Re: 2nd beta preview looking good!

jcduell_at_lbl_dot_gov
Date: Mon Aug 15 2005 - 13:04:23 PDT

  • Next message: Marc L. Smith: "Re: 2nd beta preview looking good!"
    On Mon, Aug 15, 2005 at 03:50:07PM -0400, Marc L. Smith wrote:
    > 
    > I haven't noticed any complaints at runtime, but just to be sure...   
    > I set my environment vars sets as follows:
    > GASNET_SPAWNFN=S
    > SSH_SERVERS="n1 n2 n3 n4 n1 n2 n3 n4"
    > 
    > I listed n1-n4 in twice, because each of my four nodes has two  
    > processors. I ordered them as I did because it appeared to determine  
    > allocation of threads to processors, and I wanted even fan-out (e.g.,  
    > if I ran a program with 4 threads, and listed servers via "n1 n1 n2  
    > n2...", then the four threads were allocated by default, 2 per node,  
    > to nodes n1 and n2.  Is this correct?
    
    You could actually have used just
    
      SSH_SERVERS="n1 n2 n3 n4"
    
    I.e., the list is per *process* in the job, not per-UPC thread.  There's
    no difference for non-pthreaded jobs, but there is for pthreaded ones.
    
    I need to document this.  Thanks for noticing!
    
    Finally, you can use $SSH_SERVERS, but it's deprecated.  $UPC_NODES (or
    $UPC_NODEFILE) is now preferred.
    
    -- 
    Jason Duell             Future Technologies Group
    <jcduell_at_lbl_dot_gov>       Computational Research Division
    Tel: +1-510-495-2354    Lawrence Berkeley National Laboratory
    

  • Next message: Marc L. Smith: "Re: 2nd beta preview looking good!"