Hi,

While playing on my amd64 workstation (2 Opterons 246, 1GB of Ram),
running NetBSD -current (20040614); i noticed that the system became
unresponsive for a few seconds with a small program that try to
allocate and initialize about 800MB. Looks similar to the previous
`pagedaemon' problem under low memory conditions recently fixed ...

The same test on an i386 machine does not exhibit this behaviour.

load averages:  1.78,  1.76,  1.07                                     14:03:08
52 processes:  51 sleeping, 1 on processor
CPU0 states:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
CPU1 states:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
Memory: 237M Act, 4312K Wired, 18M Exec, 218M File, 556M Free
Swap: 4096M Total, 24M Used, 4073M Free

njoly@lanfeust [~]> time ./maxmem
len = 838860800
ptr = 0x513000
 cool :]
./maxmem  0.00s user 0.01s system 51% cpu 0.019 total

njoly@lanfeust [~]> time MALLOC_OPTIONS=J ./maxmem
len = 838860800
ptr = 0x513000
 cool :]
MALLOC_OPTIONS=J ./maxmem  0.36s user 1.98s system 33% cpu 7.045 total

njoly@lanfeust [~]> cat maxmem.c
#include<stdio.h>
#include<stdlib.h>

int main() {
  char *p;
  size_t len;

  len = 800 * 1024 * 1024;
  printf("len = %lu\n", len);

  p = malloc(len);
  if (p == NULL) {
    printf("ARGH :[\n");
    exit(1); }
  printf("ptr = %p\n", p);
  printf(" cool :]\n");

  exit(0); }

Thanks in advance,
Regards.

-- 
Nicolas Joly

Biological Software and Databanks.
Institut Pasteur, Paris.