FW: MPICH, malloc, and my impending assault of one (1) beowulf cluster
Chris Richard Adams
chrisa at ASPATECH.COM.BR
Thu Aug 2 12:39:54 EDT 2001
From: Chris Richard Adams
Sent: Thursday, August 02, 2001 12:38 PM
To: 'mundy erik'
Subject: RE: MPICH, malloc, and my impending assault of one (1) beowulf
Hi Erik -
Admiting your abusiveness is the first and hardest step toward
healing..congratulations! I don't have a response to your problem, but
perhaps will run into that soon. Unfortuately I am just trying to get
the pi code to run. If I may ask...
1) did you use the example that comes with the beowulf install - found
in \usr\mpi-beowulf\examples? That directory has a pi example, but I
can't get the Make to work. Did you succeed? Can I just run MpiCC -o
2.) DO you know of any documentation for those examples, or perhaps
could you share a reference to an MPI example. I know C, but nothing
about MPI and just want some hello world examples.
From: mundy erik [mailto:erik.mundy at HAMPTONU.EDU]
Sent: Wednesday, July 18, 2001 4:35 PM
To: 'beowulf at beowulf.org'
Subject: MPICH, malloc, and my impending assault of one (1) beowulf
Hello, my name is Erik, and I am an MPICH abuser.
I am running a simple one master, two slave Beowulf test
RHL 6.1, kernel 2.4.4, MPICH 1.2.1, NFS mount from master to slave on
PII 400's. MPICH is giving me some serious headaches - every MPI
execute with a malloc in it crashes with the good old "p4 error:
SIGSEGV: 11" message. I have been experimenting with the test programs
come with MPICH for simplicity; for example, 'cpi' runs well on all
calculates pi, and I rejoice. Mpptest also works without a problem
any two of the three computers. But when I try to mpirun "sendrecv" or
"overtake" from examples/test/pt2pt (both of which use a malloc), MPICH
gives it the good old college try and then throws me the errors.
would just try to do as much as humanly possible to ignore this problem,
the code that this beowulf was designed for works when I execute it on
computer, and crashes rather spectacularly with the segmentation
error when I try to mpirun it, even on just one computer, leading me to
think that there is some sort of conflict between MPICH and malloc.
Granted, these computers aren't exactly state-of-the-art - each
only 128M ram with ~400M swap. But that should be more than enough to
execute those simple examples. Has anyone had trouble with the Linux
version of malloc in the past in a situation like this? If you shudder
you hear the words "malloc" and "MPICH" used in the same sentence,
email me back. This might be a bit difficult to track down, and I'm
not the best man for the job, all I did was build a beowulf :). I've
been on this list for the last two months but it's taught me that if
can help its probably you guys. I am EXTREMELY appreciative of any
assistance you can offer.
erik.mundy at hamptonu.edu
PS - also, I should mention that yes, the code I am trying to run WAS
designed for use with MPI, and yes, I did patch MPICH with the bug fixes
from the Argonne page. Sorry to take the obvious 'he's so dumb!'
away... I'm hoping there's one more that maybe I'm just missing :)
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