unit skip/fail activation if the system's (or a slice's) memory/cpu/io
pressure is above the configured threshold, using the kernel PSI
feature. For more details see systemd.unit(5) and
- https://www.kernel.org/doc/html/latest/accounting/psi.html
+ https://docs.kernel.org/accounting/psi.html
* The combination of ProcSubset=pid and ProtectKernelTunables=yes and/or
ProtectKernelLogs=yes can now be used.
a client with a Wi-Fi and Ethernet both connected to the internet).
Consult the kernel documentation for details on this sysctl:
- https://www.kernel.org/doc/html/latest/networking/ip-sysctl.html
+ https://docs.kernel.org/networking/ip-sysctl.html
* The v239 change to turn on "net.ipv4.tcp_ecn" by default has been
reverted.
Before you read on, please make sure you read the low-level kernel
documentation about the
-[unified cgroup hierarchy](https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html).
+[unified cgroup hierarchy](https://docs.kernel.org/admin-guide/cgroup-v2.html).
This document then adds in the higher-level view from systemd.
This document augments the existing documentation we already have:
# the continued use of devices after a power loss (due to suspend). Disable it
# if the device will loose state without a USB power session and the driver
# is unable to recover the state when resuming. See
-# https://www.kernel.org/doc/html/latest/driver-api/usb/persist.html
+# https://docs.kernel.org/driver-api/usb/persist.html
# Sort by brand, model
<title>Configuration Format</title>
<para>Each file contains a list of binfmt_misc kernel binary format rules. Consult the kernel's <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html">Kernel Support for
+ url="https://docs.kernel.org/admin-guide/binfmt-misc.html">Kernel Support for
miscellaneous Binary Formats (binfmt_misc)</ulink> documentation file for more information on
registration of additional binary formats and how to write rules.</para>
<para>For command line parameters understood by the kernel, please
see
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html"><filename>kernel-parameters.html</filename></ulink>
+ <ulink url="https://docs.kernel.org/admin-guide/kernel-parameters.html"><filename>kernel-parameters.html</filename></ulink>
and
<citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
<title><filename>/etc/initrd-release</filename></title>
<para>In the <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/initrd.html">initrd</ulink>,
+ url="https://docs.kernel.org/admin-guide/initrd.html">initrd</ulink>,
<filename>/etc/initrd-release</filename> plays the same role as <filename>os-release</filename> in the
main system. Additionally, the presence of that file means that the system is in the initrd phase.
<filename>/etc/os-release</filename> should be symlinked to <filename>/etc/initrd-release</filename>
<listitem><para>A lower-case string (mostly numeric, no spaces or other characters outside of 0–9,
a–z, ".", "_" and "-") identifying the operating system extensions support level, to indicate which
extension images are supported. See <filename>/usr/lib/extension-release.d/extension-release.<replaceable>IMAGE</replaceable></filename>,
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/initrd.html">initrd</ulink> and
+ <ulink url="https://docs.kernel.org/admin-guide/initrd.html">initrd</ulink> and
<citerefentry><refentrytitle>systemd-sysext</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
for more information.</para>
<para>This file configures the behavior of
<citerefentry><refentrytitle>systemd-pstore</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
a tool for archiving the contents of the persistent storage filesystem,
- <ulink url="https://www.kernel.org/doc/Documentation/ABI/testing/pstore">pstore</ulink>.
+ <ulink url="https://docs.kernel.org/admin-guide/abi-testing.html#abi-sys-fs-pstore">pstore</ulink>.
</para>
</refsect1>
<para><function>sd_bus_creds_get_cgroup()</function> will retrieve
the control group path. See <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/index.html">Control Groups version 1</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/index.html">Control Groups version 1</ulink>.
</para>
<para><function>sd_bus_creds_get_unit()</function> will retrieve
place, regardless of which environment the system is started in. For example, it is sufficient to
redirect the kernel console with a kernel command line argument such as <varname>console=</varname> to
get both kernel messages and a getty prompt on a serial TTY. See <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html">The kernel's command-line
+ url="https://docs.kernel.org/admin-guide/kernel-parameters.html">The kernel's command-line
parameters</ulink> for more information on the <varname>console=</varname> kernel parameter.</para>
<para><filename>systemd-getty-generator</filename> implements
<para><filename>systemd-hibernate-resume</filename> only supports
the in-kernel hibernation implementation, see
- <ulink url="https://www.kernel.org/doc/html/latest/power/swsusp.html">Swap suspend</ulink>.
