ARSC HPC Users' Newsletter 220, May 17, 2001

See you at CUG

Both editors of this newsletter are working on talks for CUG next week (which might, possibly, have something to do with the brevity of this issue). If you're going to CUG, you might try to catch these talks:

Monday, session 3A, Tom Baring (ARSC) and Jeff McAllister (ARSC)

The first SV1e processor upgrade at a user site was accomplished at the Arctic Region Supercomputing Center (ARSC) on April 11, 2001. In this talk, we will discuss performance data collected on several significant user codes. Of particular interest are issues related to the SV1/SV1e cache, memory, and MSPs.

Tuesday, session 6A, Robert Bell (CSIRO) and Guy Robinson (ARSC)

The NEC SX-5 and the Cray SV1 are the only shared-memory vector computers currently being marketed. This compares with at least five models a few years ago (J90, T90, SX-4, Fujitsu and Hitachi), with IBM, Digital, Convex, CDC and others having fallen by the wayside in the early 1990s. In this presentation, some comparisons will be made between the architecture of the survivors SX-5 and the SV1, and some performance comparisons will be given on benchmark and applications codes, and in areas not usually presented in comparisons, e.g. file systems, network performance, gzip speeds, compilation speeds, scalability and tools and libraries.

Also, ARSC staff Barbara Horner-Miller, Virginia Bedford, and Guy Robinson are all session chairs.

NCSA Meeting to use Access Grid Node

The NCSA Alliance will be broadcasting keynotes and other portions of their Private Sector and All Hands meetings on the Access Grid May 22-25. Please pass the word and join us. We will be in the Windmer.


Keynote Speaker: Michael Tiemann, Redhat CTO Keynote Speaker: Dave Turek, IBM's Vice President of Deep Computing & Web Servers for the Server Group Keynote Speaker: Dan Reed, Director of the National Computational Science Alliance

There will also be panels on the Access Grid, Linux Clusters, Computational Grids, Future Directions, and Scaleable Displays.

See: for information and agendas for the PSP and All Hands meetings.

Quick-Tip Q & A

A:[[ I wanted to share one data file with my group, so I did this:
  [[   chmod g+r ~/FunnelWort/19930201/data001
  [[ I know, I must also chmod all subdirectories in the path.  This is a
  [[ pain. Often I forget this step, and the only way I know how is
  [[ individually:
  [[   chmod g+rX ~/FunnelWort/19930201/
  [[   chmod g+rX ~/FunnelWort
  [[   chmod g+rX ~
  [[ (Using "chmod -R" is not an option, as I don't want to share
  [[ everything.)
  [[ Is there a better way to give group access to a file down the
  [[ directory tree?

  Dale Clark of ARSC provided both a one-line perl command to do the
  trick, and a nice script.  He wasn't entirely satisfied with the
  one-liner, so I'm skipping it, and just including the script. (I've
  already copied into my own ~/bin directory for future use.)


# Change permissions for a node and any owned node in its path.

$CHMOD = '/bin/chmod';
Usage:   $0 <chmod_args> <node_to_chmod>
Example: $0 g+rX ~/FunnelWort/19930201/data001

if (2 != @ARGV)
  print STDERR $USAGE;
  $ChmodArgs = $ARGV[0];
  $Node      = $ARGV[1];
  if (not -e $Node)
    printf STDERR qq
Unable to access "$Node"%s.\n
,$! ? ": $!" : '';
    until ($Done)
      if (not -o $Node)
        $Done = 1;
        print STDOUT "$CHMOD $ChmodArgs $Node\n";
        if (system $CHMOD,$ChmodArgs,$Node) # Returns non-zero on error.
          $Done = 1;
          $Node =~ s
          $Done = '' eq $1;

Q: I've inherited a Fortran program which uses implicit variable typing,
   and has problems.  As the new "maintainer" of this program, I need to
   clean it up.

   First, I plan to insert IMPLICIT NONE directives in every file and
   write explicit declarations for every variable.  Is there an easy way
   to do this, or do I need to go through the code line-by-line?

[[ Answers, Questions, and Tips Graciously Accepted ]]

Current Editors:
Ed Kornkven ARSC HPC Specialist ph: 907-450-8669
Kate Hedstrom ARSC Oceanographic Specialist ph: 907-450-8678
Arctic Region Supercomputing Center
University of Alaska Fairbanks
PO Box 756020
Fairbanks AK 99775-6020
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