path: root/templates/man7/sched.7.pot

# SOME DESCRIPTIVE TITLE
# Copyright (C) YEAR Free Software Foundation, Inc.
# This file is distributed under the same license as the PACKAGE package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"POT-Creation-Date: 2024-03-01 17:07+0100\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"Language: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

#. type: TH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "sched"
msgstr ""

#. type: TH
#: archlinux fedora-40 fedora-rawhide mageia-cauldron
#, no-wrap
msgid "2023-10-31"
msgstr ""

#. type: TH
#: archlinux fedora-40 fedora-rawhide mageia-cauldron
#, no-wrap
msgid "Linux man-pages 6.06"
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "NAME"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "sched - overview of CPU scheduling"
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "DESCRIPTION"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 2.6.23, the default scheduler is CFS, the \"Completely Fair "
"Scheduler\".  The CFS scheduler replaced the earlier \"O(1)\" scheduler."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "API summary"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Linux provides the following system calls for controlling the CPU scheduling "
"behavior, policy, and priority of processes (or, more precisely, threads)."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<nice>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Set a new nice value for the calling thread, and return the new nice value."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<getpriority>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Return the nice value of a thread, a process group, or the set of threads "
"owned by a specified user."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<setpriority>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Set the nice value of a thread, a process group, or the set of threads owned "
"by a specified user."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_setscheduler>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Set the scheduling policy and parameters of a specified thread."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_getscheduler>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Return the scheduling policy of a specified thread."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_setparam>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Set the scheduling parameters of a specified thread."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_getparam>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Fetch the scheduling parameters of a specified thread."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_get_priority_max>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Return the maximum priority available in a specified scheduling policy."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_get_priority_min>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "Return the minimum priority available in a specified scheduling policy."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_rr_get_interval>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Fetch the quantum used for threads that are scheduled under the \"round-"
"robin\" scheduling policy."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_yield>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Cause the caller to relinquish the CPU, so that some other thread be "
"executed."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_setaffinity>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "(Linux-specific)  Set the CPU affinity of a specified thread."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_getaffinity>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "(Linux-specific)  Get the CPU affinity of a specified thread."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_setattr>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Set the scheduling policy and parameters of a specified thread.  This (Linux-"
"specific) system call provides a superset of the functionality of "
"B<sched_setscheduler>(2)  and B<sched_setparam>(2)."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "B<sched_getattr>(2)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Fetch the scheduling policy and parameters of a specified thread.  This "
"(Linux-specific) system call provides a superset of the functionality of "
"B<sched_getscheduler>(2)  and B<sched_getparam>(2)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Scheduling policies"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The scheduler is the kernel component that decides which runnable thread "
"will be executed by the CPU next.  Each thread has an associated scheduling "
"policy and a I<static> scheduling priority, I<sched_priority>.  The "
"scheduler makes its decisions based on knowledge of the scheduling policy "
"and static priority of all threads on the system."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"For threads scheduled under one of the normal scheduling policies "
"(B<SCHED_OTHER>, B<SCHED_IDLE>, B<SCHED_BATCH>), I<sched_priority> is not "
"used in scheduling decisions (it must be specified as 0)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Processes scheduled under one of the real-time policies (B<SCHED_FIFO>, "
"B<SCHED_RR>) have a I<sched_priority> value in the range 1 (low) to 99 "
"(high).  (As the numbers imply, real-time threads always have higher "
"priority than normal threads.)  Note well: POSIX.1 requires an "
"implementation to support only a minimum 32 distinct priority levels for the "
"real-time policies, and some systems supply just this minimum.  Portable "
"programs should use B<sched_get_priority_min>(2)  and "
"B<sched_get_priority_max>(2)  to find the range of priorities supported for "
"a particular policy."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Conceptually, the scheduler maintains a list of runnable threads for each "
"possible I<sched_priority> value.  In order to determine which thread runs "
"next, the scheduler looks for the nonempty list with the highest static "
"priority and selects the thread at the head of this list."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A thread's scheduling policy determines where it will be inserted into the "
"list of threads with equal static priority and how it will move inside this "
"list."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"All scheduling is preemptive: if a thread with a higher static priority "
"becomes ready to run, the currently running thread will be preempted and "
"returned to the wait list for its static priority level.  The scheduling "
"policy determines the ordering only within the list of runnable threads with "
"equal static priority."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SCHED_FIFO: First in-first out scheduling"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<SCHED_FIFO> can be used only with static priorities higher than 0, which "
"means that when a B<SCHED_FIFO> thread becomes runnable, it will always "
"immediately preempt any currently running B<SCHED_OTHER>, B<SCHED_BATCH>, or "
"B<SCHED_IDLE> thread.  B<SCHED_FIFO> is a simple scheduling algorithm "
"without time slicing.  For threads scheduled under the B<SCHED_FIFO> policy, "
"the following rules apply:"
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "\\[bu]"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A running B<SCHED_FIFO> thread that has been preempted by another thread of "
"higher priority will stay at the head of the list for its priority and will "
"resume execution as soon as all threads of higher priority are blocked again."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"When a blocked B<SCHED_FIFO> thread becomes runnable, it will be inserted at "
"the end of the list for its priority."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If a call to B<sched_setscheduler>(2), B<sched_setparam>(2), "
"B<sched_setattr>(2), B<pthread_setschedparam>(3), or "
"B<pthread_setschedprio>(3)  changes the priority of the running or runnable "
"B<SCHED_FIFO> thread identified by I<pid> the effect on the thread's "
"position in the list depends on the direction of the change to threads "
"priority:"
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "(a)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the thread's priority is raised, it is placed at the end of the list for "
"its new priority.  As a consequence, it may preempt a currently running "
"thread with the same priority."
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "(b)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the thread's priority is unchanged, its position in the run list is "
"unchanged."
msgstr ""

