sched_ule(4) ULE scheduler


options SCHED_ULE


The scheduler provides a number of advanced scheduler features not present in sched_4bsd4, the traditional system scheduler. These features address SMP and interactivity and include:

  • Thread CPU affinity.
  • CPU topology awareness, including for hyper-threading.
  • Per-CPU run queues.
  • Interactivity heuristics that detect interactive applications and schedules them preferentially under high load.

The following sysctls are relevant to the operation of :
This read-only sysctl reports the name of the active scheduler.
This read-write sysctl reports or sets the length of the quantum (in micro-seconds) granted to a thread.


The scheduler first appeared in Fx 5.1 .


An Jeff Roberson Aq [email protected]