linux man page for sched_yield

SCHED_YIELD(2)						     Linux Programmer's Manual						    SCHED_YIELD(2)

NAME
       sched_yield - yield the processor

SYNOPSIS
       #include <sched.h>

       int sched_yield(void);

DESCRIPTION
       sched_yield()  causes  the calling thread to relinquish the CPU.  The thread is moved to the end of the queue for its static priority and a
       new thread gets to run.

RETURN VALUE
       On success, sched_yield() returns 0.  On error, -1 is returned, and errno is set appropriately.

ERRORS
       In the Linux implementation, sched_yield() always succeeds.

CONFORMING TO
       POSIX.1-2001.

NOTES
       If the calling thread is the only thread in the highest priority list at that time, it will continue to run after a call to sched_yield().

       POSIX systems on which sched_yield() is available define _POSIX_PRIORITY_SCHEDULING in <unistd.h>.

       Strategic calls to sched_yield() can improve performance by giving other threads or processes a chance  to  run	when  (heavily)  contended
       resources  (e.g.,  mutexes)  have  been	released  by the caller.  Avoid calling sched_yield() unnecessarily or inappropriately (e.g., when
       resources needed by other schedulable threads are still held by the caller), since doing so will result in  unnecessary	context  switches,
       which will degrade system performance.

SEE ALSO
       sched_setscheduler(2) for a description of Linux scheduling.

       Programming for the real world - POSIX.4 by Bill O. Gallmeister, O'Reilly & Associates, Inc., ISBN 1-56592-074-0

COLOPHON
       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2008-10-18							    SCHED_YIELD(2)