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

[Tiwei Bie <tiwei.bie@intel.com>]

On Wed, Sep 18, 2019 at 11:19:03AM +0800, Liu, Yong wrote:
> > -----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.

I mean below virtio_update_packet_stats() call in
virtio_xmit_pkts_inorder() should be removed while
doing above change:

https://github.com/DPDK/dpdk/blob/master/drivers/net/virtio/virtio_rxtx.c#L2201

I saw above line is removed by PATCH v2 2/2, but it
should be done in this patch.


> 
> 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
> > >