sched_get_priority_maxsched_get_priority_minsched_rr_get_interval
- get scheduling parameter limits
LIBRARY
Lb libc
SYNOPSIS
#include <sched.h> int
sched_get_priority_max (int policy); int
sched_get_priority_min (int policy); int
sched_rr_get_interval (pid_t pid struct timespec *interval);
DESCRIPTION
The
sched_get_priority_max ();
and
sched_get_priority_min ();
system calls return the appropriate maximum or minimum, respectively,
for the scheduling policy specified by
Fa policy .
The
sched_rr_get_interval ();
system call updates the
Fa timespec
structure referenced by the
Fa interval
argument to contain the current execution time limit (i.e., time
quantum) for the process specified by
Fa pid .
If
Fa pid
is zero, the current execution time limit for the calling process is
returned.
The value of
Fa policy
should be one of the scheduling policy values defined in
Fa <sched.h> :
Bq Er SCHED_FIFO
First-in-first-out fixed priority scheduling with no round robin scheduling;
Bq Er SCHED_OTHER
The standard time sharing scheduler;
Bq Er SCHED_RR
Round-robin scheduling across same priority processes.
RETURN VALUES
If successful, the
sched_get_priority_max ();
and
sched_get_priority_min ();
system calls shall return the appropriate maximum or minimum values,
respectively.
If unsuccessful, they shall return a value of -1 and set
Fa errno
to indicate the error.
Rv -std sched_rr_get_interval
ERRORS
On failure
errno
will be set to the corresponding value:
Bq Er EINVAL
The value of the
Fa policy
argument does not represent a defined scheduling policy.
Bq Er ENOSYS
The
sched_get_priority_max (,);
sched_get_priority_min (,);
and
sched_rr_get_interval ();
system calls are not supported by the implementation.
Bq Er ESRCH
No process can be found corresponding to that specified by
Fa pid .
