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| 1 | Linux* Driver for Intel(R) Network Connection | ||
| 2 | =============================================================== | ||
| 3 | |||
| 4 | Intel Gigabit Linux driver. | ||
| 5 | Copyright(c) 1999 - 2010 Intel Corporation. | ||
| 6 | |||
| 7 | Contents | ||
| 8 | ======== | ||
| 9 | |||
| 10 | - Identifying Your Adapter | ||
| 11 | - Command Line Parameters | ||
| 12 | - Additional Configurations | ||
| 13 | - Support | ||
| 14 | |||
| 15 | Identifying Your Adapter | ||
| 16 | ======================== | ||
| 17 | |||
| 18 | The e1000e driver supports all PCI Express Intel(R) Gigabit Network | ||
| 19 | Connections, except those that are 82575, 82576 and 82580-based*. | ||
| 20 | |||
| 21 | * NOTE: The Intel(R) PRO/1000 P Dual Port Server Adapter is supported by | ||
| 22 | the e1000 driver, not the e1000e driver due to the 82546 part being used | ||
| 23 | behind a PCI Express bridge. | ||
| 24 | |||
| 25 | For more information on how to identify your adapter, go to the Adapter & | ||
| 26 | Driver ID Guide at: | ||
| 27 | |||
| 28 | http://support.intel.com/support/go/network/adapter/idguide.htm | ||
| 29 | |||
| 30 | For the latest Intel network drivers for Linux, refer to the following | ||
| 31 | website. In the search field, enter your adapter name or type, or use the | ||
| 32 | networking link on the left to search for your adapter: | ||
| 33 | |||
| 34 | http://support.intel.com/support/go/network/adapter/home.htm | ||
| 35 | |||
| 36 | Command Line Parameters | ||
| 37 | ======================= | ||
| 38 | |||
| 39 | The default value for each parameter is generally the recommended setting, | ||
| 40 | unless otherwise noted. | ||
| 41 | |||
| 42 | NOTES: For more information about the InterruptThrottleRate, | ||
| 43 | RxIntDelay, TxIntDelay, RxAbsIntDelay, and TxAbsIntDelay | ||
| 44 | parameters, see the application note at: | ||
| 45 | http://www.intel.com/design/network/applnots/ap450.htm | ||
| 46 | |||
| 47 | InterruptThrottleRate | ||
| 48 | --------------------- | ||
| 49 | Valid Range: 0,1,3,4,100-100000 (0=off, 1=dynamic, 3=dynamic conservative, | ||
| 50 | 4=simplified balancing) | ||
| 51 | Default Value: 3 | ||
| 52 | |||
| 53 | The driver can limit the amount of interrupts per second that the adapter | ||
| 54 | will generate for incoming packets. It does this by writing a value to the | ||
| 55 | adapter that is based on the maximum amount of interrupts that the adapter | ||
| 56 | will generate per second. | ||
| 57 | |||
| 58 | Setting InterruptThrottleRate to a value greater or equal to 100 | ||
| 59 | will program the adapter to send out a maximum of that many interrupts | ||
| 60 | per second, even if more packets have come in. This reduces interrupt | ||
| 61 | load on the system and can lower CPU utilization under heavy load, | ||
| 62 | but will increase latency as packets are not processed as quickly. | ||
| 63 | |||
| 64 | The driver has two adaptive modes (setting 1 or 3) in which | ||
| 65 | it dynamically adjusts the InterruptThrottleRate value based on the traffic | ||
| 66 | that it receives. After determining the type of incoming traffic in the last | ||
| 67 | timeframe, it will adjust the InterruptThrottleRate to an appropriate value | ||
| 68 | for that traffic. | ||
| 69 | |||
| 70 | The algorithm classifies the incoming traffic every interval into | ||
| 71 | classes. Once the class is determined, the InterruptThrottleRate value is | ||
| 72 | adjusted to suit that traffic type the best. There are three classes defined: | ||
| 73 | "Bulk traffic", for large amounts of packets of normal size; "Low latency", | ||
| 74 | for small amounts of traffic and/or a significant percentage of small | ||
