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Re: memory usage of code compiled with gcc 3.2
- From: LLeweLLyn Reese <llewelly at lifesupport dot shutdown dot com>
- To: hektor monteiro x285 <hmonteiro at ctio dot noao dot edu>
- Cc: gcc-help at gcc dot gnu dot org
- Date: 27 Dec 2002 20:04:31 -0800
- Subject: Re: memory usage of code compiled with gcc 3.2
- References: <3E0C5B7F.9090503@ctio.noao.edu>
hektor monteiro x285 <hmonteiro@ctio.noao.edu> writes:
> Hi everyone! I am working with an astrophysical code that uses a lot
> of memory (RAM). Basically because of a 3D matrix that I have to
> define. I was working with 1G of RAM before and could run the code
> with a cube of 70^3 cells. Recently I bought a new super machine with
> 4g of RAM and I am using the gcc 3.2 compiler on linux redhat 7.3. But
> I am not able to run more than 70^3 cells on this. Can anyone give me
> some clue?? I would think I should be able to do better no? Is this a
> linux kernel limitation or gcc or something else??
by default, linux kernels are built to address a max of 2G. If you
rebuild your kernel, you can change this options to allow 4G or
70T (virtual, not physical). I think this still leaves individual
processes limited to 2G, but at least other programs running at
the same time will not be biting into that.