centos man page for yield

YIELD(9)							   Driver Basics							  YIELD(9)

NAME
       yield - yield the current processor to other threads.

SYNOPSIS
       void __sched yield(void);

ARGUMENTS
       void
	   no arguments

DESCRIPTION
       Do not ever use this function, there's a 99% chance you're doing it wrong.

       The scheduler is at all times free to pick the calling task as the most eligible task to run, if removing the yield call from your code
       breaks it, its already broken.

TYPICAL BROKEN USAGE IS
       while (!event) yield;

       where one assumes that yield will let 'the other' process run that will make event true. If the current task is a SCHED_FIFO task that will
       never happen. Never use yield as a progress guarantee!!

       If you want to use yield to wait for something, use wait_event. If you want to use yield to be 'nice' for others, use cond_resched. If you
       still want to use yield, do not!

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014								  YIELD(9)