---
name: "sched_ule"
section: "4freebsd"
platform: "linux"
package: "freebsd-manpages"
version: "12.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/sched_ule/4freebsd"
---

# sched\_ule(4freebsd)

ULE scheduler

## NAME

**sched\_ule** – ULE scheduler

## SYNOPSIS

**options SCHED\_ULE**

## DESCRIPTION

The **sched\_ule** scheduler provides a number of advanced scheduler features not present in [sched\_4bsd(4)](/sched_4bsd/4.md), 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 **sched\_ule**:

- *kern.sched.name*

  This read-only sysctl reports the name of the active scheduler.

- *kern.sched.quantum*

  This read-write sysctl reports or sets the length of the quantum (in micro-seconds) granted to a thread.

## SEE ALSO

[sched\_4bsd(4)](/sched_4bsd/4.md), [sysctl(8)](/sysctl/8.md)

## HISTORY

The **sched\_ule** scheduler first appeared in FreeBSD 5.1.

## AUTHORS

Jeff Roberson ⟨*jeff@FreeBSD.org*⟩