Re: [net-next rfc v7 3/3] virtio-net: change the number of queues through ethtool

On Mon, 2012-12-03 at 13:25 +0200, Michael S. Tsirkin wrote:

On Mon, Dec 03, 2012 at 02:09:28PM +0800, Jason Wang wrote:

quoted

On Sunday, December 02, 2012 06:09:06 PM Michael S. Tsirkin wrote:

quoted

On Tue, Nov 27, 2012 at 06:16:00PM +0800, Jason Wang wrote:

quoted

This patch implement the {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 <redacted>
---

 drivers/net/virtio_net.c |   41 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index bcaa6e5..f08ec2a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -1578,10 +1578,51 @@ 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;

by the way shouldn't this be combined_count / 2?

And below channels->max_combined = vi->max_queue_pairs * 2; ?

[...]

In this ethtool API, 'channel' means an IRQ and set of queues that
trigger it.  So each ethtool-channel will correspond to one queue-pair
and not one virtio channel.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
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