#include <sched.h>
int sched_setscheduler(pid_t pid, int policy, const struct sched_param * param);
int sched_setscheduler
The sched_setscheduler() shall behave as described in POSIX 1003.1-2008 (ISO/IEC 9945-2009), except as noted below.
On success, 0 is returned instead of the former scheduling policy.