how to forbid a process to use swap?

[Mehmet Erol Sanliturk]

On Sat, Mar 9, 2013 at 3:55 PM, Anton Shterenlikht <mexas at bristol.ac.uk>wrote:

> I run a program that uses large arrays.
> I don't want it to use swap, because it's
> too slow. I want the program to fail when
> there's not enough RAM, rather than using
> swap. How to do this?
>
> Is it something to do with these kernel
> variables:
>
> kern.dfldsiz: 34359738368
> kern.dflssiz: 8388608
>
> kern.maxdsiz: 34359738368
> kern.maxssiz: 536870912
> kern.maxtsiz: 134217728
>
> Many thanks
>
> Anton
>



If you have program source , you may do the following :



Define a constant :  Maximum_Allocatable_Memory = ?


Define a variable : Total_Allocated_Memory = 0



Before allocating a memory of size M ,
check whether  Total_Allocated_Memory + M < Maximum_Allocatable_Memory

If yes : Allocate memory ;
          Add M to Total_Allocated_Memory .

If no :

Return an error and gracefully stop your program instead of a crash which
will loose data .


Thank you very much .

Mehmet Erol Sanliturk