sched_setscheduler() gives errno EPERM

Mats Lindbeg mats.w.lindberg at
Wed Feb 16 22:13:14 UTC 2011

I have a small program that simply changes the scheduling policy to SCHED_RR with sched_setscheduler and then exec's into another program. This worked fine in FBSD 5.x and 6.x. Now when I'm migrating to 8.1 I get EPERM from the the setscheduler call.
I have learned that If I start the same program with 'rtprio' it is allowed to change the scheduler. Strange to me - since I have always run it as root. What is the policy in 8.1?? Can this behavior be circumvented somehow? Some sysctl?

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