+ <ulink url="https://docs.kernel.org/power/swsusp.html">Swap suspend</ulink>.
Internally, it works by writing the major:minor of specified
device node to <filename>/sys/power/resume</filename>.</para>
<replaceable>device</replaceable>. See
<citerefentry><refentrytitle>integritytab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
and
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/dm-integrity.html">
+ <ulink url="https://docs.kernel.org/admin-guide/device-mapper/dm-integrity.html">
Kernel dm-integrity</ulink> documentation for details.
</para></listitem>
</varlistentry>
temporary directory on a read-only <filename>/var/</filename> directory.</para>
<para>For details about overlay file systems, see <ulink
- url="https://www.kernel.org/doc/html/latest/filesystems/overlayfs.html">Overlay Filesystem</ulink>.
+ url="https://docs.kernel.org/filesystems/overlayfs.html">Overlay Filesystem</ulink>.
Note that the semantics of overlay file systems are substantially different from normal file systems,
in particular regarding reported device and inode information. Device and inode information may
change for a file while it is being written to, and processes might see out-of-date versions of files
on executables with setuid or setgid bits and will thus not
function properly with this option enabled. Individual units
cannot disable this option.
- Also see <ulink url="https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>.
+ Also see <ulink url="https://docs.kernel.org/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>.
</para></listitem>
</varlistentry>
<replaceable>datadevice</replaceable> and <replaceable>hashdevice</replaceable> as the backing
devices. <replaceable>roothash</replaceable> forms the root of the tree of hashes stored on
<replaceable>hashdevice</replaceable>. See
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/verity.html">
+ <ulink url="https://docs.kernel.org/admin-guide/device-mapper/verity.html">
Kernel dm-verity</ulink> documentation for details.
</para></listitem>
</varlistentry>
<filename>/proc/</filename>. If <literal>ptraceable</literal> all processes that cannot be
<function>ptrace()</function>'ed by a process are hidden to it. If <literal>default</literal> no
restrictions on <filename>/proc/</filename> access or visibility are made. For further details see
- <ulink url="https://www.kernel.org/doc/html/latest/filesystems/proc.html#mount-options">The /proc
+ <ulink url="https://docs.kernel.org/filesystems/proc.html#mount-options">The /proc
Filesystem</ulink>. It is generally recommended to run most system services with this option set to
<literal>invisible</literal>. This option is implemented via file system namespacing, and thus cannot
be used with services that shall be able to install mount points in the host file system
introspection are made invisible in the <filename>/proc/</filename> file system configured for the
unit's processes. This controls the <literal>subset=</literal> mount option of the
<literal>procfs</literal> instance for the unit. For further details see <ulink
- url="https://www.kernel.org/doc/html/latest/filesystems/proc.html#mount-options">The /proc
+ url="https://docs.kernel.org/filesystems/proc.html#mount-options">The /proc
Filesystem</ulink>. Note that Linux exposes various kernel APIs via <filename>/proc/</filename>,
which are made unavailable with this setting. Since these APIs are used frequently this option is
useful only in a few, specific cases, and is not suitable for most non-trivial programs.</para>
by them, <command>systemctl show</command> shows the original value of this setting. In case the
service will be run in a new mount namespace anyway and SELinux is disabled, all file systems
are mounted with <constant>MS_NOSUID</constant> flag. Also see
- <ulink url="https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html">No New
+ <ulink url="https://docs.kernel.org/userspace-api/no_new_privs.html">No New
Privileges Flag</ulink>.</para></listitem>
</varlistentry>
<listitem><para>Sets the adjustment value for the Linux kernel's Out-Of-Memory (OOM) killer score for
executed processes. Takes an integer between -1000 (to disable OOM killing of processes of this unit)
and 1000 (to make killing of processes of this unit under memory pressure very likely). See <ulink
- url="https://www.kernel.org/doc/html/latest/filesystems/proc.html">The /proc Filesystem</ulink> for
+ url="https://docs.kernel.org/filesystems/proc.html">The /proc Filesystem</ulink> for
details. If not specified defaults to the OOM score adjustment level of the service manager itself,
which is normally at 0.</para>
</row></thead>
<tbody>
<row><entry><varname>bond</varname></entry>
- <entry>A bond device is an aggregation of all its slave devices. See <ulink url="https://www.kernel.org/doc/html/latest/networking/bonding.html">Linux Ethernet Bonding Driver HOWTO</ulink> for details.</entry></row>
