Can some throw bright light on Linux Memory Allocation

[Chris Jones]

MirJafar Aki wrote:
> Hello,
> 
> I have installed Ubuntu on a machine with following
> config.
> 
> RAM :  2 GB
> Machine:  Intel Core 2 Duo
> OS:  Ubuntu 64 bit.
> Disk:  250 GB.
> 
> 
> I have attached a simple program to test memory allocation on linux and 
> something strange is happening.
> 
> 1.    If I invoke large_memory function then maximum
>        size I am allowed is 245GB.
>  
> 2.    If I use less than 245GB  ( say 244 GB) then the
>        second stage is also passed.  Where from OS is
>        allocating 244GB ?

Maybe I'm missing the point here, but why on Earth would you want to try 
and allocate 250G of memory on a machine with 'only' 2G ram. Is your 
250G disk entirely devoted to swap space ??

Chris