RR_GET_INTERVAL

sched_rr_get_interval ? get the SCHED_RR interval for the named process

#include <sched.h>

int sched_rr_get_interval(pid_t pid, struct timespec *tp);

struct timespec {

time_t

tv_sec;

/* seconds */

long

tv_nsec;

/* nanoseconds */

};

sched_rr_get_interval writes into the timespec structure pointed to by tp the round robin time quantum for the process identified by pid. If pid is zero, the time quantum for the calling process is written into *tp. The identified process should be running under the SCHED_RR scheduling policy.

The round robin time quantum value is not alterable under Linux 1.3.81.

POSIX systems on which sched_rr_get_interval is available define _POSIX_PRIORITY_SCHEDULING in <unistd.h>.

On success, sched_rr_get_interval returns 0. On error, ?1 is returned, and errno is set appropriately.

ESRCH

The process whose ID is pid could not be found.

ENOSYS

The system call is not yet implemented.

POSIX.1b (formerly POSIX.4)

As of Linux 1.3.81 sched_rr_get_interval returns with error ENOSYS, because SCHED_RR has not yet been fully implemented and tested properly.

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, formerly POSIX.4)
ISO/IEC 9945-1:1996