+ <entry>A bond device is an aggregation of all its slave devices. See <ulink url="https://docs.kernel.org/networking/bonding.html">Linux Ethernet Bonding Driver HOWTO</ulink> for details.</entry></row>
<row><entry><varname>bridge</varname></entry>
<entry>A bridge device is a software switch, and each of its slave devices and the bridge itself are ports of the switch.</entry></row>
<entry>Media Access Control Security (MACsec) is an 802.1AE IEEE industry-standard security technology that provides secure communication for all traffic on Ethernet links. MACsec provides point-to-point security on Ethernet links between directly connected nodes and is capable of identifying and preventing most security threats.</entry></row>
<row><entry><varname>vrf</varname></entry>
- <entry>A Virtual Routing and Forwarding (<ulink url="https://www.kernel.org/doc/html/latest/networking/vrf.html">VRF</ulink>) interface to create separate routing and forwarding domains.</entry></row>
+ <entry>A Virtual Routing and Forwarding (<ulink url="https://docs.kernel.org/networking/vrf.html">VRF</ulink>) interface to create separate routing and forwarding domains.</entry></row>
<row><entry><varname>vcan</varname></entry>
<entry>The virtual CAN driver (vcan). Similar to the network loopback devices, vcan offers a virtual local CAN interface.</entry></row>
</variablelist>
<para>For more detail information see
- <ulink url="https://www.kernel.org/doc/html/latest/networking/bonding.html">
+ <ulink url="https://docs.kernel.org/networking/bonding.html">
Linux Ethernet Bonding Driver HOWTO</ulink></para>
</refsect1>
enable IP packet forwarding for the specified address family. This controls the
<filename>net.ipv4.ip_forward</filename> and <filename>net.ipv6.conf.all.forwarding</filename>
sysctl options of the network interface (see
- <ulink url="https://www.kernel.org/doc/html/latest/networking/ip-sysctl.html">IP Sysctl</ulink>
+ <ulink url="https://docs.kernel.org/networking/ip-sysctl.html">IP Sysctl</ulink>
for details about sysctl options). Defaults to <literal>no</literal>.</para>
<para>Note: this setting controls a global kernel option, and does so one way only: if a
section, see below.</para>
<para>Also see
- <ulink url="https://www.kernel.org/doc/html/latest/networking/ip-sysctl.html">IP Sysctl</ulink>
+ <ulink url="https://docs.kernel.org/networking/ip-sysctl.html">IP Sysctl</ulink>
in the kernel documentation regarding <literal>accept_ra</literal>, but note that systemd's
setting of <constant>1</constant> (i.e. true) corresponds to kernel's setting of
<constant>2</constant>.</para>
<title>Unified and Legacy Control Group Hierarchies</title>
<para>The unified control group hierarchy is the new version of kernel control group interface, see
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">Control Groups v2</ulink>.
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html">Control Groups v2</ulink>.
Depending on the resource type, there are differences in resource control capabilities. Also, because of
interface changes, some resource types have separate set of options on the unified hierarchy.</para>
application.</para>
<para>Legacy control group hierarchy (see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/">Control Groups version 1</ulink>),
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/">Control Groups version 1</ulink>),
also called cgroup-v1, doesn't allow safe delegation of controllers to unprivileged processes. If the
system uses the legacy control group hierarchy, resource control is disabled for the systemd user
instance, see
hierarchy is used on the system. These options take an integer value and control the
<literal>cpu.weight</literal> control group attribute. The allowed range is 1 to 10000. Defaults to
100. For details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">Control Groups v2</ulink>
- and <ulink url="https://www.kernel.org/doc/html/latest/scheduler/sched-design-CFS.html">CFS
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html">Control Groups v2</ulink>
+ and <ulink url="https://docs.kernel.org/scheduler/sched-design-CFS.html">CFS
Scheduler</ulink>. The available CPU time is split up among all units within one slice relative to
their CPU time weight. A higher weight means more CPU time, a lower weight means less.</para>
available on one CPU. Use values > 100% for allotting CPU time on more than one CPU. This controls the
<literal>cpu.max</literal> attribute on the unified control group hierarchy and
<literal>cpu.cfs_quota_us</literal> on legacy. For details about these control group attributes, see <ulink
- url="https://
www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">Control Groups v2</ulink> and <ulink
- url="https://www.kernel.org/doc/html/latest/scheduler/sched-bwc.html">CFS Bandwidth Control</ulink>.
