Patchwork [net-next,3/3] virtio-net: change the number of queues through ethtool

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Submitter Jason Wang
Date Dec. 4, 2012, 11:07 a.m.
Message ID <1354619278-35702-4-git-send-email-jasowang@redhat.com>
Download mbox | patch
Permalink /patch/203608/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

Jason Wang - Dec. 4, 2012, 11:07 a.m.
This patch implement the ethtool_{set|get}_channels method of ethool to allow
user to change the number of queues dymaically when the device is running. This
would let the user to configure it on demand.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 44 insertions(+), 0 deletions(-)
Michael S. Tsirkin - Dec. 4, 2012, 1:49 p.m.
On Tue, Dec 04, 2012 at 07:07:58PM +0800, Jason Wang wrote:
> This patch implement the ethtool_{set|get}_channels method of ethool to allow
> user to change the number of queues dymaically when the device is running. This
> would let the user to configure it on demand.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/net/virtio_net.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 44 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 912f5b2..b9f9887 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1589,10 +1589,54 @@ static struct virtio_driver virtio_net_driver = {
>  #endif
>  };
>  
> +/* TODO: Eliminate OOO packets during switching */
> +static int virtnet_set_channels(struct net_device *dev,
> +				struct ethtool_channels *channels)
> +{
> +	struct virtnet_info *vi = netdev_priv(dev);
> +	u16 queue_pairs = channels->combined_count;
> +	u16 old_queue_pairs = vi->curr_queue_pairs;
> +
> +	/* We don't support separate rx/tx channels.
> +	 * We don't allow setting 'other' channels.
> +	 */
> +	if (channels->rx_count || channels->tx_count || channels->other_count)
> +		return -EINVAL;
> +
> +	if (queue_pairs > vi->max_queue_pairs)
> +		return -EINVAL;
> +
> +	vi->curr_queue_pairs = queue_pairs;
> +	if (virtnet_set_queues(vi) == 0) {
> +		netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
> +		netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);

Just use queue_pairs - it's shorter.

> +
> +		virtnet_set_affinity(vi, true);
> +	} else
> +		vi->curr_queue_pairs = old_queue_pairs;

Should be
	ret = virtnet_set_queues(vi);
	if (ret) {
		vi->curr_queue_pairs = old_queue_pairs;
		return ret;
	}
otherwise we loose error reporting.

Also it's better if virtnet_set_queues
gets queue_pairs as parameter and set curr_queue_pairs
on success.

> +
> +	return 0;
> +}
> +
> +static void virtnet_get_channels(struct net_device *dev,
> +				 struct ethtool_channels *channels)
> +{
> +	struct virtnet_info *vi = netdev_priv(dev);
> +
> +	channels->combined_count = vi->curr_queue_pairs;
> +	channels->max_combined = vi->max_queue_pairs;
> +	channels->max_other = 0;
> +	channels->rx_count = 0;
> +	channels->tx_count = 0;
> +	channels->other_count = 0;
> +}
> +
>  static const struct ethtool_ops virtnet_ethtool_ops = {
>  	.get_drvinfo = virtnet_get_drvinfo,
>  	.get_link = ethtool_op_get_link,
>  	.get_ringparam = virtnet_get_ringparam,
> +	.set_channels = virtnet_set_channels,
> +	.get_channels = virtnet_get_channels,
>  };
>  
>  static int __init init(void)
> -- 
> 1.7.1
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Jason Wang - Dec. 4, 2012, 2:46 p.m.
On Tuesday, December 04, 2012 03:49:59 PM Michael S. Tsirkin wrote:
> On Tue, Dec 04, 2012 at 07:07:58PM +0800, Jason Wang wrote:
> > This patch implement the ethtool_{set|get}_channels method of ethool to
> > allow user to change the number of queues dymaically when the device is
> > running. This would let the user to configure it on demand.
> > 
> > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > ---
> > 
> >  drivers/net/virtio_net.c |   44
> >  ++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 44
> >  insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 912f5b2..b9f9887 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -1589,10 +1589,54 @@ static struct virtio_driver virtio_net_driver = {
> > 
> >  #endif
> >  };
> > 
> > +/* TODO: Eliminate OOO packets during switching */
> > +static int virtnet_set_channels(struct net_device *dev,
> > +				struct ethtool_channels *channels)
> > +{
> > +	struct virtnet_info *vi = netdev_priv(dev);
> > +	u16 queue_pairs = channels->combined_count;
> > +	u16 old_queue_pairs = vi->curr_queue_pairs;
> > +
> > +	/* We don't support separate rx/tx channels.
> > +	 * We don't allow setting 'other' channels.
> > +	 */
> > +	if (channels->rx_count || channels->tx_count || channels->other_count)
> > +		return -EINVAL;
> > +
> > +	if (queue_pairs > vi->max_queue_pairs)
> > +		return -EINVAL;
> > +
> > +	vi->curr_queue_pairs = queue_pairs;
> > +	if (virtnet_set_queues(vi) == 0) {
> > +		netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
> > +		netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
> 
> Just use queue_pairs - it's shorter.