#. type: IP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "(c)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the thread's priority is lowered, it is placed at the front of the list "
"for its new priority."
msgstr ""

#.  In Linux 2.2.x and Linux 2.4.x, the thread is placed at the front of the queue
#.  In Linux 2.0.x, the Right Thing happened: the thread went to the back -- MTK
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"According to POSIX.1-2008, changes to a thread's priority (or policy) using "
"any mechanism other than B<pthread_setschedprio>(3)  should result in the "
"thread being placed at the end of the list for its priority."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "A thread calling B<sched_yield>(2)  will be put at the end of the list."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"No other events will move a thread scheduled under the B<SCHED_FIFO> policy "
"in the wait list of runnable threads with equal static priority."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A B<SCHED_FIFO> thread runs until either it is blocked by an I/O request, it "
"is preempted by a higher priority thread, or it calls B<sched_yield>(2)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SCHED_RR: Round-robin scheduling"
msgstr ""

#.  On Linux 2.4, the length of the RR interval is influenced
#.  by the process nice value -- MTK
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<SCHED_RR> is a simple enhancement of B<SCHED_FIFO>.  Everything described "
"above for B<SCHED_FIFO> also applies to B<SCHED_RR>, except that each thread "
"is allowed to run only for a maximum time quantum.  If a B<SCHED_RR> thread "
"has been running for a time period equal to or longer than the time quantum, "
"it will be put at the end of the list for its priority.  A B<SCHED_RR> "
"thread that has been preempted by a higher priority thread and subsequently "
"resumes execution as a running thread will complete the unexpired portion of "
"its round-robin time quantum.  The length of the time quantum can be "
"retrieved using B<sched_rr_get_interval>(2)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SCHED_DEADLINE: Sporadic task model deadline scheduling"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 3.14, Linux provides a deadline scheduling policy "
"(B<SCHED_DEADLINE>).  This policy is currently implemented using GEDF "
"(Global Earliest Deadline First)  in conjunction with CBS (Constant "
"Bandwidth Server).  To set and fetch this policy and associated attributes, "
"one must use the Linux-specific B<sched_setattr>(2)  and "
"B<sched_getattr>(2)  system calls."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A sporadic task is one that has a sequence of jobs, where each job is "
"activated at most once per period.  Each job also has a I<relative "
"deadline>, before which it should finish execution, and a I<computation "
"time>, which is the CPU time necessary for executing the job.  The moment "
"when a task wakes up because a new job has to be executed is called the "
"I<arrival time> (also referred to as the request time or release time).  The "
"I<start time> is the time at which a task starts its execution.  The "
"I<absolute deadline> is thus obtained by adding the relative deadline to the "
"arrival time."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The following diagram clarifies these terms:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"arrival/wakeup                    absolute deadline\n"
"     |    start time                    |\n"
"     |        |                         |\n"
"     v        v                         v\n"
"-----x--------xooooooooooooooooo--------x--------x---\n"
"              |E<lt>- comp. time -E<gt>|\n"
"     |E<lt>------- relative deadline ------E<gt>|\n"
"     |E<lt>-------------- period -------------------E<gt>|\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"When setting a B<SCHED_DEADLINE> policy for a thread using "
"B<sched_setattr>(2), one can specify three parameters: I<Runtime>, "
"I<Deadline>, and I<Period>.  These parameters do not necessarily correspond "
"to the aforementioned terms: usual practice is to set Runtime to something "
"bigger than the average computation time (or worst-case execution time for "
"hard real-time tasks), Deadline to the relative deadline, and Period to the "
"period of the task.  Thus, for B<SCHED_DEADLINE> scheduling, we have:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"arrival/wakeup                    absolute deadline\n"
"     |    start time                    |\n"
"     |        |                         |\n"
"     v        v                         v\n"
"-----x--------xooooooooooooooooo--------x--------x---\n"
"              |E<lt>-- Runtime -------E<gt>|\n"
"     |E<lt>----------- Deadline -----------E<gt>|\n"
"     |E<lt>-------------- Period -------------------E<gt>|\n"
msgstr ""

