Re: 2nd beta preview looking good!

From: Marc L. Smith (mlsmith_at_colby_dot_edu)
Date: Mon Aug 15 2005 - 12:50:07 PDT

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    On Aug 15, 2005, at 3:21 PM, jcduell_at_lbl_dot_gov wrote:
    > Thanks for the feedback, Marc.
    > I notice that UDP is the default network for your install.  We've
    > improved our documentation for how to run UDP-based programs in this
    > beta, and UPC executables now provide a helpful message if you try to
    > run them over UDP without the right setup (i.e., without telling the
    > runtime which hosts to run the job on).
    I haven't noticed any complaints at runtime, but just to be sure...   
    I set my environment vars sets as follows:
    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?
    > I remember you were thinking of using UPC for a course you'll be
    > teaching.  We'd love to hear how that goes.  Please have have your
    > students send us bug reports for any issues they encounter (extra  
    > credit
    > for each bug reported?)
    Yes, in fact I've chosen the UPC text by El-Ghazawi.  The course  
    won't be purely UPC programming, but UPC is one of the main languages  
    students will learn to program in.  I've been through the UPC text  
    and think it is, like UPC itself, and K&R, a very concise, useful,  
    and elegant book. I'm sure GCC's support of UPC will encourage  
    students that UPC is not merely an academic language -- though I'm  
    going to take your advice and stick with Berkeley for translation and  
    runtime.  :-)
    I'll also be using TCP Linda (by Scientific Computing Associates) as  
    another example of a distributed shared memory model.  I think  
    together, UPC and Linda/Tuple Space models will give students a broad  
    sense of shared memory concurrency.  For message passing, we'll be  
    using either JCSP or occam (two realizations of Hoare's CSP model of  
    concurrency).  I've opted not to cover MPI.  I hope I don't offend  
    anyone on this list, but I fear MPI is so large it is overwhelming  
    for students.  In contrast, UPC and Linda are quite elegant, as are  
    JCSP and occam, with only a few programming constructs to learn and  
    Thanks for all your support.  I'm not anticipating any problems with  
    UPC, but I'll let you know how things are going, and be sure to pass  
    along any perceived bugs we encounter.
    > Cheers,
    > -- 
    > Jason Duell             Future Technologies Group
    > <jcduell_at_lbl_dot_gov>       Computational Research Division
    > Tel: +1-510-495-2354    Lawrence Berkeley National Laboratory

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