How do I use the memory lock facility in LInux

[dayaking]

Hi,

I am trying to run a program [ Modelsim ] on a 64 bit linux HP
machine. May be bacause of the size of the program, the testcase comes
out with the following Error.
============ ========= ==
# Fatal: (vsim-4) ** Memory allocation failure. **
# Pelase check your system for avialable memory and swap space.
============ ========= ==


The possible solutions suggested for this are
1. Use the memory locking feature on HP-UX or the memory sharing
feature on Solaris
2. Increase the size of swap space
3, Add memory to your machine and others..

Could any one please let me know how to use the memory locking feature
in HP Linux machine.

I understand that we need to re-work with partition of hard-disk etc
for making changes in the swap space. Is there an alternate way to do
this other than working with partition of the disk ?

Thanks in advance,
Dayananda

 

[Neil Dugan]

Hi,

I am trying to run a program [ Modelsim ] on a 64 bit linux HP
machine. May be bacause of the size of the program, the testcase comes
out with the following Error.
============ ========= ==
# Fatal: (vsim-4) ** Memory allocation failure. **
# Pelase check your system for avialable memory and swap space.
============ ========= ==


The possible solutions suggested for this are
1. Use the memory locking feature on HP-UX or the memory sharing
feature on Solaris
2. Increase the size of swap space
3, Add memory to your machine and others..

Could any one please let me know how to use the memory locking feature
in HP Linux machine.

I understand that we need to re-work with partition of hard-disk etc
for making changes in the swap space. Is there an alternate way to do
this other than working with partition of the disk ?

Thanks in advance,
Dayananda

You can extend the swap space by creating and using a big file for the
swap space. If you use a file, it can be generated when needed and
deleted when done. It will be slower, but should fix your memory
problems.

see
http://www.redhat.com/docs/manuals/linux/RHL-8.0-Manual/custom-guide/s1-swap-adding.html

These instructions are aimed at Red Hat Linux but it is a generic
problem and should work on almost any Linux installation.


Regards Neil.

 

[Paul Uiterlinden]

Hi,

I am trying to run a program [ Modelsim ] on a 64 bit linux HP
machine. May be bacause of the size of the program, the testcase comes
out with the following Error.
============ ========= ==
# Fatal: (vsim-4) ** Memory allocation failure. **
# Pelase check your system for avialable memory and swap space.
============ ========= ==


The possible solutions suggested for this are
1. Use the memory locking feature on HP-UX or the memory sharing
feature on Solaris
2. Increase the size of swap space
3, Add memory to your machine and others..

But the most important solution is missing here!

0. Find out why you're simulation needs so much memory.

Does it immediately eat all the memory, as does it happen during simulation?

If it is the first case, have you modeled some kind of memory model for your
simulation? If so, does it use an array of signals to model the memory
core? If that is the case, rewrite this model so it uses a variable in
stead of a signal. Signals take about 10X more memory on your machine than
variables do. If it already is a variable, but it is too large, you need to
model it as a sparse memory.

You could try to load part of the design/testbench to try to locate the
culprit.

Of course there are more possibilities, such as forgetting to use deallocate
for dynamically allocated data (via access types). This would eat memory
during simulation.

To say anything sensible, more information is needed. What exactly is it
that you are trying to simulate? What kind of models are involved? And how
much RAM does your workstation have anyway?