NAME

       sched_setparam, sched_getparam - set and get scheduling parameters

SYNOPSIS

       #include <sched.h>

       int sched_setparam(pid_t pid, const struct sched_param *param);

       int sched_getparam(pid_t pid, struct sched_param *param);

       struct sched_param {
           ...
           int sched_priority;
           ...
       };

DESCRIPTION

       sched_setparam()  sets  the  scheduling  parameters associated with the scheduling policy for the process
       identified by pid.  If  pid  is  zero,  then  the  parameters  of  the  calling  process  are  set.   The
       interpretation  of  the argument param depends on the scheduling policy of the process identified by pid.
       See sched_setscheduler(2) for a description of the scheduling policies supported under Linux.

       sched_getparam() retrieves the scheduling parameters for the process identified by pid.  If pid is  zero,
       then the parameters of the calling process are retrieved.

       sched_setparam()  checks  the  validity  of  param  for  the  scheduling policy of the thread.  The value
       param->sched_priority   must   lie   within   the   range   given   by   sched_get_priority_min(2)    and
       sched_get_priority_max(2).

       For  a  discussion  of  the privileges and resource limits related to scheduling priority and policy, see
       sched_setscheduler(2).

       POSIX   systems   on   which    sched_setparam()    and    sched_getparam()    are    available    define
       _POSIX_PRIORITY_SCHEDULING in <unistd.h>.

RETURN VALUE

       On  success,  sched_setparam() and sched_getparam() return 0.  On error, -1 is returned, and errno is set
       appropriately.

ERRORS

       EINVAL The argument param does not make sense for the current scheduling policy.

       EPERM  The calling process does not have appropriate privileges (Linux: does not  have  the  CAP_SYS_NICE
              capability).

       ESRCH  The process whose ID is pid could not be found.

CONFORMING TO

       POSIX.1-2001.

NOTES

       Scheduling parameters are in fact per-thread attributes on Linux; see sched_setscheduler(2).

SEE ALSO

       getpriority(2), nice(2), sched_get_priority_max(2), sched_get_priority_min(2), sched_getaffinity(2),
       sched_getscheduler(2), sched_setaffinity(2), sched_setscheduler(2), setpriority(2), capabilities(7)

       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 3.54 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/.