The issue is a regression with PAE, reproduced and verified on Ubuntu, on my home PC with 3GB RAM. My PC was running kernel linux-image-3.2.0-35-generic so it showed: psz@DellE520:~$ uname -a Linux DellE520 3.2.0-35-generic #55-Ubuntu SMP Wed Dec 5 17:45:18 UTC 2012 i686 i686 i386 GNU/Linux psz@DellE520:~$ free -l total used free shared buffers cached Mem: 3087972 692256 2395716 0 18276 427116 Low: 861464 71372 790092 High: 2226508 620884 1605624 -/+ buffers/cache: 246864 2841108 Swap: 20000920 258364 19742556 Then it handled the "sleep test" bash -c 'n=0; while [ $n -lt 33000 ]; do sleep 600 & ((n=n+1)); ((m=n%500)); if [ $m -lt 1 ]; then echo -n "$n - "; date; free -l; sleep 1; fi; done' just fine, stopped only by "max user processes" (default setting of "ulimit -u 23964"), or raising that limit stopped when the machine ran out of PID space; there was no OOM. Installing and running the PAE kernel so it showed: psz@DellE520:~$ uname -a Linux DellE520 3.2.0-35-generic-pae #55-Ubuntu SMP Wed Dec 5 18:04:39 UTC 2012 i686 i686 i386 GNU/Linux psz@DellE520:~$ free -l total used free shared buffers cached Mem: 3087620 681188 2406432 0 167332 352296 Low: 865208 214080 651128 High: 2222412 467108 1755304 -/+ buffers/cache: 161560 2926060 Swap: 20000920 0 20000920 and re-trying the "sleep test", it ran into OOM after 18000 or so sleeps and crashed/froze so I had to press the POWER button to recover. Cheers, Paul Paul Szabo psz@xxxxxxxxxxxxxxxxx http://www.maths.usyd.edu.au/u/psz/ School of Mathematics and Statistics University of Sydney Australia -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>