| 75 | packets; and "Lowest latency", for almost completely small packets or | ||
| 76 | minimal traffic. | ||
| 77 | |||
| 78 | In dynamic conservative mode, the InterruptThrottleRate value is set to 4000 | ||
| 79 | for traffic that falls in class "Bulk traffic". If traffic falls in the "Low | ||
| 80 | latency" or "Lowest latency" class, the InterruptThrottleRate is increased | ||
| 81 | stepwise to 20000. This default mode is suitable for most applications. | ||
| 82 | |||
| 83 | For situations where low latency is vital such as cluster or | ||
| 84 | grid computing, the algorithm can reduce latency even more when | ||
| 85 | InterruptThrottleRate is set to mode 1. In this mode, which operates | ||
| 86 | the same as mode 3, the InterruptThrottleRate will be increased stepwise to | ||
| 87 | 70000 for traffic in class "Lowest latency". | ||
| 88 | |||
| 89 | In simplified mode the interrupt rate is based on the ratio of Tx and | ||
| 90 | Rx traffic. If the bytes per second rate is approximately equal the | ||
| 91 | interrupt rate will drop as low as 2000 interrupts per second. If the | ||
| 92 | traffic is mostly transmit or mostly receive, the interrupt rate could | ||
| 93 | be as high as 8000. | ||
| 94 | |||
| 95 | Setting InterruptThrottleRate to 0 turns off any interrupt moderation | ||
| 96 | and may improve small packet latency, but is generally not suitable | ||
| 97 | for bulk throughput traffic. | ||
| 98 | |||
| 99 | NOTE: InterruptThrottleRate takes precedence over the TxAbsIntDelay and | ||
| 100 | RxAbsIntDelay parameters. In other words, minimizing the receive | ||
| 101 | and/or transmit absolute delays does not force the controller to | ||
| 102 | generate more interrupts than what the Interrupt Throttle Rate | ||
| 103 | allows. | ||
| 104 | |||
| 105 | NOTE: When e1000e is loaded with default settings and multiple adapters | ||
| 106 | are in use simultaneously, the CPU utilization may increase non- | ||
| 107 | linearly. In order to limit the CPU utilization without impacting | ||
| 108 | the overall throughput, we recommend that you load the driver as | ||
| 109 | follows: | ||
| 110 | |||
| 111 | modprobe e1000e InterruptThrottleRate=3000,3000,3000 | ||
| 112 | |||
| 113 | This sets the InterruptThrottleRate to 3000 interrupts/sec for | ||
| 114 | the first, second, and third instances of the driver. The range | ||
| 115 | of 2000 to 3000 interrupts per second works on a majority of | ||
| 116 | systems and is a good starting point, but the optimal value will | ||
| 117 | be platform-specific. If CPU utilization is not a concern, use | ||
| 118 | RX_POLLING (NAPI) and default driver settings. | ||
| 119 | |||
| 120 | RxIntDelay | ||
| 121 | ---------- | ||
| 122 | Valid Range: 0-65535 (0=off) | ||
| 123 | Default Value: 0 | ||
| 124 | |||
| 125 | This value delays the generation of receive interrupts in units of 1.024 | ||
| 126 | microseconds. Receive interrupt reduction can improve CPU efficiency if | ||
| 127 | properly tuned for specific network traffic. Increasing this value adds | ||
| 128 | extra latency to frame reception and can end up decreasing the throughput | ||
| 129 | of TCP traffic. If the system is reporting dropped receives, this value | ||
| 130 | may be set too high, causing the driver to run out of available receive | ||
| 131 | descriptors. | ||
| 132 | |||
| 133 | CAUTION: When setting RxIntDelay to a value other than 0, adapters may | ||
| 134 | hang (stop transmitting) under certain network conditions. If | ||
| 135 | this occurs a NETDEV WATCHDOG message is logged in the system | ||
| 136 | event log. In addition, the controller is automatically reset, | ||
