Scyld & linpack

Rick Niles niles at
Sat Apr 7 16:26:53 PDT 2001

> First of all, where are the source rpms so I can compile them for my
> architecture?

They were actually missing.  Sorry about that I just put it there.

> There is no documentation on them.  

124 of the 127 files in the hpl RPM are HPL man pages.

> Do they take any command lines?

I think you mean does the "linpack" shell script take any arguments.
No it's very simple and stupid.

> xhpl needs HPL.dat to run.  

Yes. The "linpack" script create it in "/tmp" on the fly.  The script
can give you a good start on what the file format should look like.

> Where do I need to put this file?

Annoyingly, it has to be in the same directory as the execuable.  That's
why I copy both in to "/tmp" before running.

> Would 'linpack' also use this file if it existed?  

No it creates it's own.  I'm happy to take patches to improve the complete
simplicity/stupidity of the current script.

> Is this running on the cluster at large?  

Yes. It counts the number of CPUs an then runs that many ranks.

Most of these questions can be answered by just reading the 48 line
"linpack" shell script.

> How do I make it run on just one/all machines?

Copy the script and modify it.

Add a line after the two "NCPUS" computation lines to force it a
certain value, like "NCPUS=4".

Also, I highly recommend playing with different dimensions.  Since I
wanted a simple script I always use a dimension of (1 x NCPUS) which
is far from ideal for most configurations.  See the HPL home page for
for information.

> /home/redhat/BUILD/glibc-2.1.3/elf/dlerror.c:152: undefined reference to `bproc_currnode'

In general, if you get this kind of link time problem building a package
that's looking for "bproc" something you need to add "-lbproc" to the
link line so that it includes the bproc library.

I hope this helps,

	Rick Niles
	Scyld Computing Corporation

More information about the Beowulf mailing list