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Subject: Re: [OMPI users] knem/openmpi performance?
From: Elken, Tom (tom.elken_at_[hidden])
Date: 2013-07-18 11:15:47


> "Elken, Tom" <tom.elken_at_[hidden]> writes:
> > there is a kcopy module
> > that assists shared memory MPI bandwidth in a way similar to knem.
>
> Somewhat OT, but is it documented? I went looking some time ago, and
> couldn't find anything more useful than the source.
[Tom]
Strangely no. Though there were some marketing/sales foils some time ago that played it up.

I have on my To-Do list to get more environment variables documented, including these two relevant to kcopy:

PSM_SHM_KCOPY=none =put, =get : 'put' is the default.

PSM_KASSIST_MODE =none =kcopy-put, =kcopy-get : 'kcopy-put' is the default.

So either of these could be used to turn off kcopy (using =none) so you could measure performance with and without kcopy.
The second of these is general enough to handle knem too. But we need testing before we can say that knem is supported.

-Tom

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