[Octopus-users] inherent memory limits?

[Emily]

I figured out my problem.  I compiled it a long time ago, so perhaps I
have some excuse for forgetting that I compiled it on a 32-bit machine.

 file octopus 
octopus: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for
GNU/Linux 2.2.5, dynamically linked (uses shared libs), not stripped

To use more than a few GB of memory it needs to be compiled on a 64-bit
machine and I've also been advised to use the -mcmodel=medium flag.  

Of course, now that I'm going to compile it again anyway, I will compile
it with parallel support, so won't need as much memory on any given node
(at least so I think?).  

----- Original message -----
From: "Emily" <listemily at eml.cc>
To: "octopus users group" <octopus-users at tddft.org>
Date: Fri, 18 Dec 2009 17:03:00 -0500
Subject: inherent memory limits?

Hello,

I'm trying to run a simulation that takes a lot of memory, on a computer
that has even more memory, and it's failing. 

Specifically, I'm getting an error:

**************************** FATAL ERROR *****************************
*** Fatal Error (description follows)
*--------------------------------------------------------------------
* Failed to allocate     122581 Kb in file 'td_rti.F90' line   287
*--------------------------------------------------------------------
* Stack:
**********************************************************************

But the node I'm running on has 32 Gb of memory, and I get this error
after the code has buffered just over 6 Gb of memory, and used 2.25 Gb,
at the beginning of the time dependent calculation.

I'm wondering if there is some inherent limit in the code that would
cause this error even if I have plenty of memory available.  

My pbs submission script contains the lines:

#PBS -l nodes=1:emt64,pmem=32000mb,vmem=32000mb -W
x=NACCESSPOLICY:SINGLEJOB
#PBS -q hugemem
#PBS -j oe
limit stacksize unlimited

which I have reason to believe (but not certainty) are supposed to allow
me to use the 32 Gb.

Can anybody suggest reasons I can't access more memory?

Oh, and:
 Running octopus, version 2.1.0
              build time - Tue Dec  4 14:31:54 EST 2007
                            svn revision:

                           Compiler: ifort
Compiler flags: -u -zero -fpp1 -nbs -pc80 -pad -align -unroll -O3 -ip
-tpp7 -xW

Thanks,
Emily