct virtqueue *vq, uint16_t
> num)
> >  }
> >
> >  /* Cleanup from completed inorder transmits. */
> > -static void
> > +static __rte_always_inline void
> >  virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num)
> >  {
> >  	uint16_t i, idx = vq->vq_used_cons_idx;
> > @@ -596,6 +638,7 @@ virtqueue_enqueue_xmit_inorder(struct virtnet_tx
> *txvq,
> >  		dxp = &vq->vq_descx[vq->vq_avail_idx & (vq->vq_nentries - 1)];
> >  		dxp->cookie = (void *)cookies[i];
> >  		dxp->ndescs = 1;
> > +		virtio_update_packet_stats(&txvq->stats, cookies[i]);
> 
> The virtio_update_packet_stats() call in virtio_xmit_pkts_inorder()
> should be removed.
> 

Hi Tiwei,
Function remained in virtio_xmit_pkts_inorder is for those packets not handled by burst enqueue function.
Statistic of packets which handled in burst in_order enqueue function is updated in inner loop.

Thanks,
Marvin

> 
> >
> >  		hdr = (struct virtio_net_hdr *)
> >  			rte_pktmbuf_prepend(cookies[i], head_size);
> > @@ -1083,48 +1126,6 @@ virtio_discard_rxbuf_inorder(struct virtqueue *vq,
> struct rte_mbuf *m)
> >  	}
> >  }
> >
> > -static inline void
> > -virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf
> *mbuf)
> > -{
> > -	uint32_t s = mbuf->pkt_len;
> > -	struct rte_ether_addr *ea;
> > -
> > -	stats->bytes += s;
> > -
> > -	if (s == 64) {
> > -		stats->size_bins[1]++;
> > -	} else if (s > 64 && s < 1024) {
> > -		uint32_t bin;
> > -
> > -		/* count zeros, and offset into correct bin */
> > -		bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
> > -		stats->size_bins[bin]++;
> > -	} else {
> > -		if (s < 64)
> > -			stats->size_bins[0]++;
> > -		else if (s < 1519)
> > -			stats->size_bins[6]++;
> > -		else
> > -			stats->size_bins[7]++;
> > -	}
> > -
> > -	ea = rte_pktmbuf_mtod(mbuf, struct rte_ether_addr *);
> > -	if (rte_is_multicast_ether_addr(ea)) {
> > -		if (rte_is_broadcast_ether_addr(ea))
> > -			stats->broadcast++;
> > -		else
> > -			stats->multicast++;
> > -	}
> > -}
> > -
> > -static inline void
> > -virtio_rx_stats_updated(struct virtnet_rx *rxvq, struct rte_mbuf *m)
> > -{
> > -	VIRTIO_DUMP_PACKET(m, m->data_len);
> > -
> > -	virtio_update_packet_stats(&rxvq->stats, m);
> > -}
> > -
> >  /* Optionally fill offload information in structure */
> >  static inline int
> >  virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
> > --
> > 2.17.1
> >