job termination: lack of memory. 32bit vs. 64bit problem?

Total energy, geometry optimization, DFT+U, spin....

Moderator: bguster

Locked
spamrefuse
Posts: 35
Joined: Wed Jan 20, 2010 3:08 am

job termination: lack of memory. 32bit vs. 64bit problem?

Post by spamrefuse » Tue Sep 28, 2010 2:57 pm

Hi,

Abinit 6.2.3 runs on a up-to-date Fedora system
(32 bits and with kernel 2.6.32-PAE).
The system has 6 GB RAM and 12 GB swap.

When I run the abinit job, it terminates because it cannot allocate
2779.477 Mb (see below for snippet from the log file).

How come this job cannot find 2779.477 MB (= 2.7 GB) ?

The 'top' command tells me that 90 % of the swap is not used
and 2 GB of RAM is free.

Am I facing here the limitation of a 32 bits version of the Linux OS?
If I replace the 32bits OS with its equivalent 64 bits version,
would that help?

My PC has an Intel Core i7 CPU, which effectively shows as 8 CPUs.
Would parallelization with mpi on the localhost do any good to solve
this memory problem?

Thank you!
Rob.


Here is the snippet of the log file:

[...snip...]
=========================================================
P This job should need less than 2779.477 Mbytes of memory.
Rough estimation (10% accuracy) of disk space for files :
WF disk file : -1573.915 Mbytes ; DEN or POT disk file : 9.613 Mbytes.
=========================================================

Biggest array : f_fftgr(disk), with 9.6128 MBytes.
memana : allocated an array of 9.613 Mbytes, for testing purposes.

memana : ERROR -
Test failed to allocate 2779.477 Mbytes
It is not worth to continue
Action : modify input variable to fit the available memory.
or increase limit on available memory.

leave_new : decision taken to exit ...
=========================================================

mverstra
Posts: 655
Joined: Wed Aug 19, 2009 12:01 pm

Re: job termination: lack of memory. 32bit vs. 64bit problem

Post by mverstra » Mon Oct 11, 2010 11:52 am

Please do not post the same questions to several different sub-forums

viewtopic.php?f=2&t=622&p=1795&hilit=2779#p1795
Matthieu Verstraete
University of Liege, Belgium

Locked