Kevin Ying kying at pppl.gov
Fri Nov 1 13:23:51 PST 2002

Hi JC,

You may set P4_GLOBMEMSIZE (a shell variable) to a larger value, but not
bigger than your kernel predefined max shared memory value.  For example, I
put following lines in my .bashrc file


You may use sysctl to find out the kernel predefined max.

- Kevin Ying

Princeton Plasma Physics Laboratory
P.O. Box 451, MS-09
Princeton, NJ 08543-0451

Email : kying at princeton.edu
Phone : (609) 243-2718

-----Original Message-----
From: beowulf-admin at beowulf.org [mailto:beowulf-admin at beowulf.org]On
Behalf Of Jean-Christophe Ducom
Sent: Friday, November 01, 2002 10:48 AM
To: beowulf
Subject: P4_GLOBMEMSIZE problem

When I try to run a charmm job (w/ modified sizes files) on 1Gb SMP
nodes, I get the following error message:

p8_12489: (6.243597) xx_shmalloc: returning NULL; requested 3801600 bytes
p8_12489: (6.243731) p4_shmalloc returning NULL; request = 3801600 bytes
You can increase the amount of memory by setting the environment variable
P4_GLOBMEMSIZE (in bytes); the current size is 4194304
p8_12489:  p4_error: alloc_p4_msg failed: 0
Broken pipe

What I am missing? The current size is higher than the requested size....


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