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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 19:10:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 19:10:49 +0000 |
commit | cfe5e3905201349e9cf3f95d52ff4bd100bde37d (patch) | |
tree | d0baf160cbee3195249d095f85e52d20c21acf02 /schedutils/chrt.1 | |
parent | Initial commit. (diff) | |
download | util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.tar.xz util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.zip |
Adding upstream version 2.39.3.upstream/2.39.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'schedutils/chrt.1')
-rw-r--r-- | schedutils/chrt.1 | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/schedutils/chrt.1 b/schedutils/chrt.1 new file mode 100644 index 0000000..b99b532 --- /dev/null +++ b/schedutils/chrt.1 @@ -0,0 +1,234 @@ +'\" t +.\" Title: chrt +.\" Author: [see the "AUTHOR(S)" section] +.\" Generator: Asciidoctor 2.0.20 +.\" Date: 2023-11-21 +.\" Manual: User Commands +.\" Source: util-linux 2.39.3 +.\" Language: English +.\" +.TH "CHRT" "1" "2023-11-21" "util\-linux 2.39.3" "User Commands" +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.ss \n[.ss] 0 +.nh +.ad l +.de URL +\fI\\$2\fP <\\$1>\\$3 +.. +.als MTO URL +.if \n[.g] \{\ +. mso www.tmac +. am URL +. ad l +. . +. am MTO +. ad l +. . +. LINKSTYLE blue R < > +.\} +.SH "NAME" +chrt \- manipulate the real\-time attributes of a process +.SH "SYNOPSIS" +.sp +\fBchrt\fP [options] \fIpriority command argument\fP ... +.sp +\fBchrt\fP [options] \fB\-p\fP [\fIpriority\fP] \fIPID\fP +.SH "DESCRIPTION" +.sp +\fBchrt\fP sets or retrieves the real\-time scheduling attributes of an existing \fIPID\fP, or runs \fIcommand\fP with the given attributes. +.SH "POLICIES" +.sp +\fB\-o\fP, \fB\-\-other\fP +.RS 4 +Set scheduling policy to \fBSCHED_OTHER\fP (time\-sharing scheduling). This is the default Linux scheduling policy. +.RE +.sp +\fB\-f\fP, \fB\-\-fifo\fP +.RS 4 +Set scheduling policy to \fBSCHED_FIFO\fP (first in\-first out). +.RE +.sp +\fB\-r\fP, \fB\-\-rr\fP +.RS 4 +Set scheduling policy to \fBSCHED_RR\fP (round\-robin scheduling). When no policy is defined, the \fBSCHED_RR\fP is used as the default. +.RE +.sp +\fB\-b\fP, \fB\-\-batch\fP +.RS 4 +Set scheduling policy to \fBSCHED_BATCH\fP (scheduling batch processes). Linux\-specific, supported since 2.6.16. The priority argument has to be set to zero. +.RE +.sp +\fB\-i\fP, \fB\-\-idle\fP +.RS 4 +Set scheduling policy to \fBSCHED_IDLE\fP (scheduling very low priority jobs). Linux\-specific, supported since 2.6.23. The priority argument has to be set to zero. +.RE +.sp +\fB\-d\fP, \fB\-\-deadline\fP +.RS 4 +Set scheduling policy to \fBSCHED_DEADLINE\fP (sporadic task model deadline scheduling). Linux\-specific, supported since 3.14. The priority argument has to be set to zero. See also \fB\-\-sched\-runtime\fP, \fB\-\-sched\-deadline\fP and \fB\-\-sched\-period\fP. The relation between the options required by the kernel is runtime \(lA deadline \(lA period. \fBchrt\fP copies \fIperiod\fP to \fIdeadline\fP if \fB\-\-sched\-deadline\fP is not specified and \fIdeadline\fP to \fIruntime\fP if \fB\-\-sched\-runtime\fP is not specified. It means that at least \fB\-\-sched\-period\fP has to be specified. See \fBsched\fP(7) for more details. +.RE +.SH "SCHEDULING OPTIONS" +.sp +\fB\-T\fP, \fB\-\-sched\-runtime\fP \fInanoseconds\fP +.RS 4 +Specifies runtime parameter for \fBSCHED_DEADLINE\fP policy (Linux\-specific). +.RE +.sp +\fB\-P\fP, \fB\-\-sched\-period\fP \fInanoseconds\fP +.RS 4 +Specifies period parameter for \fBSCHED_DEADLINE\fP policy (Linux\-specific). Note that the kernel\(cqs lower limit is 100 milliseconds. +.RE +.sp +\fB\-D\fP, \fB\-\-sched\-deadline\fP \fInanoseconds\fP +.RS 4 +Specifies deadline parameter for \fBSCHED_DEADLINE\fP policy (Linux\-specific). +.RE +.sp +\fB\-R\fP, \fB\-\-reset\-on\-fork\fP +.RS 4 +Use \fBSCHED_RESET_ON_FORK\fP or \fBSCHED_FLAG_RESET_ON_FORK\fP flag. Linux\-specific, supported since 2.6.31. +.sp +Each thread has a \fIreset\-on\-fork\fP scheduling flag. When this flag is set, children created by \fBfork\fP(2) do not inherit privileged scheduling policies. After the \fIreset\-on\-fork\fP flag has been enabled, it can be reset only if the thread has the \fBCAP_SYS_NICE\fP capability. This flag is disabled in child processes created by \fBfork\fP(2). +.sp +More precisely, if the \fIreset\-on\-fork\fP flag is set, the following rules apply for subsequently created children: +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +. sp -1 +. IP \(bu 2.3 +.\} +If the calling thread has a scheduling policy of \fBSCHED_FIFO\fP or \fBSCHED_RR\fP, the policy is reset to \fBSCHED_OTHER\fP in child processes. +.RE +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +. sp -1 +. IP \(bu 2.3 +.\} +If the calling process has a negative nice value, the nice value is reset to zero in child processes. +.RE +.RE +.SH "OPTIONS" +.sp +\fB\-a\fP, \fB\-\-all\-tasks\fP +.RS 4 +Set or retrieve the scheduling attributes of all the tasks (threads) for a given PID. +.RE +.sp +\fB\-m\fP, \fB\-\-max\fP +.RS 4 +Show minimum and maximum valid priorities, then exit. +.RE +.sp +\fB\-p\fP, \fB\-\-pid\fP +.RS 4 +Operate on an existing PID and do not launch a new task. +.RE +.sp +\fB\-v\fP, \fB\-\-verbose\fP +.RS 4 +Show status information. +.RE +.sp +\fB\-h\fP, \fB\-\-help\fP +.RS 4 +Display help text and exit. +.RE +.sp +\fB\-V\fP, \fB\-\-version\fP +.RS 4 +Print version and exit. +.RE +.SH "EXAMPLES" +.sp +The default behavior is to run a new command: +.RS 4 +.RE +.RS 3 +.ll -.6i +.sp +\fBchrt\fP \fIpriority\fP \fIcommand\fP [\fIarguments\fP] +.br +.RE +.ll +.sp +You can also retrieve the real\-time attributes of an existing task: +.RS 4 +.RE +.RS 3 +.ll -.6i +.sp +\fBchrt \-p\fP \fIPID\fP +.br +.RE +.ll +.sp +Or set them: +.RS 4 +.RE +.RS 3 +.ll -.6i +.sp +\fBchrt \-r \-p\fP \fIpriority PID\fP +.br +.RE +.ll +.sp +This, for example, sets real\-time scheduling to priority \fI30\fP for the process \fIPID\fP with the \fBSCHED_RR\fP (round\-robin) class: +.RS 4 +.RE +.RS 3 +.ll -.6i +.sp +\fBchrt \-r \-p 30\fP \fIPID\fP +.br +.RE +.ll +.sp +Reset priorities to default for a process: +.RS 4 +.RE +.RS 3 +.ll -.6i +.sp +\fBchrt \-o \-p 0\fP \fIPID\fP +.br +.RE +.ll +.sp +See \fBsched\fP(7) for a detailed discussion of the different scheduler classes and how they interact. +.SH "PERMISSIONS" +.sp +A user must possess \fBCAP_SYS_NICE\fP to change the scheduling attributes of a process. Any user can retrieve the scheduling information. +.SH "NOTES" +.sp +Only \fBSCHED_FIFO\fP, \fBSCHED_OTHER\fP and \fBSCHED_RR\fP are part of POSIX 1003.1b Process Scheduling. The other scheduling attributes may be ignored on some systems. +.sp +Linux\*(Aq default scheduling policy is \fBSCHED_OTHER\fP. +.SH "AUTHORS" +.sp +.MTO "rml\(attech9.net" "Robert Love" "," +.MTO "kzak\(atredhat.com" "Karel Zak" "" +.SH "SEE ALSO" +.sp +\fBnice\fP(1), +\fBrenice\fP(1), +\fBtaskset\fP(1), +\fBsched\fP(7) +.sp +See \fBsched_setscheduler\fP(2) for a description of the Linux scheduling scheme. +.SH "REPORTING BUGS" +.sp +For bug reports, use the issue tracker at \c +.URL "https://github.com/util\-linux/util\-linux/issues" "" "." +.SH "AVAILABILITY" +.sp +The \fBchrt\fP command is part of the util\-linux package which can be downloaded from \c +.URL "https://www.kernel.org/pub/linux/utils/util\-linux/" "Linux Kernel Archive" "."
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