Ok.
> 
> > +
> > +		virtnet_set_affinity(vi, true);
> > +	} else
> > +		vi->curr_queue_pairs = old_queue_pairs;
> 
> Should be
> 	ret = virtnet_set_queues(vi);
> 	if (ret) {
> 		vi->curr_queue_pairs = old_queue_pairs;
> 		return ret;
> 	}
> otherwise we loose error reporting.
> 

Right.
> Also it's better if virtnet_set_queues
> gets queue_pairs as parameter and set curr_queue_pairs
> on success.

True, looks simpler than current method, will do it in next version.
> 
> > +
> > +	return 0;
> > +}
> > +
> > +static void virtnet_get_channels(struct net_device *dev,
> > +				 struct ethtool_channels *channels)
> > +{
> > +	struct virtnet_info *vi = netdev_priv(dev);
> > +
> > +	channels->combined_count = vi->curr_queue_pairs;
> > +	channels->max_combined = vi->max_queue_pairs;
> > +	channels->max_other = 0;
> > +	channels->rx_count = 0;
> > +	channels->tx_count = 0;
> > +	channels->other_count = 0;
> > +}
> > +
> > 
> >  static const struct ethtool_ops virtnet_ethtool_ops = {
> >  
> >  	.get_drvinfo = virtnet_get_drvinfo,
> >  	.get_link = ethtool_op_get_link,
> >  	.get_ringparam = virtnet_get_ringparam,
> > 
> > +	.set_channels = virtnet_set_channels,
> > +	.get_channels = virtnet_get_channels,
> > 
> >  };
> >  
> >  static int __init init(void)
> 
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Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 912f5b2..b9f9887 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1589,10 +1589,54 @@  static struct virtio_driver virtio_net_driver = {
 #endif
 };
 
+/* TODO: Eliminate OOO packets during switching */
+static int virtnet_set_channels(struct net_device *dev,
+				struct ethtool_channels *channels)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	u16 queue_pairs = channels->combined_count;
+	u16 old_queue_pairs = vi->curr_queue_pairs;
+
+	/* We don't support separate rx/tx channels.
+	 * We don't allow setting 'other' channels.
+	 */
+	if (channels->rx_count || channels->tx_count || channels->other_count)
+		return -EINVAL;
+
+	if (queue_pairs > vi->max_queue_pairs)
+		return -EINVAL;
+
+	vi->curr_queue_pairs = queue_pairs;
+	if (virtnet_set_queues(vi) == 0) {
+		netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
+		netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
+
+		virtnet_set_affinity(vi, true);
+	} else
+		vi->curr_queue_pairs = old_queue_pairs;
+
+	return 0;
+}
+
+static void virtnet_get_channels(struct net_device *dev,
+				 struct ethtool_channels *channels)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+
+	channels->combined_count = vi->curr_queue_pairs;
+	channels->max_combined = vi->max_queue_pairs;
+	channels->max_other = 0;
+	channels->rx_count = 0;
+	channels->tx_count = 0;
+	channels->other_count = 0;
+}
+
 static const struct ethtool_ops virtnet_ethtool_ops = {
 	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
 	.get_ringparam = virtnet_get_ringparam,
+	.set_channels = virtnet_set_channels,
+	.get_channels = virtnet_get_channels,
 };
 
 static int __init init(void)