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diff --git a/schedutils/chrt.1.adoc b/schedutils/chrt.1.adoc new file mode 100644 index 0000000..6ccba7d --- /dev/null +++ b/schedutils/chrt.1.adoc @@ -0,0 +1,153 @@ +//po4a: entry man manual +//// +chrt(1) manpage + +Copyright (C) 2004 Robert Love +Copyright (C) 2015 Karel Zak <kzak@redhat.com> + +This is free documentation; you can redistribute it and/or +modify it under the terms of the GNU General Public License, +version 2, as published by the Free Software Foundation. + +The GNU General Public License's references to "object code" +and "executables" are to be interpreted as the output of any +document formatting or typesetting system, including +intermediate and printed output. + +This manual is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License along +with this program; if not, write to the Free Software Foundation, Inc., +51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. +//// += chrt(1) +:doctype: manpage +:man manual: User Commands +:man source: util-linux {release-version} +:page-layout: base +:command: chrt +:colon: : + +== NAME + +chrt - manipulate the real-time attributes of a process + +== SYNOPSIS + +*chrt* [options] _priority command argument_ ... + +*chrt* [options] *-p* [_priority_] _PID_ + +== DESCRIPTION + +*chrt* sets or retrieves the real-time scheduling attributes of an existing _PID_, or runs _command_ with the given attributes. + +== POLICIES + +*-o*, *--other*:: +Set scheduling policy to *SCHED_OTHER* (time-sharing scheduling). This is the default Linux scheduling policy. + +*-f*, *--fifo*:: +Set scheduling policy to *SCHED_FIFO* (first in-first out). + +*-r*, *--rr*:: +Set scheduling policy to *SCHED_RR* (round-robin scheduling). When no policy is defined, the *SCHED_RR* is used as the default. + +*-b*, *--batch*:: +Set scheduling policy to *SCHED_BATCH* (scheduling batch processes). Linux-specific, supported since 2.6.16. The priority argument has to be set to zero. + +*-i*, *--idle*:: +Set scheduling policy to *SCHED_IDLE* (scheduling very low priority jobs). Linux-specific, supported since 2.6.23. The priority argument has to be set to zero. + +*-d*, *--deadline*:: +Set scheduling policy to *SCHED_DEADLINE* (sporadic task model deadline scheduling). Linux-specific, supported since 3.14. The priority argument has to be set to zero. See also *--sched-runtime*, *--sched-deadline* and *--sched-period*. The relation between the options required by the kernel is runtime <= deadline <= period. *chrt* copies _period_ to _deadline_ if *--sched-deadline* is not specified and _deadline_ to _runtime_ if *--sched-runtime* is not specified. It means that at least *--sched-period* has to be specified. See *sched*(7) for more details. + +== SCHEDULING OPTIONS + +*-T*, *--sched-runtime* _nanoseconds_:: +Specifies runtime parameter for *SCHED_DEADLINE* policy (Linux-specific). + +*-P*, *--sched-period* _nanoseconds_:: +Specifies period parameter for *SCHED_DEADLINE* policy (Linux-specific). + +*-D*, *--sched-deadline* _nanoseconds_:: +Specifies deadline parameter for *SCHED_DEADLINE* policy (Linux-specific). + +*-R*, *--reset-on-fork*:: +Use *SCHED_RESET_ON_FORK* or *SCHED_FLAG_RESET_ON_FORK* flag. Linux-specific, supported since 2.6.31. + +Each thread has a _reset-on-fork_ scheduling flag. When this flag is set, children created by *fork*(2) do not inherit privileged scheduling policies. After the _reset-on-fork_ flag has been enabled, it can be reset only if the thread has the *CAP_SYS_NICE* capability. This flag is disabled in child processes created by *fork*(2). + +More precisely, if the _reset-on-fork_ flag is set, the following rules apply for subsequently created children: + +* If the calling thread has a scheduling policy of *SCHED_FIFO* or *SCHED_RR*, the policy is reset to *SCHED_OTHER* in child processes. + +* If the calling process has a negative nice value, the nice value is reset to zero in child processes. + +== OPTIONS + +*-a*, *--all-tasks*:: +Set or retrieve the scheduling attributes of all the tasks (threads) for a given PID. + +*-m*, *--max*:: +Show minimum and maximum valid priorities, then exit. + +*-p*, *--pid*:: +Operate on an existing PID and do not launch a new task. + +*-v*, *--verbose*:: +Show status information. + +include::man-common/help-version.adoc[] + +== USAGE + +//TRANSLATORS: Keep {colon} untranslated +The default behavior is to run a new command{colon}:: + +*chrt* _priority_ _command_ [_arguments_] + +//TRANSLATORS: Keep {colon} untranslated +You can also retrieve the real-time attributes of an existing task{colon}:: + +*chrt -p* _PID_ + +//TRANSLATORS: Keep {colon} untranslated +Or set them{colon}:: + +*chrt -r -p* _priority PID_ + +== PERMISSIONS + +A user must possess *CAP_SYS_NICE* to change the scheduling attributes of a process. Any user can retrieve the scheduling information. + +== NOTES + +Only *SCHED_FIFO*, *SCHED_OTHER* and *SCHED_RR* are part of POSIX 1003.1b Process Scheduling. The other scheduling attributes may be ignored on some systems. + +Linux' default scheduling policy is *SCHED_OTHER*. + +== AUTHORS + +mailto:rml@tech9.net[Robert Love], +mailto:kzak@redhat.com[Karel Zak] + +== SEE ALSO + +*nice*(1), +*renice*(1), +*taskset*(1), +*sched*(7) + +See *sched_setscheduler*(2) for a description of the Linux scheduling scheme. + +include::man-common/bugreports.adoc[] + +include::man-common/footer.adoc[] + +ifdef::translation[] +include::man-common/translation.adoc[] +endif::[] |