| 137 | restoring the network connection. To eliminate the potential | ||
| 138 | for the hang ensure that RxIntDelay is set to 0. | ||
| 139 | |||
| 140 | RxAbsIntDelay | ||
| 141 | ------------- | ||
| 142 | Valid Range: 0-65535 (0=off) | ||
| 143 | Default Value: 8 | ||
| 144 | |||
| 145 | This value, in units of 1.024 microseconds, limits the delay in which a | ||
| 146 | receive interrupt is generated. Useful only if RxIntDelay is non-zero, | ||
| 147 | this value ensures that an interrupt is generated after the initial | ||
| 148 | packet is received within the set amount of time. Proper tuning, | ||
| 149 | along with RxIntDelay, may improve traffic throughput in specific network | ||
| 150 | conditions. | ||
| 151 | |||
| 152 | TxIntDelay | ||
| 153 | ---------- | ||
| 154 | Valid Range: 0-65535 (0=off) | ||
| 155 | Default Value: 8 | ||
| 156 | |||
| 157 | This value delays the generation of transmit interrupts in units of | ||
| 158 | 1.024 microseconds. Transmit interrupt reduction can improve CPU | ||
| 159 | efficiency if properly tuned for specific network traffic. If the | ||
| 160 | system is reporting dropped transmits, this value may be set too high | ||
| 161 | causing the driver to run out of available transmit descriptors. | ||
| 162 | |||
| 163 | TxAbsIntDelay | ||
| 164 | ------------- | ||
| 165 | Valid Range: 0-65535 (0=off) | ||
| 166 | Default Value: 32 | ||
| 167 | |||
| 168 | This value, in units of 1.024 microseconds, limits the delay in which a | ||
| 169 | transmit interrupt is generated. Useful only if TxIntDelay is non-zero, | ||
| 170 | this value ensures that an interrupt is generated after the initial | ||
| 171 | packet is sent on the wire within the set amount of time. Proper tuning, | ||
| 172 | along with TxIntDelay, may improve traffic throughput in specific | ||
| 173 | network conditions. | ||
| 174 | |||
| 175 | Copybreak | ||
| 176 | --------- | ||
| 177 | Valid Range: 0-xxxxxxx (0=off) | ||
| 178 | Default Value: 256 | ||
| 179 | |||
| 180 | Driver copies all packets below or equaling this size to a fresh Rx | ||
| 181 | buffer before handing it up the stack. | ||
| 182 | |||
| 183 | This parameter is different than other parameters, in that it is a | ||
| 184 | single (not 1,1,1 etc.) parameter applied to all driver instances and | ||
| 185 | it is also available during runtime at | ||
| 186 | /sys/module/e1000e/parameters/copybreak | ||
| 187 | |||
| 188 | SmartPowerDownEnable | ||
| 189 | -------------------- | ||
| 190 | Valid Range: 0-1 | ||
| 191 | Default Value: 0 (disabled) | ||
| 192 | |||
| 193 | Allows PHY to turn off in lower power states. The user can set this parameter | ||
| 194 | in supported chipsets. | ||
| 195 | |||
| 196 | KumeranLockLoss | ||
| 197 | --------------- | ||
| 198 | Valid Range: 0-1 | ||
| 199 | Default Value: 1 (enabled) | ||
| 200 | |||
| 201 | This workaround skips resetting the PHY at shutdown for the initial | ||
| 202 | silicon releases of ICH8 systems. | ||
| 203 | |||
| 204 | IntMode | ||
| 205 | ------- | ||
| 206 | Valid Range: 0-2 (0=legacy, 1=MSI, 2=MSI-X) | ||
| 207 | Default Value: 2 | ||
| 208 | |||
| 209 | Allows changing the interrupt mode at module load time, without requiring a | ||
| 210 | recompile. If the driver load fails to enable a specific interrupt mode, the | ||
| 211 | driver will try other interrupt modes, from least to most compatible. The | ||
| 212 | interrupt order is MSI-X, MSI, Legacy. If specifying MSI (IntMode=1) | ||
| 213 | interrupts, only MSI and Legacy will be attempted. | ||
| 214 | |||
| 215 | CrcStripping | ||
| 216 | ------------ | ||
| 217 | Valid Range: 0-1 | ||
| 218 | Default Value: 1 (enabled) | ||
| 219 | |||
| 220 | Strip the CRC from received packets before sending up the network stack. If | ||
