From owner-freebsd-questions  Thu Aug 12  9:11:26 1999
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From: Charles Randall <crandall@matchlogic.com>
To: Alec Kalinin <alec@relex.ru>
Cc: freebsd-questions@freebsd.org
Subject: RE: Problem with allocation memory in FreeBSD-3.2-RELEASE
Date: Thu, 12 Aug 1999 10:09:13 -0600
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Looks like you're simply running the system out of swap by allocating and
touching 1 MB one thousand times for a total of 1 GB.

Malloc will eventually return NULL to indicate the system is out of memory.
Since you don't check for this, I'd expect a core dump when malloc returns
NULL and then you try to fill with zeros.

What did you expect to happen?

Charles

-----Original Message-----
From: Alec Kalinin [mailto:alec@relex.ru]
Sent: Thursday, August 12, 1999 4:18 AM
To: freebsd-questions@freebsd.org
Subject: Problem with allocation memory in FreeBSD-3.2-RELEASE


Hello!

I have a problem with allocation memory in FreeBSD-3.2-RELEASE. This simple
program hungs my system:

------------------- begin program -----------------------------
#include <unistd.h>
#include <stdlib.h>

#define NALLOC          1000
#define SIZEALLOC       1024*1024
#define WAIT            100

void main()
{
 char *p_mem;
 int i, j;

 if (fork() != 0) return;

 for (i=0; i<NALLOC; i++) {
//     usleep(WAIT);
     p_mem = (char *)malloc(SIZEALLOC);
     for (j=0; j<SIZEALLOC; j++) {
         p_mem[j] = 0;
     }
 }

 while (1);
}
------------------- begin program -----------------------------

I have a swap space about 100 M. After run this program, i can't write
something to my consoles -- system like hang system. But it answer for ping.
It may be my problem, but it may be kernel problem ;)


P.S. My English is not as well, as i want. If you have troubles with read my
letter, sorry.

Good luck,
            Alec



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