Alvaro Karsz
2022-Dec-21 12:06 UTC
[PATCH] virtio_net: send notification coalescing command only if value changed
Don't send a VIRTIO_NET_CTRL_NOTF_COAL_TX_SET or
VIRTIO_NET_CTRL_NOTF_COAL_RX_SET command if the coalescing parameters
haven't changed.
Signed-off-by: Alvaro Karsz <alvaro.karsz at solid-run.com>
---
drivers/net/virtio_net.c | 48 ++++++++++++++++++++++------------------
1 file changed, 27 insertions(+), 21 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7723b2a49d8..1d7118de62a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2760,31 +2760,37 @@ static int virtnet_send_notf_coal_cmds(struct
virtnet_info *vi,
struct virtio_net_ctrl_coal_tx coal_tx;
struct virtio_net_ctrl_coal_rx coal_rx;
- coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
- coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
- sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
-
- if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
- VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
- &sgs_tx))
- return -EINVAL;
+ if (ec->tx_coalesce_usecs != vi->tx_usecs ||
+ ec->tx_max_coalesced_frames != vi->tx_max_packets) {
+ coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
+ coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
+ sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
+
+ if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
+ VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
+ &sgs_tx))
+ return -EINVAL;
- /* Save parameters */
- vi->tx_usecs = ec->tx_coalesce_usecs;
- vi->tx_max_packets = ec->tx_max_coalesced_frames;
+ /* Save parameters */
+ vi->tx_usecs = ec->tx_coalesce_usecs;
+ vi->tx_max_packets = ec->tx_max_coalesced_frames;
+ }
- coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
- coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
- sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
+ if (ec->rx_coalesce_usecs != vi->rx_usecs ||
+ ec->rx_max_coalesced_frames != vi->rx_max_packets) {
+ coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
+ coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
+ sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
- if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
- VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
- &sgs_rx))
- return -EINVAL;
+ if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
+ VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
+ &sgs_rx))
+ return -EINVAL;
- /* Save parameters */
- vi->rx_usecs = ec->rx_coalesce_usecs;
- vi->rx_max_packets = ec->rx_max_coalesced_frames;
+ /* Save parameters */
+ vi->rx_usecs = ec->rx_coalesce_usecs;
+ vi->rx_max_packets = ec->rx_max_coalesced_frames;
+ }
return 0;
}
--
2.32.0
Michael S. Tsirkin
2022-Dec-21 12:33 UTC
[PATCH] virtio_net: send notification coalescing command only if value changed
On Wed, Dec 21, 2022 at 02:06:18PM +0200, Alvaro Karsz wrote:> Don't send a VIRTIO_NET_CTRL_NOTF_COAL_TX_SET or > VIRTIO_NET_CTRL_NOTF_COAL_RX_SET command if the coalescing parameters > haven't changed. > > Signed-off-by: Alvaro Karsz <alvaro.karsz at solid-run.com>Why do we bother? Resending needs more code and helps reliability ...> --- > drivers/net/virtio_net.c | 48 ++++++++++++++++++++++------------------ > 1 file changed, 27 insertions(+), 21 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 7723b2a49d8..1d7118de62a 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -2760,31 +2760,37 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi, > struct virtio_net_ctrl_coal_tx coal_tx; > struct virtio_net_ctrl_coal_rx coal_rx; > > - coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs); > - coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames); > - sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx)); > - > - if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, > - VIRTIO_NET_CTRL_NOTF_COAL_TX_SET, > - &sgs_tx)) > - return -EINVAL; > + if (ec->tx_coalesce_usecs != vi->tx_usecs || > + ec->tx_max_coalesced_frames != vi->tx_max_packets) { > + coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs); > + coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames); > + sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx)); > + > + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, > + VIRTIO_NET_CTRL_NOTF_COAL_TX_SET, > + &sgs_tx)) > + return -EINVAL; > > - /* Save parameters */ > - vi->tx_usecs = ec->tx_coalesce_usecs; > - vi->tx_max_packets = ec->tx_max_coalesced_frames; > + /* Save parameters */ > + vi->tx_usecs = ec->tx_coalesce_usecs; > + vi->tx_max_packets = ec->tx_max_coalesced_frames; > + } > > - coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs); > - coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames); > - sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx)); > + if (ec->rx_coalesce_usecs != vi->rx_usecs || > + ec->rx_max_coalesced_frames != vi->rx_max_packets) { > + coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs); > + coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames); > + sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx)); > > - if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, > - VIRTIO_NET_CTRL_NOTF_COAL_RX_SET, > - &sgs_rx)) > - return -EINVAL; > + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, > + VIRTIO_NET_CTRL_NOTF_COAL_RX_SET, > + &sgs_rx)) > + return -EINVAL; > > - /* Save parameters */ > - vi->rx_usecs = ec->rx_coalesce_usecs; > - vi->rx_max_packets = ec->rx_max_coalesced_frames; > + /* Save parameters */ > + vi->rx_usecs = ec->rx_coalesce_usecs; > + vi->rx_max_packets = ec->rx_max_coalesced_frames; > + } > > return 0; > } > -- > 2.32.0