#.  FIXME It looks as though specifying sched_period as 0 means
#.  "make sched_period the same as sched_deadline".
#.  This needs to be documented.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The three deadline-scheduling parameters correspond to the I<sched_runtime>, "
"I<sched_deadline>, and I<sched_period> fields of the I<sched_attr> "
"structure; see B<sched_setattr>(2).  These fields express values in "
"nanoseconds.  If I<sched_period> is specified as 0, then it is made the same "
"as I<sched_deadline>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid "The kernel requires that:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "sched_runtime E<lt>= sched_deadline E<lt>= sched_period\n"
msgstr ""

#.  See __checkparam_dl in kernel/sched/core.c
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In addition, under the current implementation, all of the parameter values "
"must be at least 1024 (i.e., just over one microsecond, which is the "
"resolution of the implementation), and less than 2\\[ha]63.  If any of these "
"checks fails, B<sched_setattr>(2)  fails with the error B<EINVAL>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The CBS guarantees non-interference between tasks, by throttling threads "
"that attempt to over-run their specified Runtime."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"To ensure deadline scheduling guarantees, the kernel must prevent situations "
"where the set of B<SCHED_DEADLINE> threads is not feasible (schedulable) "
"within the given constraints.  The kernel thus performs an admittance test "
"when setting or changing B<SCHED_DEADLINE> policy and attributes.  This "
"admission test calculates whether the change is feasible; if it is not, "
"B<sched_setattr>(2)  fails with the error B<EBUSY>."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"For example, it is required (but not necessarily sufficient) for the total "
"utilization to be less than or equal to the total number of CPUs available, "
"where, since each thread can maximally run for Runtime per Period, that "
"thread's utilization is its Runtime divided by its Period."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In order to fulfill the guarantees that are made when a thread is admitted "
"to the B<SCHED_DEADLINE> policy, B<SCHED_DEADLINE> threads are the highest "
"priority (user controllable) threads in the system; if any B<SCHED_DEADLINE> "
"thread is runnable, it will preempt any thread scheduled under one of the "
"other policies."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A call to B<fork>(2)  by a thread scheduled under the B<SCHED_DEADLINE> "
"policy fails with the error B<EAGAIN>, unless the thread has its reset-on-"
"fork flag set (see below)."
msgstr ""

#
#.  FIXME Calling sched_getparam() on a SCHED_DEADLINE thread
#.  fails with EINVAL, but sched_getscheduler() succeeds.
#.  Is that intended? (Why?)
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A B<SCHED_DEADLINE> thread that calls B<sched_yield>(2)  will yield the "
"current job and wait for a new period to begin."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SCHED_OTHER: Default Linux time-sharing scheduling"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<SCHED_OTHER> can be used at only static priority 0 (i.e., threads under "
"real-time policies always have priority over B<SCHED_OTHER> processes).  "
"B<SCHED_OTHER> is the standard Linux time-sharing scheduler that is intended "
"for all threads that do not require the special real-time mechanisms."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The thread to run is chosen from the static priority 0 list based on a "
"I<dynamic> priority that is determined only inside this list.  The dynamic "
"priority is based on the nice value (see below)  and is increased for each "
"time quantum the thread is ready to run, but denied to run by the "
"scheduler.  This ensures fair progress among all B<SCHED_OTHER> threads."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"In the Linux kernel source code, the B<SCHED_OTHER> policy is actually named "
"B<SCHED_NORMAL>."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "The nice value"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The nice value is an attribute that can be used to influence the CPU "
"scheduler to favor or disfavor a process in scheduling decisions.  It "
"affects the scheduling of B<SCHED_OTHER> and B<SCHED_BATCH> (see below) "
"processes.  The nice value can be modified using B<nice>(2), "
"B<setpriority>(2), or B<sched_setattr>(2)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"According to POSIX.1, the nice value is a per-process attribute; that is, "
"the threads in a process should share a nice value.  However, on Linux, the "
"nice value is a per-thread attribute: different threads in the same process "
"may have different nice values."
msgstr ""

