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What Is Infiniband?

InfiniBand (IB) is a high-speed (10-300Gb/s) low-latency (140–2600 ns) switched-fabric interconnect, developed primarily for HPC, but as of now widely adopted where its properties are in demand.

InfiniBand is supported on most major operating systems: Windows, Linux, (Open)Solaris, AIX, HP-UX, z/OS, among others. OpenFabrics Alliance (founded in 2004 as OpenIB Alliance) is developing a cross-platform IB/RDMA stack for Linux and Windows. The stack is released as OFED (OpenFabrics Enterprise Distribution) under both GPL and BSD licenses.

Infiniband in FreeBSD

The OFED stack was merged in March 2011 (http://jeffr-tech.livejournal.com/23467.html) and is available in FreeBSD 9.0 and later.

Proprietary IB stacks are known to exist outside of FreeBSD proper. In particular, three major storage appliance vendors – EMC/Isilon, NetApp, and Panasas – ship products based on FreeBSD and use InfiniBand for high-speed interconnects.

Infiniband hardware support by release

Card series Driver FreeBSD 9.x FreeBSD 10.x FreeBSD 11.x Comments
InfiniHost mthca Yes Yes Yes Not maintained
ConnectX mlx4 Yes Yes Yes
ConnectX-2 mlx4 Yes Yes Yes
ConnectX-3/Pro mlx4 Yes Yes Yes
ConnectX-4 (Eth) mlx5 No Yes Yes
ConnectX-4 (IB) mlx5 No Not Yet Not Yet In development
Connect-IB mlx5 No Not Yet Not Yet In development

Building OFED in FreeBSD

  • Add the following options to your KERNCONF to compile the necessary protocols/protocol options into your kernel:
options        OFED            # Infiniband protocol stack and support
options        SDP             # Sockets Direct Protocol for infiniband
options        IPOIB_CM        # Use connect mode ipoib
  • Add the OFED drivers to your KERNCONF (alternately you could use the MODULES_OVERRIDE variable in /etc/src.conf):
device         ipoib           # IP over IB devices
device         mlx4ib          # ConnectX Infiniband support
device         mlxen           # ConnectX Ethernet support
device         mthca           # Infinihost cards
  • Run buildkernel/installkernel per usual process.
  1. Add WITH_OFED='yes' to /etc/src.conf.
  2. Run buildworld/installworld per usual process.
  3. Set the “sys.device.mlx4_coreX.mlx4_portY” sysctl to either “eth” or “ib” depending on how you want the device ports to be configured.

Status

Mellanox engineers, et. al., have made substantial improvements to the IB stack in 2015/2016 to support the latest ConnectX HCAs. The freebsd-infiniband email archives contain discussions of progress and issues.

There are some outstanding work items for Infiniband/OFED on FreeBSD.

  • Upgrade to 1.5.x (Isilon). Delivery date: TBD.
  • Upgrade to 3.x (Isilon). Can't be done immediately because of refactoring done in the kernel.org branch and with the userland utilities, and the fact that things are still in a large degree of flux.
  • WITH_OFED doesn't cover all OFED stack utilities; a number of them need to be ported from Linux and contributed back to OFED (preferred) or rewritten to work with FreeBSD.

Feedback

There's an infiniband mailing list. If you're having issues or would like to provide feedback about the Infiniband stack on FreeBSD, you should subscribe and poke the mailing list.

References


Everything below is “work in progress”. It will be moved into the correct place on this page when it's ready B)

[more stuff to be worked on here]

  • infiniband.1461496269.txt.gz
  • Last modified: 2016/04/24 11:11
  • by JustinClift