idle is an internal system call used during bootstrap.
It marks the process's pages as swappable, lowers its priority,
and enters the main scheduling loop.
idle never returns.
Only process 0 may call
idle . Any user process, even a process with super-user permission,
will receive
EPERM .
RETURN VALUE
idle never returns for process 0, and always returns -1 for a user process.
ERRORS
EPERM
Always, for a user process.
CONFORMING TO
This function is Linux-specific, and should not be used in programs
intended to be portable.
NOTES
Since 2.3.13 this system call does not exist anymore.