#.  Linux before 1.3.36 had \-infinity..15.
#.  Since Linux 1.3.43, Linux has the range \-20..19.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The range of the nice value varies across UNIX systems.  On modern Linux, "
"the range is -20 (high priority) to +19 (low priority).  On some other "
"systems, the range is -20..20.  Very early Linux kernels (before Linux 2.0) "
"had the range -infinity..15."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The degree to which the nice value affects the relative scheduling of "
"B<SCHED_OTHER> processes likewise varies across UNIX systems and across "
"Linux kernel versions."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"With the advent of the CFS scheduler in Linux 2.6.23, Linux adopted an "
"algorithm that causes relative differences in nice values to have a much "
"stronger effect.  In the current implementation, each unit of difference in "
"the nice values of two processes results in a factor of 1.25 in the degree "
"to which the scheduler favors the higher priority process.  This causes very "
"low nice values (+19) to truly provide little CPU to a process whenever "
"there is any other higher priority load on the system, and makes high nice "
"values (-20) deliver most of the CPU to applications that require it (e.g., "
"some audio applications)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"On Linux, the B<RLIMIT_NICE> resource limit can be used to define a limit to "
"which an unprivileged process's nice value can be raised; see "
"B<setrlimit>(2)  for details."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"For further details on the nice value, see the subsections on the autogroup "
"feature and group scheduling, below."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SCHED_BATCH: Scheduling batch processes"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(Since Linux 2.6.16.)  B<SCHED_BATCH> can be used only at static priority "
"0.  This policy is similar to B<SCHED_OTHER> in that it schedules the thread "
"according to its dynamic priority (based on the nice value).  The difference "
"is that this policy will cause the scheduler to always assume that the "
"thread is CPU-intensive.  Consequently, the scheduler will apply a small "
"scheduling penalty with respect to wakeup behavior, so that this thread is "
"mildly disfavored in scheduling decisions."
msgstr ""

