This is the host:
# free -m
             total       used       free     shared    buffers     cached
Mem:          7981       7933         47          0          0       5850
-/+ buffers/cache:       2083       5897
Swap:        22888          0      22888

Inside container (the only one running at this point):
# free -m
             total       used       free     shared    buffers     cached
Mem:           256         60        195          0          0          0

# cat /proc/user_beancounters | grep privv
            privvmpages                 15638               200464                73728                80362               486040

# sysctl -a | grep overcommit
vm.overcommit_memory = 0
vm.overcommit_ratio = 50
vm.nr_overcommit_hugepages = 0

# ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 71680
max locked memory       (kbytes, -l) 32
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) 71680
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited