centos man page for yield_to

YIELD_TO(9)							   Driver Basics						       YIELD_TO(9)

NAME
       yield_to - yield the current processor to another thread in your thread group, or accelerate that thread toward the processor it's on.

SYNOPSIS
       bool __sched yield_to(struct task_struct * p, bool preempt);

ARGUMENTS
       p
	   target task

       preempt
	   whether task preemption is allowed or not

DESCRIPTION
       It's the caller's job to ensure that the target task struct can't go away on us before we can do any checks.

RETURN
       true (>0) if we indeed boosted the target task. false (0) if we failed to boost the target. -ESRCH if there's no task to yield to.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							       YIELD_TO(9)