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 appropri-
       ately.

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

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

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 pro-
       cesses 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 per-
       formance.

       sched_yield() is intended for use with read-time scheduling policies (i.e., SCHED_FIFO  or
       SCHED_RR).   Use  of  sched_yield()  with  nondeterministic  scheduling  policies  such as
       SCHED_OTHER is unspecified and very likely means your application design is broken.

SEE ALSO
       sched(7)

COLOPHON
       This page is part of release 4.15 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at https://www.kernel.org/doc/man-pages/.

Linux                                       2017-09-15                             SCHED_YIELD(2)