Re: modifying heap available to a process

On Mon, 8 Dec 2003 19:34:02 -0800 (PST), exits funnel wrote:

> Hello,
> 
> I'm pretty new to Linux and I'm trying to figure out
> how to modify the amount of heap available to a
> process.  I have the following simple C++ program:
> 
> //START CODE
> #include <iostream>
> #include <cstdlib>
> #include <new>
> using namespace std;
> int count = 0;
> void out_of_memory( )
> {
>   cerr << "memory exhausted after " << count << "
> allocations!" << endl;
>   cerr << "or " << count * 10000 * sizeof(int) << "
> bytes" << endl;
>   exit(1);
> }
> 
> int main( )
> {
>   set_new_handler(out_of_memory);
>   while(1)
>   {
>     count++;
>     new int[10000];
>   }
> }
> //END CODE
> 
> When I run this program the output is:
> 
> memory exhausted after 76677 allocations!
> or 3067080000 bytes
> 
> I would like to limit the heap available to the
> process.  I think ulimit should be able to do what I
> want but I've not had any luck yet.  (As an aside is
> their any documentation available for the bash
> builtins anywhere?)

man ulimit
man bash

> If I issue 'ulimit -m 2' and then
> 'ulimit -a' it seems to indicate that max memory has
> been set to 2k but when I run the program again I get
> the same output.  So, can anyone tell me how to limit
> the heap available to a process?  Thanks in advance
> for any replies!

Limit the virtual memory, option -v.