is implemented using copy-on-write pages, so the only penalty that it incurs
is the time and memory required to duplicate the parent's page tables,
and to create a unique task structure for the child.
-.SS C library/kernel ABI differences
+.SS C library/kernel differences
Since version 2.3.3,
.\" nptl/sysdeps/unix/sysv/linux/fork.c
rather than invoking the kernel's