[openib-general] performance tests uploaded to contrib

[Michael S. Tsirkin]

Hello!
I created https://openib.org/svn/trunk/contrib/mellanox/perftest

This directory includes gen2 uverbs microbenchmarks -
useful as usage examples and for performance tuning.

Testing methodology:
- CPU clock instruction is used to get CPU clock without context switch.
- Median (as opposed to average) result is reported. The median is
  less sensitive to extreme scores. An option to report the full result
  distribution for alternative statistical analysis is provided.

Architectures supported:
- i686, x86_64

Tests in this directory: there is currently one test:

rdma_lat.c - latency test with RDMA write transactions

Code is originally based on the pingping test.
I intentionally did not rename functions from pingpong_ to rdma_
to make it easier to share some code with libibverbs/examples later.

Current results:

I currently observe latency below 3.5 usec.

Drop me a note if you find this useful.

Thanks,

-- 
MST - Michael S. Tsirkin