Bus 005 Device 002: ID 0bda:8156 Realtek Semiconductor Corp. USB 10/100/1G/2.5G LANLinux only makes use of one xhci interrupter ring so it doesn't matter which CPU the interrupt is pinned to unless you have something else generating significant sources of hwirqs.
The result is consistently capped at ~1.7–1.8 Gbit/s. CPU usage is not the bottleneck, but all xhci-hcd IRQs remain pinned to CPU0 and IRQ affinity cannot be changed (I/O error). RPS gives only marginal improvement.
Please post a full lsusb -v for the adapter.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.20
bDeviceClass 0 [unknown]
bDeviceSubClass 0 [unknown]
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x0bda Realtek Semiconductor Corp.
idProduct 0x8156 USB 10/100/1G/2.5G LAN
bcdDevice 31.04
iManufacturer 1 Realtek
iProduct 2 USB 10/100/1G/2.5G LAN
iSerial 6 <redacted>
bNumConfigurations 3
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0039
bNumInterfaces 1
bConfigurationValue 1
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 256mA
Interface Descriptor:
bInterfaceClass 255 Vendor Specific Class
bNumEndpoints 3
Endpoint Descriptor:
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2 Bulk
wMaxPacketSize 0x0400
bMaxBurst 3
Endpoint Descriptor:
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2 Bulk
wMaxPacketSize 0x0400
bMaxBurst 3
Endpoint Descriptor:
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3 Interrupt
wMaxPacketSize 0x0002
bInterval 11
Configuration Descriptor:
bConfigurationValue 2
bNumInterfaces 2
Interface Descriptor:
bInterfaceClass 2 Communications
bInterfaceSubClass 13
CDC Ethernet:
wMaxSegmentSize 1518
Interface Descriptor:
bInterfaceClass 10 CDC Data
Configuration Descriptor:
bConfigurationValue 3
bNumInterfaces 2
Interface Descriptor:
bInterfaceClass 2 Communications
bInterfaceSubClass 6 Ethernet Networking
Interface Descriptor:
bInterfaceClass 10 CDC Data
Statistics: Posted by dogukansahil — Sat Jan 10, 2026 3:48 pm