SCHED_SETPARAM (2)
set and get scheduling parameters
SYNOPSIS
#include <sched.h>
int sched_setparam(pid_t pid, const struct sched_param *p);
int sched_getparam(pid_t pid, struct sched_param *p);
4n
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 current process are set. The interpretation of
the parameter p depends on the selected policy. Currently, the
following three scheduling policies are supported under Linux:
SCHED_FIFO ,
SCHED_RR ,
and
SCHED_OTHER.
sched_getparam
retrieves the scheduling parameters for the
process identified by pid. If pid is zero, then the parameters
of the current process are retrieved.
sched_setparam
checks the validity of p for the scheduling policy of the
process. The parameter p->sched_priority must lie within the
range given by sched_get_priority_min and
sched_get_priority_max.
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,
errno
is set appropriately.
ERRORS
ESRCH
The process whose ID is pid could not be found.
EPERM
The calling process does not have appropriate privileges. The process
calling
sched_setparam
needs an effective uid equal to the euid or uid of the process
identified by
pid ,
or it must be a superuser process.
EINVAL
The parameter p does not make sense for the current
scheduling policy.
CONFORMING TO
POSIX.1b (formerly POSIX.4)
SEE ALSO
sched_setscheduler(2) sched_getscheduler(2) sched_get_priority_max(2) sched_get_priority_min(2) - nice (2) -
setpriority(2) - getpriority (2) -
sched_setscheduler(2) has a description of the Linux scheduling scheme Programming for the real world - POSIX 4 by Bill O Gallmeister O'Reilly & Associates Inc ISBN 1-56592-074-0 IEEE Std 1003 1b-1993 (POSIX 1b standard) ISO/IEC 9945-1:1996
|
|
