xref: /freebsd/share/man/man4/sched_ule.4 (revision 4b9d6057)
1.\" Copyright (c) 2005 Robert N. M. Watson
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
25.Dd August 10, 2012
26.Dt SCHED_ULE 4
27.Os
28.Sh NAME
29.Nm sched_ule
30.Nd ULE scheduler
31.Sh SYNOPSIS
32.Cd "options SCHED_ULE"
33.Sh DESCRIPTION
34The
35.Nm
36scheduler
37provides a number of advanced scheduler
38features not present in
39.Xr sched_4bsd 4 ,
40the traditional system scheduler.
41These features address SMP and interactivity and include:
42.Pp
43.Bl -bullet -compact -offset indent
44.It
45Thread CPU affinity.
46.It
47CPU topology awareness, including for hyper-threading.
48.It
49Per-CPU run queues.
50.It
51Interactivity heuristics that detect interactive applications and schedules
52them preferentially under high load.
53.El
54.Pp
55The following sysctls are relevant to the operation of
56.Nm :
57.Bl -tag -width indent
58.It Va kern.sched.name
59This read-only sysctl reports the name of the active scheduler.
60.It Va kern.sched.quantum
61This read-write sysctl reports or sets the length of the quantum (in
62micro-seconds) granted to a thread.
63.El
64.Sh SEE ALSO
65.Xr sched_4bsd 4 ,
66.Xr sysctl 8
67.Sh HISTORY
68The
69.Nm
70scheduler first appeared in
71.Fx 5.1 .
72.Sh AUTHORS
73.An Jeff Roberson Aq Mt jeff@FreeBSD.org
74