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Subject: Re: [OMPI devel] sm BTL "extra procs"
From: Richard Graham (rlgraham_at_[hidden])
Date: 2008-12-23 09:05:16


Not needed now. Since we did not want to deal with trying to grow the
shared memory file after it's allocation, with all the required
synchronization, we allocated extra memory up front - for dynamic process
control. Since this has never been enabled, we really don't need this extra
memory.

Rich

On 12/22/08 11:47 AM, "Eugene Loh" <Eugene.Loh_at_[hidden]> wrote:

> Why does the sm BTL allocate "extra procs"?
>
> E.g.,
>
> https://svn.open-mpi.org/trac/ompi/browser/branches/v1.3/ompi/mca/btl/sm/btl_s
> m.c?version=19785#L403
>
> In particular:
>
> *) sm_max_procs is -1 (so there is no max)
> *) sm_sm_extra_procs (sic, this is the ompi_info name) is 2
>
> So, if there are n procs on the node, it allocates FIFOs for n*(n+2)
> connections. Why?
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