NAME

       sched_setparam, sched_getparam - set and get scheduling parameters

LIBRARY

       Standard C library (libc, -lc)

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 thread whose thread ID is specified in pid.  If pid is zero, then  the  parameters  of
       the  calling  thread  are  set.   The  interpretation of the argument param depends on the
       scheduling policy of the thread identified by pid.  See sched(7) for a description of  the
       scheduling policies supported under Linux.

       sched_getparam() retrieves the scheduling parameters for the thread identified by pid.  If
       pid is zero, then the parameters of the calling thread 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(7).

       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 to indicate the error.

ERRORS

       EINVAL Invalid arguments: param is NULL or pid is negative

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

       EPERM  (sched_setparam()) The caller does not have appropriate privileges (Linux: does not
              have the CAP_SYS_NICE capability).

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

STANDARDS

       POSIX.1-2008.

HISTORY

       POSIX.1-2001.

SEE ALSO

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