Subject: Re: [RFC V7 PATCH 7/7] vhost_net: add interrupt coalescing support

From: Stephen Hemminger <[email-masked]>
Date: Tue, 26 May 2015 11:02:52 -0700

On Mon, 25 May 2015 01:24:04 -0400
Jason Wang <[email-masked]> wrote:

> Signed-off-by: Jason Wang <[email-masked]>
> ---
>  drivers/vhost/net.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 7d137a4..5ee28b7 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -320,6 +320,9 @@ static void handle_tx(struct vhost_net *net)
>  	hdr_size = nvq->vhost_hlen;
>  	zcopy = nvq->ubufs;
>  
> +	/* Finish pending interrupts first */
> +	vhost_check_coalesce_and_signal(vq->dev, vq, false);
> +
>  	for (;;) {
>  		/* Release DMAs done buffers first */
>  		if (zcopy)
> @@ -415,6 +418,7 @@ static void handle_tx(struct vhost_net *net)
>  		}
>  	}
>  out:
> +	vhost_check_coalesce_and_signal(vq->dev, vq, true);
>  	mutex_unlock(&vq->mutex);
>  }
>  
> @@ -554,6 +558,9 @@ static void handle_rx(struct vhost_net *net)
>  		vq->log : NULL;
>  	mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
>  
> +	/* Finish pending interrupts first */
> +	vhost_check_coalesce_and_signal(vq->dev, vq, false);
> +
>  	while ((sock_len = peek_head_len(sock->sk))) {
>  		sock_len += sock_hlen;
>  		vhost_len = sock_len + vhost_hlen;
> @@ -638,6 +645,7 @@ static void handle_rx(struct vhost_net *net)
>  		}
>  	}
>  out:
> +	vhost_check_coalesce_and_signal(vq->dev, vq, true);
>  	mutex_unlock(&vq->mutex);
>  }
>  

Could you implement ethtool control of these coalescing parameters?