For what it's worth, in the Linux kernel brk() just calls mmap() to grow the bss segment. So under the hood, just about everything is mmap(), and brk() is shor

For what it's worth, in the Linux kernel brk() just calls mmap() to grow the bss segment. So under the hood, just about everything is mmap(), and brk() is shorthand for a mmap() call that operates on a well known pre-existing mmap() area.