#.  The following paragraph is drawn largely from the text that
#.  accompanied Ingo Molnar's patch for the implementation of
#.  SCHED_BATCH.
#.  commit b0a9499c3dd50d333e2aedb7e894873c58da3785
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This policy is useful for workloads that are noninteractive, but do not want "
"to lower their nice value, and for workloads that want a deterministic "
"scheduling policy without interactivity causing extra preemptions (between "
"the workload's tasks)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SCHED_IDLE: Scheduling very low priority jobs"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"(Since Linux 2.6.23.)  B<SCHED_IDLE> can be used only at static priority 0; "
"the process nice value has no influence for this policy."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This policy is intended for running jobs at extremely low priority (lower "
"even than a +19 nice value with the B<SCHED_OTHER> or B<SCHED_BATCH> "
"policies)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Resetting scheduling policy for child processes"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Each thread has a reset-on-fork scheduling flag.  When this flag is set, "
"children created by B<fork>(2)  do not inherit privileged scheduling "
"policies.  The reset-on-fork flag can be set by either:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"ORing the B<SCHED_RESET_ON_FORK> flag into the I<policy> argument when "
"calling B<sched_setscheduler>(2)  (since Linux 2.6.32); or"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"specifying the B<SCHED_FLAG_RESET_ON_FORK> flag in I<attr.sched_flags> when "
"calling B<sched_setattr>(2)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Note that the constants used with these two APIs have different names.  The "
"state of the reset-on-fork flag can analogously be retrieved using "
"B<sched_getscheduler>(2)  and B<sched_getattr>(2)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The reset-on-fork feature is intended for media-playback applications, and "
"can be used to prevent applications evading the B<RLIMIT_RTTIME> resource "
"limit (see B<getrlimit>(2))  by creating multiple child processes."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"More precisely, if the reset-on-fork flag is set, the following rules apply "
"for subsequently created children:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the calling thread has a scheduling policy of B<SCHED_FIFO> or "
"B<SCHED_RR>, the policy is reset to B<SCHED_OTHER> in child processes."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the calling process has a negative nice value, the nice value is reset to "
"zero in child processes."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"After the reset-on-fork flag has been enabled, it can be reset only if the "
"thread has the B<CAP_SYS_NICE> capability.  This flag is disabled in child "
"processes created by B<fork>(2)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Privileges and resource limits"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Before Linux 2.6.12, only privileged (B<CAP_SYS_NICE>)  threads can set a "
"nonzero static priority (i.e., set a real-time scheduling policy).  The only "
"change that an unprivileged thread can make is to set the B<SCHED_OTHER> "
"policy, and this can be done only if the effective user ID of the caller "
"matches the real or effective user ID of the target thread (i.e., the thread "
"specified by I<pid>)  whose policy is being changed."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A thread must be privileged (B<CAP_SYS_NICE>)  in order to set or modify a "
"B<SCHED_DEADLINE> policy."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 2.6.12, the B<RLIMIT_RTPRIO> resource limit defines a ceiling on "
"an unprivileged thread's static priority for the B<SCHED_RR> and "
"B<SCHED_FIFO> policies.  The rules for changing scheduling policy and "
"priority are as follows:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If an unprivileged thread has a nonzero B<RLIMIT_RTPRIO> soft limit, then it "
"can change its scheduling policy and priority, subject to the restriction "
"that the priority cannot be set to a value higher than the maximum of its "
"current priority and its B<RLIMIT_RTPRIO> soft limit."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If the B<RLIMIT_RTPRIO> soft limit is 0, then the only permitted changes are "
"to lower the priority, or to switch to a non-real-time policy."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Subject to the same rules, another unprivileged thread can also make these "
"changes, as long as the effective user ID of the thread making the change "
"matches the real or effective user ID of the target thread."
msgstr ""

#.  commit c02aa73b1d18e43cfd79c2f193b225e84ca497c8
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Special rules apply for the B<SCHED_IDLE> policy.  Before Linux 2.6.39, an "
"unprivileged thread operating under this policy cannot change its policy, "
"regardless of the value of its B<RLIMIT_RTPRIO> resource limit.  Since Linux "
"2.6.39, an unprivileged thread can switch to either the B<SCHED_BATCH> or "
"the B<SCHED_OTHER> policy so long as its nice value falls within the range "
"permitted by its B<RLIMIT_NICE> resource limit (see B<getrlimit>(2))."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Privileged (B<CAP_SYS_NICE>)  threads ignore the B<RLIMIT_RTPRIO> limit; as "
"with older kernels, they can make arbitrary changes to scheduling policy and "
"priority.  See B<getrlimit>(2)  for further information on B<RLIMIT_RTPRIO>."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Limiting the CPU usage of real-time and deadline processes"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A nonblocking infinite loop in a thread scheduled under the B<SCHED_FIFO>, "
"B<SCHED_RR>, or B<SCHED_DEADLINE> policy can potentially block all other "
"threads from accessing the CPU forever.  Before Linux 2.6.25, the only way "
"of preventing a runaway real-time process from freezing the system was to "
"run (at the console)  a shell scheduled under a higher static priority than "
"the tested application.  This allows an emergency kill of tested real-time "
"applications that do not block or terminate as expected."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 2.6.25, there are other techniques for dealing with runaway real-"
"time and deadline processes.  One of these is to use the B<RLIMIT_RTTIME> "
"resource limit to set a ceiling on the CPU time that a real-time process may "
"consume.  See B<getrlimit>(2)  for details."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 2.6.25, Linux also provides two I</proc> files that can be used "
"to reserve a certain amount of CPU time to be used by non-real-time "
"processes.  Reserving CPU time in this fashion allows some CPU time to be "
"allocated to (say) a root shell that can be used to kill a runaway process.  "
"Both of these files specify time values in microseconds:"
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "I</proc/sys/kernel/sched_rt_period_us>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This file specifies a scheduling period that is equivalent to 100% CPU "
"bandwidth.  The value in this file can range from 1 to B<INT_MAX>, giving an "
"operating range of 1 microsecond to around 35 minutes.  The default value in "
"this file is 1,000,000 (1 second)."
msgstr ""