| 221 | you have a machine with a BMC enabled but cannot receive IPMI traffic after | ||
| 222 | loading or enabling the driver, try disabling this feature. | ||
| 223 | |||
| 224 | WriteProtectNVM | ||
| 225 | --------------- | ||
| 226 | Valid Range: 0-1 | ||
| 227 | Default Value: 1 (enabled) | ||
| 228 | |||
| 229 | Set the hardware to ignore all write/erase cycles to the GbE region in the | ||
| 230 | ICHx NVM (non-volatile memory). This feature can be disabled by the | ||
| 231 | WriteProtectNVM module parameter (enabled by default) only after a hardware | ||
| 232 | reset, but the machine must be power cycled before trying to enable writes. | ||
| 233 | |||
| 234 | Note: the kernel boot option iomem=relaxed may need to be set if the kernel | ||
| 235 | config option CONFIG_STRICT_DEVMEM=y, if the root user wants to write the | ||
| 236 | NVM from user space via ethtool. | ||
| 237 | |||
| 238 | Additional Configurations | ||
| 239 | ========================= | ||
| 240 | |||
| 241 | Jumbo Frames | ||
| 242 | ------------ | ||
| 243 | Jumbo Frames support is enabled by changing the MTU to a value larger than | ||
| 244 | the default of 1500. Use the ifconfig command to increase the MTU size. | ||
| 245 | For example: | ||
| 246 | |||
| 247 | ifconfig eth<x> mtu 9000 up | ||
| 248 | |||
| 249 | This setting is not saved across reboots. | ||
| 250 | |||
| 251 | Notes: | ||
| 252 | |||
| 253 | - The maximum MTU setting for Jumbo Frames is 9216. This value coincides | ||
| 254 | with the maximum Jumbo Frames size of 9234 bytes. | ||
| 255 | |||
| 256 | - Using Jumbo Frames at 10 or 100 Mbps is not supported and may result in | ||
| 257 | poor performance or loss of link. | ||
| 258 | |||
| 259 | - Some adapters limit Jumbo Frames sized packets to a maximum of | ||
| 260 | 4096 bytes and some adapters do not support Jumbo Frames. | ||
| 261 | |||
| 262 | |||
| 263 | Ethtool | ||
| 264 | ------- | ||
| 265 | The driver utilizes the ethtool interface for driver configuration and | ||
| 266 | diagnostics, as well as displaying statistical information. We | ||
| 267 | strongly recommend downloading the latest version of Ethtool at: | ||
| 268 | |||
| 269 | http://sourceforge.net/projects/gkernel. | ||
| 270 | |||
| 271 | Speed and Duplex | ||
| 272 | ---------------- | ||
| 273 | Speed and Duplex are configured through the Ethtool* utility. For | ||
| 274 | instructions, refer to the Ethtool man page. | ||
| 275 | |||
| 276 | Enabling Wake on LAN* (WoL) | ||
| 277 | --------------------------- | ||
| 278 | WoL is configured through the Ethtool* utility. For instructions on | ||
| 279 | enabling WoL with Ethtool, refer to the Ethtool man page. | ||
| 280 | |||
| 281 | WoL will be enabled on the system during the next shut down or reboot. | ||
| 282 | For this driver version, in order to enable WoL, the e1000e driver must be | ||
| 283 | loaded when shutting down or rebooting the system. | ||
| 284 | |||
| 285 | In most cases Wake On LAN is only supported on port A for multiple port | ||
| 286 | adapters. To verify if a port supports Wake on LAN run ethtool eth<X>. | ||
| 287 | |||
| 288 | |||
| 289 | Support | ||
| 290 | ======= | ||
| 291 | |||
| 292 | For general information, go to the Intel support website at: | ||
| 293 | |||
| 294 | www.intel.com/support/ | ||
| 295 | |||
| 296 | or the Intel Wired Networking project hosted by Sourceforge at: | ||
| 297 | |||
| 298 | http://sourceforge.net/projects/e1000 | ||
| 299 | |||
| 300 | If an issue is identified with the released source code on the supported | ||
| 301 | kernel with a supported adapter, email the specific information related | ||
| 302 | to the issue to e1000-devel@lists.sf.net | ||
