March 22nd, 2011

OFED, 10gigE, and SUJ

I have merged the OFED 1.5.3 Infiniband stack into FreeBSD CURRENT. We have achieved feature and performance parity with the Linux stack using a combination of wrappers and re-implementation of sensitive pieces. lwn wrote an article about the wrapper work here. Some FreeBSD developers are understandably concerned about growing a Linux kernel compat layer and how that could lower the quality of FreeBSD drivers. I don't foresee this as a real complication but only time will tell.

I'm working on bringing in support for Mellanox's 10gigE adapters now. It's always interesting for me to explore different directions operating systems take to accomplish the same features. Network buffering is one of those areas that is starkly different across operating systems. Maybe that deserves its own post.

I am now looking for bug reports for SUJ for another round of bug-fixing before 9.0 ships. There are a couple of areas where performance isn't great due to latency involved in blocking journal writes. I know how to eliminate these but it will take some time to implement. We are hoping to ship SUJ as the default in 9.0 and then I may provide an official backport to 8.x.