[ewg] Interop test failure using OFED-3.5 RC4

[Elken, Tom]

> Rupert and the UNH-IOL pointed out that an Interop test which uses the
> ib_read_bw (perftest) benchmark fails on Intel True Scale HCAs.
> This test was succeeding with RC2, and started failing with RC3.  I am sorry that
> our QA team did not find this bug with RC3.
> 
> We have investigated and found that perftest was upgraded from v1.8 to v2.0
> on 11/19/12, between RC3 and RC4.
 
Er, I meant "between RC2 and RC3."

-Tom

> We verified that with the qib driver in OFED-3.5 RC4 and the perftest RPM from
> RC2, we pass the tests.
> We also ran a similar qperf RDMA read test with qperf and qib from RC4 and that
> test passed.
> 
> We are working to isolate the bug and develop a fix.  We suspect the perftest
> changes, but the ib_read_* benchmarks may just have changed enough to start
> checking a part of the spec which hasn't been tested before in Interop tests.  So
> it may be a qib driver issue.
> 
> The EWG standard practice is that if a significant bug fix goes in, we would need
> another RC to enable others to easily test it.
> But perhaps it depends on whether the bug is in perftest, qib or elsewhere.  In
> any case, we don't want a GA build until this issue is solved.
> 
> Regards,
> Tom