#. type: TP
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "I</proc/sys/kernel/sched_rt_runtime_us>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The value in this file specifies how much of the \"period\" time can be used "
"by all real-time and deadline scheduled processes on the system.  The value "
"in this file can range from -1 to B<INT_MAX>-1.  Specifying -1 makes the run "
"time the same as the period; that is, no CPU time is set aside for non-real-"
"time processes (which was the behavior before Linux 2.6.25).  The default "
"value in this file is 950,000 (0.95 seconds), meaning that 5% of the CPU "
"time is reserved for processes that don't run under a real-time or deadline "
"scheduling policy."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Response time"
msgstr ""

#.  as described in
#.  .BR request_irq (9).
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A blocked high priority thread waiting for I/O has a certain response time "
"before it is scheduled again.  The device driver writer can greatly reduce "
"this response time by using a \"slow interrupt\" interrupt handler."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Miscellaneous"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Child processes inherit the scheduling policy and parameters across a "
"B<fork>(2).  The scheduling policy and parameters are preserved across "
"B<execve>(2)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Memory locking is usually needed for real-time processes to avoid paging "
"delays; this can be done with B<mlock>(2)  or B<mlockall>(2)."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "The autogroup feature"
msgstr ""

#.  commit 5091faa449ee0b7d73bc296a93bca9540fc51d0a
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 2.6.38, the kernel provides a feature known as autogrouping to "
"improve interactive desktop performance in the face of multiprocess, CPU-"
"intensive workloads such as building the Linux kernel with large numbers of "
"parallel build processes (i.e., the B<make>(1)  B<-j> flag)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This feature operates in conjunction with the CFS scheduler and requires a "
"kernel that is configured with B<CONFIG_SCHED_AUTOGROUP>.  On a running "
"system, this feature is enabled or disabled via the file I</proc/sys/kernel/"
"sched_autogroup_enabled>; a value of 0 disables the feature, while a value "
"of 1 enables it.  The default value in this file is 1, unless the kernel was "
"booted with the I<noautogroup> parameter."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A new autogroup is created when a new session is created via B<setsid>(2); "
"this happens, for example, when a new terminal window is started.  A new "
"process created by B<fork>(2)  inherits its parent's autogroup membership.  "
"Thus, all of the processes in a session are members of the same autogroup.  "
"An autogroup is automatically destroyed when the last process in the group "
"terminates."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"When autogrouping is enabled, all of the members of an autogroup are placed "
"in the same kernel scheduler \"task group\".  The CFS scheduler employs an "
"algorithm that equalizes the distribution of CPU cycles across task groups.  "
"The benefits of this for interactive desktop performance can be described "
"via the following example."
msgstr ""

#.  Mike Galbraith, 25 Nov 2016:
#.      I'd say something more wishy-washy here, like cycles are
#.      distributed fairly across groups and leave it at that, as your
#.      detailed example is incorrect due to SMP fairness (which I don't
#.      like much because [very unlikely] worst case scenario
#.      renders a box sized group incapable of utilizing more that
#.      a single CPU total).  For example, if a group of NR_CPUS
#.      size competes with a singleton, load balancing will try to give
#.      the singleton a full CPU of its very own.  If groups intersect for
#.      whatever reason on say my quad lappy, distribution is 80/20 in
#.      favor of the singleton.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Suppose that there are two autogroups competing for the same CPU (i.e., "
"presume either a single CPU system or the use of B<taskset>(1)  to confine "
"all the processes to the same CPU on an SMP system).  The first group "
"contains ten CPU-bound processes from a kernel build started with I<make\\~-"
"j10>.  The other contains a single CPU-bound process: a video player.  The "
"effect of autogrouping is that the two groups will each receive half of the "
"CPU cycles.  That is, the video player will receive 50% of the CPU cycles, "
"rather than just 9% of the cycles, which would likely lead to degraded video "
"playback.  The situation on an SMP system is more complex, but the general "
"effect is the same: the scheduler distributes CPU cycles across task groups "
"such that an autogroup that contains a large number of CPU-bound processes "
"does not end up hogging CPU cycles at the expense of the other jobs on the "
"system."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"A process's autogroup (task group) membership can be viewed via the file I</"
"proc/>pidI</autogroup>:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid ""
"$ B<cat /proc/1/autogroup>\n"
"/autogroup-1 nice 0\n"
msgstr ""

