Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Linux* Driver for Intel(R) Ethernet Network Connection 2 ====================================================== 3 4 Intel Gigabit Linux driver. 5 Copyright(c) 1999 - 2013 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 default behaviour of the driver previously assumed a static 65 InterruptThrottleRate value of 8000, providing a good fallback value for 66 all traffic types, but lacking in small packet performance and latency. 67 The hardware can handle many more small packets per second however, and 68 for this reason an adaptive interrupt moderation algorithm was implemented. 69 70 The driver has two adaptive modes (setting 1 or 3) in which 71 it dynamically adjusts the InterruptThrottleRate value based on the traffic 72 that it receives. After determining the type of incoming traffic in the last 73 timeframe, it will adjust the InterruptThrottleRate to an appropriate value 74 for that traffic. 75 76 The algorithm classifies the incoming traffic every interval into 77 classes. Once the class is determined, the InterruptThrottleRate value is 78 adjusted to suit that traffic type the best. There are three classes defined: 79 "Bulk traffic", for large amounts of packets of normal size; "Low latency", 80 for small amounts of traffic and/or a significant percentage of small 81 packets; and "Lowest latency", for almost completely small packets or 82 minimal traffic. 83 84 In dynamic conservative mode, the InterruptThrottleRate value is set to 4000 85 for traffic that falls in class "Bulk traffic". If traffic falls in the "Low 86 latency" or "Lowest latency" class, the InterruptThrottleRate is increased 87 stepwise to 20000. This default mode is suitable for most applications. 88 89 For situations where low latency is vital such as cluster or 90 grid computing, the algorithm can reduce latency even more when 91 InterruptThrottleRate is set to mode 1. In this mode, which operates 92 the same as mode 3, the InterruptThrottleRate will be increased stepwise to 93 70000 for traffic in class "Lowest latency". 94 95 In simplified mode the interrupt rate is based on the ratio of TX and 96 RX traffic. If the bytes per second rate is approximately equal, the 97 interrupt rate will drop as low as 2000 interrupts per second. If the 98 traffic is mostly transmit or mostly receive, the interrupt rate could 99 be as high as 8000. 100 101 Setting InterruptThrottleRate to 0 turns off any interrupt moderation 102 and may improve small packet latency, but is generally not suitable 103 for bulk throughput traffic. 104 105 NOTE: InterruptThrottleRate takes precedence over the TxAbsIntDelay and 106 RxAbsIntDelay parameters. In other words, minimizing the receive 107 and/or transmit absolute delays does not force the controller to 108 generate more interrupts than what the Interrupt Throttle Rate 109 allows. 110 111 NOTE: When e1000e is loaded with default settings and multiple adapters 112 are in use simultaneously, the CPU utilization may increase non- 113 linearly. In order to limit the CPU utilization without impacting 114 the overall throughput, we recommend that you load the driver as 115 follows: 116 117 modprobe e1000e InterruptThrottleRate=3000,3000,3000 118 119 This sets the InterruptThrottleRate to 3000 interrupts/sec for 120 the first, second, and third instances of the driver. The range 121 of 2000 to 3000 interrupts per second works on a majority of 122 systems and is a good starting point, but the optimal value will 123 be platform-specific. If CPU utilization is not a concern, use 124 RX_POLLING (NAPI) and default driver settings. 125 126 RxIntDelay 127 ---------- 128 Valid Range: 0-65535 (0=off) 129 Default Value: 0 130 131 This value delays the generation of receive interrupts in units of 1.024 132 microseconds. Receive interrupt reduction can improve CPU efficiency if 133 properly tuned for specific network traffic. Increasing this value adds 134 extra latency to frame reception and can end up decreasing the throughput 135 of TCP traffic. If the system is reporting dropped receives, this value 136 may be set too high, causing the driver to run out of available receive 137 descriptors. 138 139 CAUTION: When setting RxIntDelay to a value other than 0, adapters may 140 hang (stop transmitting) under certain network conditions. If 141 this occurs a NETDEV WATCHDOG message is logged in the system 142 event log. In addition, the controller is automatically reset, 143 restoring the network connection. To eliminate the potential 144 for the hang ensure that RxIntDelay is set to 0. 145 146 RxAbsIntDelay 147 ------------- 148 Valid Range: 0-65535 (0=off) 149 Default Value: 8 150 151 This value, in units of 1.024 microseconds, limits the delay in which a 152 receive interrupt is generated. Useful only if RxIntDelay is non-zero, 153 this value ensures that an interrupt is generated after the initial 154 packet is received within the set amount of time. Proper tuning, 155 along with RxIntDelay, may improve traffic throughput in specific network 156 conditions. 157 158 TxIntDelay 159 ---------- 160 Valid Range: 0-65535 (0=off) 161 Default Value: 8 162 163 This value delays the generation of transmit interrupts in units of 164 1.024 microseconds. Transmit interrupt reduction can improve CPU 165 efficiency if properly tuned for specific network traffic. If the 166 system is reporting dropped transmits, this value may be set too high 167 causing the driver to run out of available transmit descriptors. 