[$] kcmp() breaks loose
Given the large set of system calls implemented by the Linux kernel, it
would not be surprising for most people to be unfamiliar with a few of
them. Not everybody needs to know the details of
setresgid(),
modify_ldt(),
or
lookup_dcookie(),
after all. But even developers who have a wide understanding of the Linux
system-call set may be surprised by kcmp(),
which is not enabled by default in the kernel build. It would seem,
though, that the word has gotten out, leading to an effort to make
kcmp() more widely available.