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Subject: Re: [OMPI devel] [OMPI svn-full] svn:open-mpi r25445
From: George Bosilca (bosilca_at_[hidden])
Date: 2011-11-07 18:55:04


On Nov 7, 2011, at 17:34 , Barrett, Brian W wrote:

> I'm not sure why they called it vader, but vader is a fairly straight
> forward shared memory BTL. It differs from sm in two important ways: 1)
> it uses the XPMEM driver instead of SysV for shared memory and 2) it uses
> the the Nemesis queue structure from MPICH instead of ring buffers. XPMEM
> allows you to map large quantities of memory from other processes into
> your memory space, so you can do single copy for long messages, and the
> Nemesis queue seems to give better scaling on our larger SMPs. The Vader
> BTL does not require the 128 bit keys.

Brian,

Is there any data you can share to corroborate the scalability statement? No visible impact on the performance?

Nemesis way or ours was a hot topic for a long time ...

  george.