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diff --git a/Documentation/networking/s2io.txt b/Documentation/networking/s2io.txt new file mode 100644 index 000000000..0362a42f7 --- /dev/null +++ b/Documentation/networking/s2io.txt @@ -0,0 +1,141 @@ +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.) |