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Subject: Re: [OMPI devel] RFC: sm Latency
From: Eugene Loh (Eugene.Loh_at_[hidden])
Date: 2009-01-21 20:00:37


Ron Brightwell wrote:
If you poll only the queue that correspond to a posted receive, you only optimize micro-benchmarks, until they start using ANY_SOURCE.
    
Note that the HPCC RandomAccess benchmark only uses MPI_ANY_SOURCE (and
MPI_ANY_TAG).
  
But HPCC RandomAccess also just uses non-blocking receives.  So, it's kind of outside the scope of the original ideas here (bypassing the PML receive-request data structure).

It's possibly not even a poster child for the single-queue idea either.  Single queue probably shines best when you have to poll all connections for a few messages.  In contrast, RandomAccess (I think) loads all connections up randomly (pseudo-evenly).