#
#.  FIXME .
#.  Because of a bug introduced in Linux 4.7
#.  (commit 2159197d66770ec01f75c93fb11dc66df81fd45b made changes
#.  that exposed the fact that autogroup didn't call scale_load()),
#.  it happened that *all* values in this range caused a task group
#.  to be further disfavored by the scheduler, with \-20 resulting
#.  in the scheduler mildly disfavoring the task group and +19 greatly
#.  disfavoring it.
#.  A patch was posted on 23 Nov 2016
#.  ("sched/autogroup: Fix 64bit kernel nice adjustment";
#.  check later to see in which kernel version it lands.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"This file can also be used to modify the CPU bandwidth allocated to an "
"autogroup.  This is done by writing a number in the \"nice\" range to the "
"file to set the autogroup's nice value.  The allowed range is from +19 (low "
"priority) to -20 (high priority).  (Writing values outside of this range "
"causes B<write>(2)  to fail with the error B<EINVAL>.)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The autogroup nice setting has the same meaning as the process nice value, "
"but applies to distribution of CPU cycles to the autogroup as a whole, based "
"on the relative nice values of other autogroups.  For a process inside an "
"autogroup, the CPU cycles that it receives will be a product of the "
"autogroup's nice value (compared to other autogroups)  and the process's "
"nice value (compared to other processes in the same autogroup."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The use of the B<cgroups>(7)  CPU controller to place processes in cgroups "
"other than the root CPU cgroup overrides the effect of autogrouping."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The autogroup feature groups only processes scheduled under non-real-time "
"policies (B<SCHED_OTHER>, B<SCHED_BATCH>, and B<SCHED_IDLE>).  It does not "
"group processes scheduled under real-time and deadline policies.  Those "
"processes are scheduled according to the rules described earlier."
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "The nice value and group scheduling"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"When scheduling non-real-time processes (i.e., those scheduled under the "
"B<SCHED_OTHER>, B<SCHED_BATCH>, and B<SCHED_IDLE> policies), the CFS "
"scheduler employs a technique known as \"group scheduling\", if the kernel "
"was configured with the B<CONFIG_FAIR_GROUP_SCHED> option (which is typical)."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Under group scheduling, threads are scheduled in \"task groups\".  Task "
"groups have a hierarchical relationship, rooted under the initial task group "
"on the system, known as the \"root task group\".  Task groups are formed in "
"the following circumstances:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"All of the threads in a CPU cgroup form a task group.  The parent of this "
"task group is the task group of the corresponding parent cgroup."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If autogrouping is enabled, then all of the threads that are (implicitly) "
"placed in an autogroup (i.e., the same session, as created by B<setsid>(2))  "
"form a task group.  Each new autogroup is thus a separate task group.  The "
"root task group is the parent of all such autogroups."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If autogrouping is enabled, then the root task group consists of all "
"processes in the root CPU cgroup that were not otherwise implicitly placed "
"into a new autogroup."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If autogrouping is disabled, then the root task group consists of all "
"processes in the root CPU cgroup."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"If group scheduling was disabled (i.e., the kernel was configured without "
"B<CONFIG_FAIR_GROUP_SCHED>), then all of the processes on the system are "
"notionally placed in a single task group."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Under group scheduling, a thread's nice value has an effect for scheduling "
"decisions I<only relative to other threads in the same task group>.  This "
"has some surprising consequences in terms of the traditional semantics of "
"the nice value on UNIX systems.  In particular, if autogrouping is enabled "
"(which is the default in various distributions), then employing "
"B<setpriority>(2)  or B<nice>(1)  on a process has an effect only for "
"scheduling relative to other processes executed in the same session "
"(typically: the same terminal window)."
msgstr ""

#.  More succinctly: the nice(1) command is in many cases a no-op since
#.  Linux 2.6.38.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Conversely, for two processes that are (for example)  the sole CPU-bound "
"processes in different sessions (e.g., different terminal windows, each of "
"whose jobs are tied to different autogroups), I<modifying the nice value of "
"the process in one of the sessions> I<has no effect> in terms of the "
"scheduler's decisions relative to the process in the other session.  A "
"possibly useful workaround here is to use a command such as the following to "
"modify the autogroup nice value for I<all> of the processes in a terminal "
"session:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "$ B<echo 10 E<gt> /proc/self/autogroup>\n"
msgstr ""

