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Subject: Re: [OMPI users] slowdown with infiniband and latest CentOS kernel
From: Dave Love (d.love_at_[hidden])
Date: 2014-03-04 05:43:54


Bernd Dammann <bd_at_[hidden]> writes:

> We use Moab/Torque, so we could use cpusets (but that has had some
> other side effects earlier, so we did not implement it in our setup).

I don't know remember Torque does, but core binding and (Linux) cpusets
are somewhat orthogonal. While a cpuset will obviously restrict the
processes somewhat, it won't provide the necessary binding (at least
unless the resource manager launches the processes and uses a cpuset for
each).

> Regardless of that, it looks strange to me, that this combination of
> kernel and OMPI has such a negative side effect on application
> performance.

I assume you can determine whether or not it's the kernel rather than
ompi/ofed by booting into the old one.