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 (heav-
       ily) 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 3.25 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)