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.\" $FreeBSD$ 26.\" 27.Dd April 7, 2005 28.Os 29.Dt SCHED_ULE 4 30.Sh NAME 31.Nm sched_ule 32.Nd ULE scheduler 33.Sh SYNOPSIS 34.Cd "options SCHED_ULE" 35.Sh DESCRIPTION 36The 37.Nm 38scheduler 39is an experimental scheduler that provides a number of advanced scheduler 40features not present in 41.Xr sched_4bsd 4 , 42the default system scheduler. 43These features address SMP and interactivity and include: 44.Pp 45.Bl -bullet -compact -offset indent 46.It 47Thread CPU affinity. 48.It 49CPU topology awareness, including for hyper-threading. 50.It 51Per-CPU run queues. 52.It 53Interactivity heuristics that detect interactive applications and schedules 54them preferentially under high load. 55.El 56.Pp 57The following sysctls are relevant to the operation of 58.Nm : 59.Bl -tag -width indent 60.It Va kern.sched.name 61This read-only sysctl reports the name of the active scheduler. 62.El 63.Pp 64The 65.Nm 66scheduler 67is disabled by default as it is experimental. 68See the 69.Sx BUGS 70section for more information. 71.Sh SEE ALSO 72.Xr sched_4bsd 4 , 73.Xr sched_core 4 , 74.Xr sysctl 8 75.Sh HISTORY 76The 77.Nm 78scheduler first appeared in 79.Fx 5.1 . 80.Sh AUTHORS 81.An Jeff Roberson 82.Aq jeff@FreeBSD.org 83.Sh BUGS 84As an experimental scheduler, 85.Nm 86is not enabled by default due to a number of known issues, including weak 87performance with several known workloads, and reports of instability. 88Deployment of 89.Nm 90in production environments is not recommended at this time. 91