+ url="https://
docs.kernel.org/admin-guide/cgroup-v2.html">Control Groups v2</ulink> and <ulink
+ url="https://docs.kernel.org/scheduler/sched-bwc.html">CFS Bandwidth Control</ulink>.
Setting <varname>CPUQuota=</varname> to an empty value unsets the quota.</para>
<para>Example: <varname>CPUQuota=20%</varname> ensures that the executed processes will never get more than
<para>This controls the second field of <literal>cpu.max</literal> attribute on the unified control group hierarchy
and <literal>cpu.cfs_period_us</literal> on legacy. For details about these control group attributes, see
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">Control Groups v2</ulink> and
- <ulink url="https://www.kernel.org/doc/html/latest/scheduler/sched-design-CFS.html">CFS Scheduler</ulink>.</para>
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html">Control Groups v2</ulink> and
+ <ulink url="https://docs.kernel.org/scheduler/sched-design-CFS.html">CFS Scheduler</ulink>.</para>
<para>Example: <varname>CPUQuotaPeriodSec=10ms</varname> to request that the CPU quota is measured in periods of 10ms.</para>
</listitem>
useful in order to always inherit all of the protection afforded by ancestors.
This controls the <literal>memory.min</literal> or <literal>memory.low</literal> control group attribute.
For details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
<para>This setting is supported only if the unified control group hierarchy is used and disables
<varname>MemoryLimit=</varname>.</para>
system. If assigned the
special value <literal>infinity</literal>, no memory throttling is applied. This controls the
<literal>memory.high</literal> control group attribute. For details about this control group attribute, see
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
<para>This setting is supported only if the unified control group hierarchy is used and disables
<varname>MemoryLimit=</varname>.</para>
percentage value may be specified, which is taken relative to the installed physical memory on the system. If
assigned the special value <literal>infinity</literal>, no memory limit is applied. This controls the
<literal>memory.max</literal> control group attribute. For details about this control group attribute, see
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
<para>This setting replaces <varname>MemoryLimit=</varname>.</para>
</listitem>
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. If assigned the
special value <literal>infinity</literal>, no swap limit is applied. This controls the
<literal>memory.swap.max</literal> control group attribute. For details about this control group attribute,
- see <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
+ see <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
<para>This setting is supported only if the unified control group hierarchy is used and disables
<varname>MemoryLimit=</varname>.</para>
of tasks or a percentage value that is taken relative to the configured maximum number of tasks on the
system. If assigned the special value <literal>infinity</literal>, no tasks limit is applied. This controls
the <literal>pids.max</literal> control group attribute. For details about this control group attribute, see
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/pids.html">Process Number Controller</ulink>.
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v1/pids.html">Process Number Controller</ulink>.
</para>
<para>The system default for this setting may be controlled with
group hierarchy is used on the system. Takes a single weight value (between 1 and 10000) to set the
default block I/O weight. This controls the <literal>io.weight</literal> control group attribute,
which defaults to 100. For details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#io-interface-files">IO
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html#io-interface-files">IO
Interface Files</ulink>. The available I/O bandwidth is split up among all units within one slice
relative to their block I/O weight. A higher weight means more I/O bandwidth, a lower weight means
less.</para>
device of the file system of the file is determined. This controls the <literal>io.weight</literal> control
group attribute, which defaults to 100. Use this option multiple times to set weights for multiple devices.
For details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.</para>
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.</para>
<para>This setting replaces <varname>BlockIODeviceWeight=</varname> and disables settings prefixed with
<varname>BlockIO</varname> or <varname>StartupBlockIO</varname>.</para>
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M"). This controls the <literal>io.max</literal> control
group attributes. Use this option multiple times to set bandwidth limits for multiple devices. For details
about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.
</para>
<para>These settings replace <varname>BlockIOReadBandwidth=</varname> and
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 1K"). This controls the <literal>io.max</literal> control
group attributes. Use this option multiple times to set IOPS limits for multiple devices. For details about
this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.
