Hi! I tried to mmap 16GB of memory (MAP_ANONYMOUS) for my program which runs on amd64 ubuntu jaunty. However as long as I mmap more that 8GB, it fails with ENOMEM if ((buf = mmap(NULL, (size_t)1024 * 1024 * 1024 * 16, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0)) == MAP_FAILED) { perror("mmap()"); abort(); } The machine happens to have 4GB of physical memory installed but ulimit shows no limit on max memory: $ ulimit -a core file size (blocks, -c) 100000 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 38912 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 38912 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited What is the limit of MAP_ANONYMOUS? Can we increase the limit? Thanks! Mark -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