xref: /freebsd/share/man/man4/sched_ule.4 (revision 9b99e9b91063ac83afb5baea9c260a0430cf7442)
19b99e9b9SRobert Watson.\" Copyright (c) 2005 Robert N. M. Watson
29b99e9b9SRobert Watson.\" All rights reserved.
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79b99e9b9SRobert Watson.\" 1. Redistributions of source code must retain the above copyright
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259b99e9b9SRobert Watson.\" $FreeBSD$
269b99e9b9SRobert Watson.\"
279b99e9b9SRobert Watson.Dd April 7, 2005
289b99e9b9SRobert Watson.Os
299b99e9b9SRobert Watson.Dt SCHED_ULE 4
309b99e9b9SRobert Watson.Sh NAME
319b99e9b9SRobert Watson.Nm sched_ule
329b99e9b9SRobert Watson.Nd ULE Scheduler
339b99e9b9SRobert Watson.Sh SYNOPSIS
349b99e9b9SRobert Watson.Cd "options SCHED_ULE"
359b99e9b9SRobert Watson.Sh DESCRIPTION
369b99e9b9SRobert Watson.Nm
379b99e9b9SRobert Watsonis an experimental scheduler that provides a number of advanced scheduler
389b99e9b9SRobert Watsonfeatures not present in
399b99e9b9SRobert Watson.Xr sched_4bsd 4 ,
409b99e9b9SRobert Watsonthe default system scheduler.
419b99e9b9SRobert WatsonThese features address SMP and interactivity and include:
429b99e9b9SRobert Watson.Pp
439b99e9b9SRobert Watson.Bl -bullet -compact -offset indent
449b99e9b9SRobert Watson.It
459b99e9b9SRobert WatsonThread CPU affinity.
469b99e9b9SRobert Watson.It
479b99e9b9SRobert WatsonCPU topology awareness, including for hyper-threading.
489b99e9b9SRobert Watson.It
499b99e9b9SRobert WatsonPer-CPU run queues.
509b99e9b9SRobert Watson.It
519b99e9b9SRobert WatsonInteractivity heuristics that detect interactive applications and schedules
529b99e9b9SRobert Watsonthem preferentially under high load.
539b99e9b9SRobert Watson.El
549b99e9b9SRobert Watson.Pp
559b99e9b9SRobert WatsonThe following sysctls are relevant to the operation of
569b99e9b9SRobert Watson.Nm :
579b99e9b9SRobert Watson.Bl -tag -width indent
589b99e9b9SRobert Watson.It kern.sched.name
599b99e9b9SRobert WatsonThis read-only sysctl reports the name of the active scheduler.
609b99e9b9SRobert Watson.El
619b99e9b9SRobert Watson.Pp
629b99e9b9SRobert Watson.Nm
639b99e9b9SRobert Watsonis disabled by default as it is experimental.
649b99e9b9SRobert WatsonSee the bugs section for more information.
659b99e9b9SRobert Watson.Sh SEE ALSO
669b99e9b9SRobert Watson.Xr sched_4bsd 4 ,
679b99e9b9SRobert Watson.Xr sysctl 8
689b99e9b9SRobert Watson.Sh HISTORY
699b99e9b9SRobert WatsonThe
709b99e9b9SRobert Watson.Nm
719b99e9b9SRobert Watsonscheduler first appeared in
729b99e9b9SRobert Watson.Fx 5.1 .
739b99e9b9SRobert Watson.Sh AUTHORS
749b99e9b9SRobert Watson.An Jeff Roberson
759b99e9b9SRobert Watson.Aq jeff@FreeBSD.org
769b99e9b9SRobert Watson.Sh BUGS
779b99e9b9SRobert WatsonAs an experimental scheduler,
789b99e9b9SRobert Watson.Nm
799b99e9b9SRobert Watsonis not enabled by default due to a number of known issues, including weak
809b99e9b9SRobert Watsonperformance with several known workloads, and reports of instability.
819b99e9b9SRobert WatsonDeployment of
829b99e9b9SRobert Watson.Nm
839b99e9b9SRobert Watsonin production environments should be done cautiously.
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