</para>
<para>These settings are supported only if the unified control group hierarchy is used and disable settings
system of the file is determined. This controls the <literal>io.latency</literal> control group
attribute. Use this option multiple times to set latency target for multiple devices. For details about this
control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.</para>
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html#io-interface-files">IO Interface Files</ulink>.</para>
<para>Implies <literal>IOAccounting=yes</literal>.</para>
Cgroup-bpf hooks in the form of BPF programs loaded to the BPF filesystem are attached with cgroup-bpf attach
flags determined by the unit. For details about attachment types and flags see <ulink
url="https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/include/uapi/linux/bpf.h"/>.
- For general BPF documentation please refer to <ulink url="https://www.kernel.org/doc/html/latest/bpf/index.html"/>.</para>
+ For general BPF documentation please refer to <ulink url="https://docs.kernel.org/bpf/index.html"/>.</para>
<para>The specification of BPF program consists of a <replaceable>type</replaceable> followed by a
<replaceable>program-path</replaceable> with <literal>:</literal> as the separator:
(<emphasis>m</emphasis>knod), respectively. On cgroup-v1 this controls the
<literal>devices.allow</literal> control group attribute. For details about this control group
attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/devices.html">Device Whitelist Controller</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/devices.html">Device Whitelist Controller</ulink>.
In the unified cgroup hierarchy this functionality is implemented using eBPF filtering.</para>
<para>When access to <emphasis>all</emphasis> physical devices should be disallowed,
<para>Assign the specified CPU time share weight to the processes executed. These options take an integer
value and control the <literal>cpu.shares</literal> control group attribute. The allowed range is 2 to
262144. Defaults to 1024. For details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/scheduler/sched-design-CFS.html">CFS Scheduler</ulink>.
+ url="https://docs.kernel.org/scheduler/sched-design-CFS.html">CFS Scheduler</ulink>.
The available CPU time is split up among all units within one slice relative to their CPU time share
weight.</para>
<literal>infinity</literal>, no memory limit is applied. This controls the
<literal>memory.limit_in_bytes</literal> control group attribute. For details about this control group
attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/memory.html">Memory Resource Controller</ulink>.</para>
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/memory.html">Memory Resource Controller</ulink>.</para>
<para>Implies <literal>MemoryAccounting=yes</literal>.</para>
group hierarchy is used on the system. Takes a single weight value (between 10 and 1000) to set the default
block I/O weight. This controls the <literal>blkio.weight</literal> control group attribute, which defaults to
500. For details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/blkio-controller.html">Block IO Controller</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/blkio-controller.html">Block IO Controller</ulink>.
The available I/O bandwidth is split up among all units within one slice relative to their block I/O
weight.</para>
file system of the file is determined. This controls the <literal>blkio.weight_device</literal> control group
attribute, which defaults to 1000. Use this option multiple times to set weights for multiple devices. For
details about this control group attribute, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/blkio-controller.html">Block IO Controller</ulink>.</para>
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/blkio-controller.html">Block IO Controller</ulink>.</para>
<para>Implies
<literal>BlockIOAccounting=yes</literal>.</para>
<literal>blkio.throttle.read_bps_device</literal> and <literal>blkio.throttle.write_bps_device</literal>
control group attributes. Use this option multiple times to set bandwidth limits for multiple devices. For
details about these control group attributes, see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/blkio-controller.html">Block IO Controller</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/blkio-controller.html">Block IO Controller</ulink>.
</para>
<para>Implies
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-oomd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
The documentation for control groups and specific controllers in the Linux kernel:
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">Control Groups v2</ulink>.
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html">Control Groups v2</ulink>.
</para>
</refsect1>
</refentry>
<term><varname>USBFunctionDescriptors=</varname></term>
<listitem><para>Configure the location of a file containing
<ulink
- url="https://www.kernel.org/doc/html/latest/usb/functionfs.html">USB
+ url="https://docs.kernel.org/usb/functionfs.html">USB
FunctionFS</ulink> descriptors, for implementation of USB
gadget functions. This is used only in conjunction with a
socket unit with <varname>ListenUSBFunction=</varname>
manager. If set to <constant>kill</constant> and one of the service's processes is killed by the OOM
killer the kernel is instructed to kill all remaining processes of the service too, by setting the
<filename>memory.oom.group</filename> attribute to <constant>1</constant>; also see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">kernel documentation</ulink>.
