Open Fabrics Enterprise Distribution (OFED)
- IPoIB in OFED 1.3.1 Release Notes
+ IPoIB in OFED 1.4 Release Notes
- June 2008
+ November 2008
===============================================================================
Even if the HCA does support SRQ, the administrator can force the driver to not
use SRQs. This can be done by setting the module parameter "set_nonsrq".
6. This version of ofed introduces improvements to IPOIB by cutting the CPU
- overhead in handling both send and receive packets. This will improve operation
- in different modes of operation but the change is mostly noticeable for small
- UDP message were message rate has increased.
-
- Stateless offload features have been introduced:
- checksum offload - generate on send and verify on receive of packet checksum
- Large Send Offload - support fragmenting a large quantity of data passed form the
- TCP/IP stack and fragment it to MSS sized packets.
-7. Support for interrupt moderation was introduced. This is done for HCAs which
- support this feature (like Mellanox's mlx4). Controlling moderation params is
- done through the ethtool interface.
-
- ethtool -c ib0
- will display the parameters for ib0. Two kinds of parameters are supported:
- rx-usecs, tx_usecs and rx-frames, tx_frames - value for rx and tx are identical.
- To change a value you need to do:
- ethtool -C ib0 rx-usecs <new val>
- This will change both rx_usecs and tx_usecs for ib0.
-
- The semantics of the parameters is this: an EQE will be pushed to the event queue
- if any of the conditions have been met - *-usecs have elapsed or *-frames were
- received since the last time an EQE was generated. Using this helps reduce
- interrupt rate generated by the device.
-8. 4K mtu support has been introduced. In order to benefit from using 4K mtu it is
- required that the SM create the broadcast group with 4K MTU. See SM
- documentation for details.
+ overhead in handling receive packets. This will improve operation
+ in datagram mode:
+ Large Receive Offload - aggregating multiple incoming packets from a single
+ stream into a larger buffer before they are passed higher up the networking
+ stack, thus reducing the number of packets that have to be processed.
Usage and configuration:
========================
1. To check the current mode used for outgoing connections, enter:
cat /sys/class/net/ib0/mode
2. To disable IPoIB CM at compile time, enter:
- cd OFED-1.3
+ cd OFED-1.4
export OFA_KERNEL_PARAMS="--without-ipoib-cm"
- ./install.sh
+ ./install.pl
3. To change the run-time configuration for IPoIB, enter:
edit /etc/infiniband/openib.conf, change the following parameters:
# Enable IPoIB Connected Mode
These alias lines cause the drivers to be loaded again by udev scripts.
Workaround: Change modprobe.conf to set
- OFA_KERNEL_PARAMS="--without-modprobe" before running install.sh, or remove
+ OFA_KERNEL_PARAMS="--without-modprobe" before running install.pl, or remove
the alias lines from modprobe.conf.
3. On SLES 10: