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diff --git a/usr/src/man/man7/FSS.7 b/usr/src/man/man7/FSS.7 deleted file mode 100644 index 8583d0831e..0000000000 --- a/usr/src/man/man7/FSS.7 +++ /dev/null @@ -1,231 +0,0 @@ -.\" Copyright (c) 2001, Sun Microsystems, Inc. All Rights Reserved -.\" Copyright 2019 Joyent, Inc. -.\" -.\" The contents of this file are subject to the terms of the -.\" Common Development and Distribution License (the "License"). -.\" You may not use this file except in compliance with the License. -.\" -.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE -.\" or http://www.opensolaris.org/os/licensing. -.\" See the License for the specific language governing permissions -.\" and limitations under the License. -.\" -.\" When distributing Covered Code, include this CDDL HEADER in each -.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE. -.\" If applicable, add the following below this CDDL HEADER, with the -.\" fields enclosed by brackets "[]" replaced with your own identifying -.\" information: Portions Copyright [yyyy] [name of copyright owner] -.\" -.Dd December 17, 2019 -.Dt FSS 7 -.Os -.Sh NAME -.Nm FSS -.Nd Fair share scheduler -.Sh DESCRIPTION -The fair share scheduler (FSS) guarantees application performance by explicitly -allocating shares of CPU resources to projects. -A share indicates a project's -entitlement to available CPU resources. -Because shares are meaningful only in -comparison with other project's shares, the absolute quantity of shares is not -important. -Any number that is in proportion with the desired CPU entitlement -can be used. -.Pp -The goals of the FSS scheduler differ from the traditional time-sharing -scheduling class (TS). -In addition to scheduling individual LWPs, the FSS -scheduler schedules projects against each other, making it impossible for any -project to acquire more CPU cycles simply by running more processes -concurrently. -.Pp -A project's entitlement is individually calculated by FSS independently for -each processor set if the project contains processes bound to them. -If a -project is running on more than one processor set, it can have different -entitlements on every set. -A project's entitlement is defined as a ratio -between the number of shares given to a project and the sum of shares of all -active projects running on the same processor set. -An active project is one -that has at least one running or runnable process. -Entitlements are recomputed -whenever any project becomes active or inactive, or whenever the number of -shares is changed. -.Pp -Processor sets represent virtual machines in the FSS scheduling class and -processes are scheduled independently in each processor set. -That is, processes -compete with each other only if they are running on the same processor set. -When a processor set is destroyed, all processes that were bound to it are -moved to the default processor set, which always exists. -Empty processor sets -(that is, sets without processors in them) have no impact on the FSS scheduler -behavior. -.Pp -If a processor set contains a mix of TS/IA and FSS processes, the fairness of -the FSS scheduling class can be compromised because these classes use the same -range of priorities. -Fairness is most significantly affected if processes -running in the TS scheduling class are CPU-intensive and are bound to -processors within the processor set. -As a result, you should avoid having -processes from TS/IA and FSS classes share the same processor set. -RT and FSS -processes use disjoint priority ranges and therefore can share processor sets. -.Pp -As projects execute, their CPU usage is accumulated over time. -The FSS -scheduler periodically decays CPU usages of every project by multiplying it -with a decay factor, ensuring that more recent CPU usage has greater weight -when taken into account for scheduling. -The FSS scheduler continually adjusts -priorities of all processes to make each project's relative CPU usage converge -with its entitlement. -.Pp -While FSS is designed to fairly allocate cycles over a long-term time period, -it is possible that projects will not receive their allocated shares worth of -CPU cycles due to uneven demand. -This makes one-shot, instantaneous analysis of -FSS performance data unreliable. -.Pp -Note that share is not the same as utilization. -A project may be allocated 50% -of the system, although on the average, it uses just 20%. -Shares serve to cap a -project's CPU usage only when there is competition from other projects running -on the same processor set. -When there is no competition, utilization may be -larger than entitlement based on shares. -Allocating a small share to a busy -project slows it down but does not prevent it from completing its work if the -system is not saturated. -.Pp -The configuration of CPU shares is managed by the name server as a property of -the -.Xr project 4 -database. -In the following example, an entry in the -.Pa /etc/project -file sets the number of shares for project -.Sy x-files -to 10: -.Bd -literal -offset 2n -x-files:100::::project.cpu-shares=(privileged,10,none) -.Ed -.Pp -Projects with undefined number of shares are given one share each. -This means -that such projects are treated with equal importance. -Projects with 0 shares -only run when there are no projects with non-zero shares competing for the same -processor set. -The maximum number of shares that can be assigned to one project -is 65535. -.Pp -You can use the -.Xr prctl 1 -command to determine the current share -assignment for a given project: -.Bd -literal -offset 2n -$ prctl -n project.cpu-shares -i project x-files -.Ed -.Pp -or to change the amount of shares if you have root privileges: -.Bd -literal -offset 2n -# prctl -r -n project.cpu-shares -v 5 -i project x-files -.Ed -.Pp -See the -.Xr prctl 1 -man page for additional information on how to modify and -examine resource controls associated with active processes, tasks, or projects -on the system. -See -.Xr resource_controls 5 -for a description of the resource -controls supported in the current release of the Solaris operating system. -.Pp -By default, project -.Sy system -(project ID 0) includes all system daemons -started by initialization scripts and has an -.Dq unlimited -amount of shares. -That -is, it is always scheduled first no matter how many shares are given to other -projects. -.Pp -The following command sets FSS as the default scheduler for the system: -.Bd -literal -offset 2n -# dispadmin -d FSS -.Ed -.Pp -This change will take effect on the next reboot. -Alternatively, you can move -processes from the time-share scheduling class (as well as the special case of -init) into the FSS class without changing your default scheduling class and -rebooting by becoming -.Sy root , -and then using the -.Xr priocntl 1 -command, as shown in the following example: -.Bd -literal -offset 2n -# priocntl -s -c FSS -i class TS -# priocntl -s -c FSS -i pid 1 -.Ed -.Sh CONFIGURING SCHEDULER WITH DISPADMIN -You can use the -.Xr dispadmin 1M -command to examine and tune the FSS -scheduler's time quantum value. -Time quantum is the amount of time that a -thread is allowed to run before it must relinquish the processor. -The following -example dumps the current time quantum for the fair share scheduler: -.Bd -literal -offset 2n -$ dispadmin -g -c FSS - # - # Fair Share Scheduler Configuration - # - RES=1000 - # - # Time Quantum - # - QUANTUM=110 -.Ed -.Pp -The value of the QUANTUM represents some fraction of a second with the -fractional value determined by the reciprocal value of RES. -With the default -value of RES = 1000, the reciprocal of 1000 is \&.001, or milliseconds. -Thus, by -default, the QUANTUM value represents the time quantum in milliseconds. -.Pp -If you change the RES value using -.Xr dispadmin 1M -with the -.Fl r -option, you also change the QUANTUM value. -For example, instead of quantum of 110 with RES -of 1000, a quantum of 11 with a RES of 100 results. -The fractional unit is different while the amount of time is the same. -.Pp -You can use the -.Fl s -option to change the time quantum value. -Note that such changes are not preserved across reboot. -Please refer to the -.Xr dispadmin 1M -man page for additional information. -.Sh SEE ALSO -.Xr prctl 1 , -.Xr priocntl 1 , -.Xr dispadmin 1M , -.Xr psrset 1M , -.Xr priocntl 2 , -.Xr project 4 , -.Xr resource_controls 5 -.Pp -.%T System Administration Guide: Virtualization Using the Solaris Operating System |