Manual Pages  — BXE

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

if_bxe_load="YES"

Special care must be taken when modifying the number of queues and receive buffers. FreeBSD imposes a limit on the maximum number of mbuf(9) allocations. If buffer allocations fail, the interface initialization will fail and the interface will not be usable. The driver does not make a best effort for buffer allocations. It is an all or nothing effort.

You can tweak the mbuf(9) allocation limit using sysctl(8) and view the current usage with netstat(1) as follows:

# netstat -m
# sysctl kern.ipc.nmbclusters
# sysctl kern.ipc.nmbclusters=<#>

There are additional configuration parameters that can be set on a per-instance basis to dynamically override the default configuration. The '#' below must be replaced with the driver instance / interface unit number:

dev.bxe.#.debug
	DEFAULT = 0 Sets the default logging level of the driver instance. See hw.bxe.debug above and the Diagnostics and Debugging section below for more details.
dev.bxe.#.rx_budget
	DEFAULT = 0xffffffff Sets the maximum number of receive packets to process in an interrupt for the driver instance. See hw.bxe.rx_budget above for more details.

Additional items can be configured using ifconfig(8):

MTU - Maximum Transmission Unit
	DEFAULT = 1500 RANGE = 46-9184 # ifconfig bxe# mtu <n>
Promiscuous Mode
	DEFAULT = OFF # ifconfig bxe# [ promisc | -promisc ]
Rx/Tx Checksum Offload
	DEFAULT = RX/TX CSUM ON Note that the Rx and Tx settings are not independent. # ifconfig bxe# [ rxcsum | -rxcsum | txcsum | -txcsum ]
TSO - TCP Segmentation Offload
	DEFAULT = ON # ifconfig bxe# [ tso | -tso | tso6 | -tso6 ]
LRO - TCP Large Receive Offload
	DEFAULT = ON # ifconfig bxe# [ lro | -lro ]

To dump the default driver configuration:

# sysctl -a | grep hw.bxe

To dump every instance's configuration and detailed statistics:

# sysctl -a | grep dev.bxe

To dump information for a single instance (replace the '#' with the driver instance / interface unit number):

# sysctl -a | grep dev.bxe.#

To dump information for all the queues of a single instance:

# sysctl -a | grep dev.bxe.#.queue

To dump information for a single queue of a single instance (replace the additional '#' with the queue number):

# sysctl -a | grep dev.bxe.#.queue.#

The bxe driver has the ability to dump a ton of debug messages to the system log. The default level of logging can be set with the hw.bxe.debug sysctl(8). Take care with this setting as it can result in too many logs being dumped. Since this parameter is the default one, it affects every instance and will dramatically change the timing in the driver. A better alternative to aid in debugging is to dynamically change the debug level of a specific instance with the dev.bxe.#.debug sysctl(8). This allows you to turn on/off logging of various debug groups on-the-fly.

The different debug groups that can be toggled are:

DBG_LOAD   0x00000001 /* load and unload    */
DBG_INTR   0x00000002 /* interrupt handling */
DBG_SP     0x00000004 /* slowpath handling  */
DBG_STATS  0x00000008 /* stats updates      */
DBG_TX     0x00000010 /* packet transmit    */
DBG_RX     0x00000020 /* packet receive     */
DBG_PHY    0x00000040 /* phy/link handling  */
DBG_IOCTL  0x00000080 /* ioctl handling     */
DBG_MBUF   0x00000100 /* dumping mbuf info  */
DBG_REGS   0x00000200 /* register access    */
DBG_LRO    0x00000400 /* lro processing     */
DBG_ASSERT 0x80000000 /* debug assert       */
DBG_ALL    0xFFFFFFFF /* flying monkeys     */

For example, to debug an issue in the receive path on bxe0:

# sysctl dev.bxe.0.debug=0x22

When finished turn the logging back off:

# sysctl dev.bxe.0.debug=0