Yolinux.com

SCHED_YIELD manpage

Search topic Section


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.

SEE ALSO
       sched(7)

COLOPHON
       This page is part of release 4.10 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				  2015-08-08			SCHED_YIELD(2)