168 169 TxAbsIntDelay 170 ------------- 171 Valid Range: 0-65535 (0=off) 172 Default Value: 32 173 174 This value, in units of 1.024 microseconds, limits the delay in which a 175 transmit interrupt is generated. Useful only if TxIntDelay is non-zero, 176 this value ensures that an interrupt is generated after the initial 177 packet is sent on the wire within the set amount of time. Proper tuning, 178 along with TxIntDelay, may improve traffic throughput in specific 179 network conditions. 180 181 Copybreak 182 --------- 183 Valid Range: 0-xxxxxxx (0=off) 184 Default Value: 256 185 186 Driver copies all packets below or equaling this size to a fresh RX 187 buffer before handing it up the stack. 188 189 This parameter is different than other parameters, in that it is a 190 single (not 1,1,1 etc.) parameter applied to all driver instances and 191 it is also available during runtime at 192 /sys/module/e1000e/parameters/copybreak 193 194 SmartPowerDownEnable 195 -------------------- 196 Valid Range: 0-1 197 Default Value: 0 (disabled) 198 199 Allows PHY to turn off in lower power states. The user can set this parameter 200 in supported chipsets. 201 202 KumeranLockLoss 203 --------------- 204 Valid Range: 0-1 205 Default Value: 1 (enabled) 206 207 This workaround skips resetting the PHY at shutdown for the initial 208 silicon releases of ICH8 systems. 209 210 IntMode 211 ------- 212 Valid Range: 0-2 (0=legacy, 1=MSI, 2=MSI-X) 213 Default Value: 2 214 215 Allows changing the interrupt mode at module load time, without requiring a 216 recompile. If the driver load fails to enable a specific interrupt mode, the 217 driver will try other interrupt modes, from least to most compatible. The 218 interrupt order is MSI-X, MSI, Legacy. If specifying MSI (IntMode=1) 219 interrupts, only MSI and Legacy will be attempted. 220 221 CrcStripping 222 ------------ 223 Valid Range: 0-1 224 Default Value: 1 (enabled) 225 226 Strip the CRC from received packets before sending up the network stack. If 227 you have a machine with a BMC enabled but cannot receive IPMI traffic after 228 loading or enabling the driver, try disabling this feature. 229 230 WriteProtectNVM 231 --------------- 232 Valid Range: 0,1 233 Default Value: 1 234 235 If set to 1, configure the hardware to ignore all write/erase cycles to the 236 GbE region in the ICHx NVM (in order to prevent accidental corruption of the 237 NVM). This feature can be disabled by setting the parameter to 0 during initial 238 driver load. 239 NOTE: The machine must be power cycled (full off/on) when enabling NVM writes 240 via setting the parameter to zero. Once the NVM has been locked (via the 241 parameter at 1 when the driver loads) it cannot be unlocked except via power 242 cycle. 243 244 Additional Configurations 245 ========================= 246 247 Jumbo Frames 248 ------------ 249 Jumbo Frames support is enabled by changing the MTU to a value larger than 250 the default of 1500. Use the ifconfig command to increase the MTU size. 251 For example: 252 253 ifconfig eth<x> mtu 9000 up 254 255 This setting is not saved across reboots. 256 257 Notes: 258 259 - The maximum MTU setting for Jumbo Frames is 9216. This value coincides 260 with the maximum Jumbo Frames size of 9234 bytes. 261 262 - Using Jumbo frames at 10 or 100 Mbps is not supported and may result in 263 poor performance or loss of link. 264 265 - Some adapters limit Jumbo Frames sized packets to a maximum of 266 4096 bytes and some adapters do not support Jumbo Frames. 267 268 - Jumbo Frames cannot be configured on an 82579-based Network device, if 269 MACSec is enabled on the system. 270 271 ethtool 272 ------- 273 The driver utilizes the ethtool interface for driver configuration and 274 diagnostics, as well as displaying statistical information. We 275 strongly recommend downloading the latest version of ethtool at: 276 277 https://kernel.org/pub/software/network/ethtool/ 278 279 NOTE: When validating enable/disable tests on some parts (82578, for example) 280 you need to add a few seconds between tests when working with ethtool. 281 282 Speed and Duplex 283 ---------------- 284 Speed and Duplex are configured through the ethtool* utility. For 285 instructions, refer to the ethtool man page. 286 287 Enabling Wake on LAN* (WoL) 288 --------------------------- 289 WoL is configured through the ethtool* utility. For instructions on 290 enabling WoL with ethtool, refer to the ethtool man page. 291 292 WoL will be enabled on the system during the next shut down or reboot. 293 For this driver version, in order to enable WoL, the e1000e driver must be 294 loaded when shutting down or rebooting the system. 295 296 In most cases Wake On LAN is only supported on port A for multiple port 297 adapters. To verify if a port supports Wake on Lan run ethtool eth<X>. 298 299 Support 300 ======= 301 302 For general information, go to the Intel support website at: 303 304 www.intel.com/support/ 305 306 or the Intel Wired Networking project hosted by Sourceforge at: 307 308 http://sourceforge.net/projects/e1000 309 310 If an issue is identified with the released source code on the supported 311 kernel with a supported adapter, email the specific information related 312 to the issue to e1000-devel@lists.sf.net