Release notes for Neterion's (Formerly S2io) Xframe I/II PCI-X 10GbE driver. Contents ======= - 1. Introduction - 2. Identifying the adapter/interface - 3. Features supported - 4. Command line parameters - 5. Performance suggestions - 6. Available Downloads 1. Introduction: This Linux driver supports Neterion's Xframe I PCI-X 1.0 and Xframe II PCI-X 2.0 adapters. It supports several features such as jumbo frames, MSI/MSI-X, checksum offloads, TSO, UFO and so on. See below for complete list of features. All features are supported for both IPv4 and IPv6. 2. Identifying the adapter/interface: a. Insert the adapter(s) in your system. b. Build and load driver # insmod s2io.ko c. View log messages # dmesg | tail -40 You will see messages similar to: eth3: Neterion Xframe I 10GbE adapter (rev 3), Version 2.0.9.1, Intr type INTA eth4: Neterion Xframe II 10GbE adapter (rev 2), Version 2.0.9.1, Intr type INTA eth4: Device is on 64 bit 133MHz PCIX(M1) bus The above messages identify the adapter type(Xframe I/II), adapter revision, driver version, interface name(eth3, eth4), Interrupt type(INTA, MSI, MSI-X). In case of Xframe II, the PCI/PCI-X bus width and frequency are displayed as well. To associate an interface with a physical adapter use "ethtool -p <ethX>". The corresponding adapter's LED will blink multiple times. 3. Features supported: a. Jumbo frames. Xframe I/II supports MTU up to 9600 bytes, modifiable using ip command. b. Offloads. Supports checksum offload(TCP/UDP/IP) on transmit and receive, TSO. c. Multi-buffer receive mode. Scattering of packet across multiple buffers. Currently driver supports 2-buffer mode which yields significant performance improvement on certain platforms(SGI Altix, IBM xSeries). d. MSI/MSI-X. Can be enabled on platforms which support this feature (IA64, Xeon) resulting in noticeable performance improvement(up to 7% on certain platforms). e. Statistics. Comprehensive MAC-level and software statistics displayed using "ethtool -S" option. f. Multi-FIFO/Ring. Supports up to 8 transmit queues and receive rings, with multiple steering options. 4. Command line parameters a. tx_fifo_num Number of transmit queues Valid range: 1-8 Default: 1 b. rx_ring_num Number of receive rings Valid range: 1-8 Default: 1 c. tx_fifo_len Size of each transmit queue Valid range: Total length of all queues should not exceed 8192 Default: 4096 d. rx_ring_sz Size of each receive ring(in 4K blocks) Valid range: Limited by memory on system Default: 30 e. intr_type Specifies interrupt type. Possible values 0(INTA), 2(MSI-X) Valid values: 0, 2 Default: 2 5. Performance suggestions General: a. Set MTU to maximum(9000 for switch setup, 9600 in back-to-back configuration) b. Set TCP windows size to optimal value. For instance, for MTU=1500 a value of 210K has been observed to result in good performance. # sysctl -w net.ipv4.tcp_rmem="210000 210000 210000" # sysctl -w net.ipv4.tcp_wmem="210000 210000 210000" For MTU=9000, TCP window size of 10 MB is recommended. # sysctl -w net.ipv4.tcp_rmem="10000000 10000000 10000000" # sysctl -w net.ipv4.tcp_wmem="10000000 10000000 10000000" Transmit performance: a. By default, the driver respects BIOS settings for PCI bus parameters. However, you may want to experiment with PCI bus parameters max-split-transactions(MOST) and MMRBC (use setpci command). A MOST value of 2 has been found optimal for Opterons and 3 for Itanium. It could be different for your hardware. Set MMRBC to 4K**. For example you can set For opteron #setpci -d 17d5:* 62=1d For Itanium #setpci -d 17d5:* 62=3d For detailed description of the PCI registers, please see Xframe User Guide. b. Ensure Transmit Checksum offload is enabled. Use ethtool to set/verify this parameter. c. Turn on TSO(using "ethtool -K") # ethtool -K <ethX> tso on Receive performance: a. By default, the driver respects BIOS settings for PCI bus parameters. However, you may want to set PCI latency timer to 248. #setpci -d 17d5:* LATENCY_TIMER=f8 For detailed description of the PCI registers, please see Xframe User Guide. b. Use 2-buffer mode. This results in large performance boost on certain platforms(eg. SGI Altix, IBM xSeries). c. Ensure Receive Checksum offload is enabled. Use "ethtool -K ethX" command to set/verify this option. d. Enable NAPI feature(in kernel configuration Device Drivers ---> Network device support ---> Ethernet (10000 Mbit) ---> S2IO 10Gbe Xframe NIC) to bring down CPU utilization. ** For AMD opteron platforms with 8131 chipset, MMRBC=1 and MOST=1 are recommended as safe parameters. For more information, please review the AMD8131 errata at http://vip.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/ 26310_AMD-8131_HyperTransport_PCI-X_Tunnel_Revision_Guide_rev_3_18.pdf 6. Support For further support please contact either your 10GbE Xframe NIC vendor (IBM, HP, SGI etc.)