USBNET: increase max rx/tx qlen for improving USB3 thoughtput
The default RX_QLEN()/TX_QLEN() didn't consider super speed
USB device, so only max 4 URBs are scheduled at the same time
for tx/rx, then USB3 NIC can't perform very well.
With this patch, both rx and tx thoughput are increased more than
100Mbps when doing iperf test on ax88179_178a USB 3.0 NIC.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index d74de07..e4811d7 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -355,6 +355,15 @@
dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
break;
+ case USB_SPEED_SUPER:
+ /*
+ * Not take default 5ms qlen for super speed HC to
+ * save memory, and iperf tests show 2.5ms qlen can
+ * work well
+ */
+ dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
+ dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
+ break;
default:
dev->rx_qlen = dev->tx_qlen = 4;
}