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, 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_PRIOR-
       ITY_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.

       sched_yield() is intended for use with  read-time  scheduling  policies
       (i.e., SCHED_FIFO or SCHED_RR).  Use of sched_yield() with nondetermin-
       istic 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)
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