sched_getparam(2)

NAME
     sched_getparam - get the scheduling parameters of a process

C SYNOPSIS
     #include <sched.h>
     int sched_getparam (pid_t pid, const struct sched_param *param);

DESCRIPTION
     The sched_getparam system call is used to get the scheduling parameters
     for the process specified by pid.  If pid is set to zero, then the
     scheduling parameters of the calling process will be obtained.

     A process may obtain the scheduling parameters of itself and any process
     sharing the same real user ID [see getuid(2)].  To obtain the scheduling
     parameters of an unrelated process, the calling process must have
     superuser permissions.

     The scheduling parameters of pid are returned via the parameter structure
     at address param (see sched_setparam(2)).

     If pid refers to a POSIX thread process [see pthreads(3P)] then this call
     retrieves the scheduling policy parameters that are shared by process
     scope threads.

     sched_getparam will fail if one or more of the following are true:

     [EINVAL]       The process specified by pid is not executing with a
                    scheduling policy.

     [EFAULT]       The address specified by param is outside the range of the
                    address space of the calling process.

     [EPERM]        The calling process attempted to obtain the scheduling
                    parameters of an unrelated process and the caller does not
                    have superuser permissions.

     [ESRCH]        The process specified by pid does not exist.

SEE ALSO
     sched_getscheduler(2), sched_get_priority_max(2),
     sched_get_priority_min(2), sched_rr_get_interval(2), sched_setparam(2),
     sched_setscheduler(2), sched_yield(2), getuid(2), pthreads(5)

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned to the calling
     process. Otherwise, a value of -1 is returned and errno is set to
     indicate the error.