On Thu, Dec 2, 2010 at 12:51 PM, Andrew Duane <[email protected]> wrote: > > I've been poking at some bugs we have around pushing user memory to/past the > limits of our box, and decided to try seeing what happens on a stock FreeBSD > system (7.1 in this case). > > Basically I have a program that mallocs big memory chunks and zeros them to > consume both physical and virtual memory. I had expected the program to stop > malloc'ing when brk() reaches the process' RLIMIT_DATA (512MB cur and max). > It didn't. It happily malloc'd many gigabytes of memory until I stopped it. > > On our 6.2 based product boxes, RLIMIT_DATA correctly stops the malloc from > continuing, just like the manuals say. > > Am I missing something?
Starting on FreeBSD 7, the default malloc(3) implementation uses mmap(2), not brk(2) to manage its address space. There are two ways to deal with this: 1) edit /etc/malloc.conf and add the 'D' option to force malloc to use sbrk(2). I haven't tried this one. 2) limit the total virtual memory allowed by a process, RLIMIT_VMEM. This is what we used when migrating from FreeBSD 6 to 7. Cheers, matthew _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
