diff options
author | rwatson <rwatson@FreeBSD.org> | 2005-04-07 21:57:19 +0000 |
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committer | rwatson <rwatson@FreeBSD.org> | 2005-04-07 21:57:19 +0000 |
commit | f7a82d65b001f4cddf500e45fcad54650963b926 (patch) | |
tree | 31bd052481128c278a997ad27949de2399880602 | |
parent | 986a072ce4b5a38b5add610206c1e35411075393 (diff) | |
download | FreeBSD-src-f7a82d65b001f4cddf500e45fcad54650963b926.zip FreeBSD-src-f7a82d65b001f4cddf500e45fcad54650963b926.tar.gz |
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
-rw-r--r-- | share/man/man4/Makefile | 2 | ||||
-rw-r--r-- | share/man/man4/sched_4bsd.4 | 72 | ||||
-rw-r--r-- | share/man/man4/sched_ule.4 | 83 |
3 files changed, 157 insertions, 0 deletions
diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index 3430eca..fec93b6 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -249,6 +249,8 @@ MAN= aac.4 \ sbp.4 \ sbp_targ.4 \ sbsh.4 \ + sched_4bsd.4 \ + sched_ule.4 \ screen.4 \ scsi.4 \ sem.4 \ diff --git a/share/man/man4/sched_4bsd.4 b/share/man/man4/sched_4bsd.4 new file mode 100644 index 0000000..0b5d9d7 --- /dev/null +++ b/share/man/man4/sched_4bsd.4 @@ -0,0 +1,72 @@ +.\" 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_4BSD 4 +.Sh NAME +.Nm sched_4bsd +.Nd 4.4BSD Scheduler +.Sh SYNOPSIS +.Cd "options SCHED_4BSD" +.Sh DESCRIPTION +.Nm +is the default system scheduler, providing both high throughput and solid +interactive response in the presence of load. +.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. +.It kern.sched.quantum +This read-write sysctl reports or sets the length of the quantum (in +micro-seconds) granted to a thread. +.It kern.sched.ipiwakeup.enabled +This read-write sysctl sets whether or not the scheduler will generate an +inter-processor interrupt (IPI) to an idle CPU when a thread is woken up. +Otherwise, idle CPUs will wait until the next clock tick before looking for +new work. +.It kern.sched.preemption +This read-only sysctl reports whether or not the kernel is configured to +support preemption, which reduces the latency to run lower priority threads +on wakeup. +.El +.Pp +Some sysctls will be available only on systems supporting SMP. +.Sh SEE ALSO +.Xr sched_ule 4 , +.Xr sysctl 8 +.Sh HISTORY +The +.Nm +scheduler has been present, in various forms, since the inception of +.Bx . +.Sh BUGS +While a highly robust and time-tested scheduler, +.Nm +lacks specific knowledge of how to schedule advantageously in non-symetric +processor configurations, such as hyper-threading. diff --git a/share/man/man4/sched_ule.4 b/share/man/man4/sched_ule.4 new file mode 100644 index 0000000..237535e --- /dev/null +++ b/share/man/man4/sched_ule.4 @@ -0,0 +1,83 @@ +.\" 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. |