Add rudimentary man pages for kernel options sched_4bsd and sched_ule,

which document some of the sysctls available for configuring 4bsd, some
of the bullet features of ule, and that ule is considered experimental
still.

MFC after:	3 days

1 files changed, 83 insertions, 0 deletions

diff --git a/share/man/man4/sched_ule.4 b/share/man/man4/sched_ule.4
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+.\" Copyright (c) 2005 Robert N. M. Watson
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd April 7, 2005
+.Os
+.Dt SCHED_ULE 4
+.Sh NAME
+.Nm sched_ule
+.Nd ULE Scheduler
+.Sh SYNOPSIS
+.Cd "options SCHED_ULE"
+.Sh DESCRIPTION
+.Nm
+is an experimental scheduler that provides a number of advanced scheduler
+features not present in
+.Xr sched_4bsd 4 ,
+the default system scheduler.
+These features address SMP and interactivity and include:
+.Pp
+.Bl -bullet -compact -offset indent
+.It
+Thread CPU affinity.
+.It
+CPU topology awareness, including for hyper-threading.
+.It
+Per-CPU run queues.
+.It
+Interactivity heuristics that detect interactive applications and schedules
+them preferentially under high load.
+.El
+.Pp
+The following sysctls are relevant to the operation of
+.Nm :
+.Bl -tag -width indent
+.It kern.sched.name
+This read-only sysctl reports the name of the active scheduler.
+.El
+.Pp
+.Nm
+is disabled by default as it is experimental.
+See the bugs section for more information.
+.Sh SEE ALSO
+.Xr sched_4bsd 4 ,
+.Xr sysctl 8
+.Sh HISTORY
+The
+.Nm
+scheduler first appeared in
+.Fx 5.1 .
+.Sh AUTHORS
+.An Jeff Roberson
+.Aq jeff@FreeBSD.org
+.Sh BUGS
+As an experimental scheduler,
+.Nm
+is not enabled by default due to a number of known issues, including weak
+performance with several known workloads, and reports of instability.
+Deployment of
+.Nm
+in production environments should be done cautiously.