sched_setparam, sched_getparam - set and get scheduling parameters
Standard C library (libc, -lc)
#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;
...
};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>.
On success, sched_setparam() and
sched_getparam() return 0. On error, -1 is returned,
and errno is set to indicate the error.
Invalid arguments: param is NULL or pid is
negative
(sched_setparam()) The argument param does
not make sense for the current scheduling policy.
(sched_setparam()) The caller does not have appropriate privileges (Linux: does not have the CAP_SYS_NICE capability).
The thread whose ID is pid could not be found.
POSIX.1-2024.
POSIX.1-2001.
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)