Would be neat if randomized brk and setrlimit(RLIMIT_DATA, ...)
worked in a predictable way:

$ gcc brk.c -fPIC -pie -m64;./a.out;./a.out;./a.out
sbrk=0x7f721b815000 main=0x7f721af04860
sbrk succeeded (brk=0x7f721b909240)
sbrk=0x7fc3d77e2000 main=0x7fc3d66fa860
sbrk failed: Cannot allocate memory (brk=0x7fc3d77e2000)
sbrk=0x7f05b0615000 main=0x7f05af76b860
sbrk failed: Cannot allocate memory (brk=0x7f05b0615000)

-- 
Do what you love because life is too short for anything else.