Known issues – Dell Intel PRO Family of Adapters User Manual
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NAPI
NAPI (Rx polling mode) is supported in the e1000e driver. NAPI can reduce the overhead of packet receiving by using
polling instead of interrupt-based processing. NAPI is enabled by default. To override the default, use the following
compile-time flags.
To disable NAPI, specify this additional compiler flag when compiling the driver module:
# make CFLAGS_EXTRA=-DE1000E_NO_NAPI install
To enable NAPI, specify this additional compiler flag when compiling the driver module:
# make CFLAGS_EXTRA=-DE1000E_NAPI install
See
for more information on NAPI.
Enabling a Separate Vector for TX
# make CFLAGS_EXTRA=-DCONFIG_E1000E_SEPARATE_TX_HANDLER
This allows a separate handler for transmit cleanups. This may be useful if you have many CPU cores under heavy
load and want to distribute the processing load.
With this option, three MSI-X vectors are used: one for TX, one for RX and one for link.
Known Issues
Detected Tx Unit Hang in Quad Port Adapters
In some cases ports 3 and 4 don't pass traffic and report 'Detected Tx Unit Hang' followed by 'NETDEV WATCHDOG:
ethX: transmit timed out' errors. Ports 1 and 2 don't show any errors and will pass traffic.
This issue MAY be resolved by updating to the latest kernel and BIOS. The user is encouraged to run an OS that fully
supports MSI interrupts. You can check your system's BIOS by downloading the Linux Firmware Developer Kit that can
be obtained at
.
Dropped Receive Packets on Half-duplex 10/100 Networks
If you have an Intel PCI Express adapter running at 10 Mbps or 100 Mbps, half-duplex, you may observe occasional
dropped receive packets. There are no workarounds for this problem in this network configuration. The network must
be updated to operate in full-duplex and/or 1000 Mbps only.
Compiling the Driver
When trying to compile the driver by running make install, the following error may occur:
"Linux kernel source not configured - missing version.h"
To solve this issue, create the version.h file by going to the Linux Kernel source tree and entering:
# make include/linux/version.h
Performance Degradation with Jumbo Frames
Degradation in throughput performance may be observed in some Jumbo frames environments. If this is observed,
increasing the application's socket buffer size and/or increasing the /proc/sys/net/ipv4/tcp_*mem entry values may help.
For more details, see the specific application documentation and the text file located in /us-
r/src/linux*/Documentation/networking/ip-sysctl.txt.
Jumbo frames on Foundry BigIron 8000 Switch
There is a known issue using Jumbo frames when connected to a Foundry BigIron 8000 switch. This is a 3rd party lim-
itation. If you experience loss of packets, lower the MTU size.