sched_rr_get_interval(2) get scheduling parameter limits

Other Alias

sched_get_priority_max, sched_get_priority_min

LIBRARY

Lb libc

SYNOPSIS

In sched.h Ft int Fn sched_get_priority_max int policy Ft int Fn sched_get_priority_min int policy Ft int Fn sched_rr_get_interval pid_t pid struct timespec *interval

DESCRIPTION

The Fn sched_get_priority_max and Fn sched_get_priority_min system calls return the appropriate maximum or minimum, respectively, for the scheduling policy specified by Fa policy . The Fn 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 Fn sched_get_priority_max and Fn 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 Fn sched_get_priority_max , Fn sched_get_priority_min , and Fn 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 .

STANDARDS

The Fn sched_get_priority_max , Fn sched_get_priority_min , and Fn sched_rr_get_interval system calls conform to St -p1003.1b-93 .