On Fri, Jun 08, 2012 at 11:35:25AM +0800, Jason Wang wrote: > >>> @@ -655,7 +695,17 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, > >>> struct net_device *dev) > >>> kfree_skb(skb); > >>> return NETDEV_TX_OK; > >>> } > >>> - virtqueue_kick(vi->svq); > >>> + > >>> + kick = virtqueue_kick_prepare(vi->svq); > >>> + if (unlikely(kick)) > >>> + virtqueue_notify(vi->svq); > >>> + > >>> + u64_stats_update_begin(&stats->syncp); > >>> + if (unlikely(kick)) > >>> + stats->data[VIRTNET_TX_KICKS]++; > >>> + stats->data[VIRTNET_TX_Q_BYTES] += skb->len; > >>> + stats->data[VIRTNET_TX_Q_PACKETS]++; > >is this statistic interesting? > >how about decrementing when we free? > >this way we see how many are pending.. > > > > Currently we didn't have per-vq statistics but per-cpu, so the skb > could be sent by one vcpu and freed by another. > Pehaps another reason to use per-queue satistics.
Just to stress these things do not need to contradict: you can have per cpu stats for each queue. -- MST _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