#. type: SS
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "Real-time features in the mainline Linux kernel"
msgstr ""

#.  FIXME . Probably this text will need some minor tweaking
#.  ask Carsten Emde about this.
#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Since Linux 2.6.18, Linux is gradually becoming equipped with real-time "
"capabilities, most of which are derived from the former I<realtime-preempt> "
"patch set.  Until the patches have been completely merged into the mainline "
"kernel, they must be installed to achieve the best real-time performance.  "
"These patches are named:"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "patch-I<kernelversion>-rtI<patchversion>\n"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"and can be downloaded from E<.UR http://www.kernel.org\\:/pub\\:/linux\\:/"
"kernel\\:/projects\\:/rt/> E<.UE .>"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Without the patches and prior to their full inclusion into the mainline "
"kernel, the kernel configuration offers only the three preemption classes "
"B<CONFIG_PREEMPT_NONE>, B<CONFIG_PREEMPT_VOLUNTARY>, and "
"B<CONFIG_PREEMPT_DESKTOP> which respectively provide no, some, and "
"considerable reduction of the worst-case scheduling latency."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"With the patches applied or after their full inclusion into the mainline "
"kernel, the additional configuration item B<CONFIG_PREEMPT_RT> becomes "
"available.  If this is selected, Linux is transformed into a regular real-"
"time operating system.  The FIFO and RR scheduling policies are then used to "
"run a thread with true real-time priority and a minimum worst-case "
"scheduling latency."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "NOTES"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The B<cgroups>(7)  CPU controller can be used to limit the CPU consumption "
"of groups of processes."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"Originally, Standard Linux was intended as a general-purpose operating "
"system being able to handle background processes, interactive applications, "
"and less demanding real-time applications (applications that need to usually "
"meet timing deadlines).  Although the Linux 2.6 allowed for kernel "
"preemption and the newly introduced O(1) scheduler ensures that the time "
"needed to schedule is fixed and deterministic irrespective of the number of "
"active tasks, true real-time computing was not possible up to Linux 2.6.17."
msgstr ""

#. type: SH
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "SEE ALSO"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"B<chcpu>(1), B<chrt>(1), B<lscpu>(1), B<ps>(1), B<taskset>(1), B<top>(1), "
"B<getpriority>(2), B<mlock>(2), B<mlockall>(2), B<munlock>(2), "
"B<munlockall>(2), B<nice>(2), B<sched_get_priority_max>(2), "
"B<sched_get_priority_min>(2), B<sched_getaffinity>(2), B<sched_getparam>(2), "
"B<sched_getscheduler>(2), B<sched_rr_get_interval>(2), "
"B<sched_setaffinity>(2), B<sched_setparam>(2), B<sched_setscheduler>(2), "
"B<sched_yield>(2), B<setpriority>(2), B<pthread_getaffinity_np>(3), "
"B<pthread_getschedparam>(3), B<pthread_setaffinity_np>(3), "
"B<sched_getcpu>(3), B<capabilities>(7), B<cpuset>(7)"
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"I<Programming for the real world - POSIX.4> by Bill O.\\& Gallmeister, "
"O'Reilly & Associates, Inc., ISBN 1-56592-074-0."
msgstr ""

#. type: Plain text
#: archlinux debian-bookworm debian-unstable fedora-40 fedora-rawhide
#: mageia-cauldron opensuse-leap-15-6 opensuse-tumbleweed
msgid ""
"The Linux kernel source files I<\\%Documentation/\\:scheduler/\\:sched-"
"deadline\\:.txt>, I<\\%Documentation/\\:scheduler/\\:sched-rt-group\\:.txt>, "
"I<\\%Documentation/\\:scheduler/\\:sched-design-CFS\\:.txt>, and I<\\"
"%Documentation/\\:scheduler/\\:sched-nice-design\\:.txt>"
msgstr ""

#. type: TH
#: debian-bookworm debian-unstable opensuse-leap-15-6 opensuse-tumbleweed
#, no-wrap
msgid "2023-02-10"
msgstr ""

#. type: TH
#: debian-bookworm
#, no-wrap
msgid "Linux man-pages 6.03"
msgstr ""

#. type: TH
#: debian-unstable opensuse-tumbleweed
#, no-wrap
msgid "Linux man-pages 6.05.01"
msgstr ""

#. type: TH
#: opensuse-leap-15-6
#, no-wrap
msgid "Linux man-pages 6.04"
msgstr ""