[svlug] Max process size

[Seth David Schoen]

Marc MERLIN writes:

> On dim, mai 21, 2000 at 01:26:10 -0700, Wayne Earl wrote:
> > Hello all!
> > 
> > Can anyone tell me what is the maximum processess size under linux, and if
> 
> I believe it's 1 or 2G on IA32 depending on how your kernel was compiled. I
> don't remember whether BIGMEM allows you to have more or not.
> (you said "under linux", it really depends on the architecture)
> 
> > there is a way to increase this number? I can't find anything in the
> > kernel source that would indicate a maximum. (this server runs 2.2.12,
> > single processor)
> > 
> > The machine in question has 1GB of RAM, and it appears that processes
> > won't go over 256MB in size. (data gathered by running top).
> 
> Mmmh, you much have some other problem:
> obelix.valinux.com >cat malloc.c 
> #include <malloc.h>
> 
> int main()
> {
>     int i;
>     char *ptr;
> 
>     system("free");
> 
>     ptr=malloc(512*1048576);
>     printf("\nPointer: %ld\n\n", ptr);
> 
>     for (i=0;i<512*1048576;i++)
>     {
>         *(ptr+i)=1;
>     }

It might be faster to

memset(ptr, 1, 512*1048576)

depending on how the compiler optimizes that loop.

-- 
Seth David Schoen <schoen at loyalty.org>  | And do not say, I will study when I
Temp.  http://www.loyalty.org/~schoen/  | have leisure; for perhaps you will
down:  http://www.loyalty.org/   (CAF)  | not have leisure.  -- Pirke Avot 2:5