Re: coping with swap-exhaustion in 2.4.33-4

[Yakov Lerner]

On 11/23/06, Xavier Bestel <xavier.bestel@xxxxxxx> wrote:
> On Thu, 2006-11-23 at 14:30 +0200, Yakov Lerner wrote:
> >     Where can I read anything about how kernel is supposed to
> > react to the 'swap-full' condition ? We have troubles on the
> > production machine which routinely arrives to the swap-full state
> > no matter how I increase the swap, because user proceses multi-fork
> > and then want to allocate a lot of virtual memory.
>
> Did you disable memory overcommit ?

The /proc/sys/vm/overcommit_memory is 0 (the default is 0, no ?)

This is test program, memstress.c. We make sure we touch all allocated chunks.

#include <stdio.h>
#include <stdlib.h>
#include <poll.h>
#include <string.h>


int main(int argc, char **argv) {
   char *p;
   int size = 10*1024*1024;
   int k;
   int bypass_prompt = 0;
   int mb = 0;
   int bytes = 0;

   printf("Warning this allocation test may kill your computer by
exhausting the swap+memory\n");
   if( argc > 1 && 0 == strcmp("-f", argv[1])) {
       bypass_prompt = 1;
   }
   if(!bypass_prompt) {
       printf("Press Enter to proceed, or Ctrl-C to cancel; or use -f
option to bypass the prompt\n");
       getchar();
   }


   for(k=0; ; k++)  {
       p = malloc(size);
       if(p) {
           memset(p, 0xff, size );
           bytes += size;
           printf("%d mb\n", bytes / (1024*1024) );
       }
       poll(0,0, 1);
   }
}
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