Re: [rfc net-next v6 3/3] virtio-net: change the number of queues through ethtool
On 11/05/2012 07:46 AM, Rusty Russell wrote:
Jason Wang jasow...@redhat.com writes:
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 tune the device for specific applications.
...
+ /* Only two modes were support currently */
+ if (queue_pairs == 0)
+ return -EINVAL;
+ if (queue_pairs != vi-total_queue_pairs - 1 queue_pairs != 1)
+ return -EINVAL;
OK, so you let them do all or nothing, but this three-way test is
pretty unclear.
True, looks like the first check could be removed.
In fact, the whole total_queue_pairs/num_queue_pairs thing is weird (and
uncommented). I think for total you mean max; the maximum possible
queue pair number.
Yes, total means max, will add a comment or change the name to
max_queue_pairs/current_queue_pairs.
Let me go back and review the previous patch again...
Cheers,
Rusty.
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Re: [rfc net-next v6 3/3] virtio-net: change the number of queues through ethtool
On Tue, 2012-10-30 at 18:03 +0800, Jason Wang wrote:
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 tune the device for specific applications.
Signed-off-by: Jason Wang jasow...@redhat.com
---
drivers/net/virtio_net.c | 43 +++
1 files changed, 43 insertions(+), 0 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 8cc43e5..66fc129 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1616,10 +1616,53 @@ 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;
+
+ /* Only two modes were support currently */
+ if (queue_pairs == 0)
+ return -EINVAL;
+ if (queue_pairs != vi-total_queue_pairs - 1 queue_pairs != 1)
+ return -EINVAL;
You should also check that all of the other counts are == 0.
+ vi-num_queue_pairs = queue_pairs 1 ? queue_pairs + 1 : 1;
This doesn't make sense. You're setting vi-num_queue_pairs to be
combined_count + 1...
+ BUG_ON(virtnet_set_queues(vi));
+
+ netif_set_real_num_tx_queues(dev, vi-num_queue_pairs);
+ netif_set_real_num_rx_queues(dev, vi-num_queue_pairs);
+
+ return 0;
+}
+
+static void virtnet_get_channels(struct net_device *dev,
+ struct ethtool_channels *channels)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+
+ if (vi-total_queue_pairs != 1) {
+ channels-combined_count = vi-num_queue_pairs;
but here you report combined_count as being vi-num_queue_pairs. Do you
need to subtract 1 here?
Ben.
+ channels-max_combined = vi-total_queue_pairs - 1;
+ } else {
+ channels-combined_count = 1;
+ channels-max_combined = 1;
+ }
+
+ 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)
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
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Re: [rfc net-next v6 3/3] virtio-net: change the number of queues through ethtool
Jason Wang jasow...@redhat.com writes:
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 tune the device for specific applications.
...
+ /* Only two modes were support currently */
+ if (queue_pairs == 0)
+ return -EINVAL;
+ if (queue_pairs != vi-total_queue_pairs - 1 queue_pairs != 1)
+ return -EINVAL;
OK, so you let them do all or nothing, but this three-way test is
pretty unclear.
In fact, the whole total_queue_pairs/num_queue_pairs thing is weird (and
uncommented). I think for total you mean max; the maximum possible
queue pair number.
Let me go back and review the previous patch again...
Cheers,
Rusty.
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[rfc net-next v6 3/3] virtio-net: change the number of queues through ethtool
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 tune the device for specific applications.
Signed-off-by: Jason Wang jasow...@redhat.com
---
drivers/net/virtio_net.c | 43 +++
1 files changed, 43 insertions(+), 0 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 8cc43e5..66fc129 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1616,10 +1616,53 @@ 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;
+
+ /* Only two modes were support currently */
+ if (queue_pairs == 0)
+ return -EINVAL;
+ if (queue_pairs != vi-total_queue_pairs - 1 queue_pairs != 1)
+ return -EINVAL;
+
+ vi-num_queue_pairs = queue_pairs 1 ? queue_pairs + 1 : 1;
+ BUG_ON(virtnet_set_queues(vi));
+
+ netif_set_real_num_tx_queues(dev, vi-num_queue_pairs);
+ netif_set_real_num_rx_queues(dev, vi-num_queue_pairs);
+
+ return 0;
+}
+
+static void virtnet_get_channels(struct net_device *dev,
+struct ethtool_channels *channels)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+
+ if (vi-total_queue_pairs != 1) {
+ channels-combined_count = vi-num_queue_pairs;
+ channels-max_combined = vi-total_queue_pairs - 1;
+ } else {
+ channels-combined_count = 1;
+ channels-max_combined = 1;
+ }
+
+ 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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