SCHED_SETPARAM
Section: Linux Programmer's Manual (2)
Updated: 2019-10-10
Page Index
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 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 appropriately.
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.
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
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)
COLOPHON
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