Issue

• Revision 0.2-80 of “Red Hat Enterprise Linux 7 Migration Planning Guide” in section 2.2.3.1 it states the following. I’m unable to find any information about this limitation on the internet and upstream documentation does not list this same limitation.

  SysV services, even those with root privileges, are no longer permitted to acquire realtime scheduling.
  

• 3rd party services trying to acquire realtime scheduling fail to start, strace on the service executable shows a EPERM (Operation not permitted) error when calling the sched_setscheduler syscall with SCHED_RR parameter:

  # strace <program> 2>&1 >/dev/null | grep sched_setscheduler
  sched_setscheduler(0, SCHED_RR, { 99 }) = -1 EPERM (Operation not permitted)