+ url="https://docs.kernel.org/admin-guide/cgroup-v2.html">kernel documentation</ulink>.
</para>
<para>Defaults to the setting <varname>DefaultOOMPolicy=</varname> in
<varlistentry>
<term><varname>ListenUSBFunction=</varname></term>
<listitem><para>Specifies a <ulink
- url="https://www.kernel.org/doc/html/latest/usb/functionfs.html">USB
+ url="https://docs.kernel.org/usb/functionfs.html">USB
FunctionFS</ulink> endpoints location to listen on, for
implementation of USB gadget functions. This expects an
absolute file system path of a FunctionFS mount point as the argument.
the security label of the FIFO, or the security label for the
incoming or outgoing connections of the socket, respectively.
See <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/LSM/Smack.html">Smack</ulink>
+ url="https://docs.kernel.org/admin-guide/LSM/Smack.html">Smack</ulink>
for details.</para></listitem>
</varlistentry>
limited to <literal>10sec</literal>, <literal>1min</literal> and <literal>5min</literal>. The
<literal>full</literal> PSI will be checked first, and if not found <literal>some</literal> will be
checked. For more details, see the documentation on <ulink
- url="https://www.kernel.org/doc/html/latest/accounting/psi.html">PSI (Pressure Stall Information)
+ url="https://docs.kernel.org/accounting/psi.html">PSI (Pressure Stall Information)
</ulink>.</para>
<para>Optionally, the threshold value can be prefixed with the slice unit under which the pressure will be checked,
<para>Processes systemd spawns are placed in individual Linux
control groups named after the unit which they belong to in the
private systemd hierarchy. (see <ulink
- url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/index.html">Control Groups version 1</ulink>
+ url="https://docs.kernel.org/admin-guide/cgroup-v1/index.html">Control Groups version 1</ulink>
for more information about control groups, or short "cgroups").
systemd uses this to effectively keep track of processes. Control
group information is maintained in the kernel, and is accessible
<listitem><para>When specified without an argument or with a true argument,
enables the usage of
- <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html">unified cgroup hierarchy</ulink>
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html">unified cgroup hierarchy</ulink>
(a.k.a. cgroups-v2). When specified with a false argument, fall back to
hybrid or full legacy cgroup hierarchy.</para>
(see previous option). When specified without an argument or with a true
argument, disables the use of "hybrid" cgroup hierarchy (i.e. a cgroups-v2
tree used for systemd, and
- <ulink url="https://www.kernel.org/doc/Documentation/cgroup-v1/">legacy
+ <ulink url="https://docs.kernel.org/admin-guide/cgroup-v1/index.html">legacy
cgroup hierarchy</ulink>, a.k.a. cgroups-v1, for other controllers), and
forces a full "legacy" mode. When specified with a false argument, enables
the use of "hybrid" hierarchy.</para>
/* Serializes one file in the cpio format understood by the kernel initrd logic.
*
- * See: https://www.kernel.org/doc/html/latest/driver-api/early-userspace/buffer-format.html */
+ * See: https://docs.kernel.org/driver-api/early-userspace/buffer-format.html */
if (contents_size > UINT32_MAX) /* cpio cannot deal with > 32bit file sizes */
return EFI_LOAD_ERROR;
* this x86 specific linux_exec function passes the initrd by setting the
* corresponding fields in the setup_header struct.
*
- * see https://www.kernel.org/doc/html/latest/x86/boot.html
+ * see https://docs.kernel.org/x86/boot.html
*/
#include <efi.h>
pid_t pid;
/* libvirt / qemu uses threaded mode and cgroup.procs cannot be read at the lower levels.
- * From https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#threads,
+ * From https://docs.kernel.org/admin-guide/cgroup-v2.html#threads,
* “cgroup.procs” in a threaded domain cgroup contains the PIDs of all processes in
* the subtree and is not readable in the subtree proper. */
r = cg_read_pid(f, &pid);
static void drop_caches_now(void) {
int r;
- /* Drop file system caches now. See https://www.kernel.org/doc/html/latest/admin-guide/sysctl/vm.html
+ /* Drop file system caches now. See https://docs.kernel.org/admin-guide/sysctl/vm.html
* for details. We write "2" into /proc/sys/vm/drop_caches to ensure dentries/inodes are flushed, but
* not more. */
pid_t pid;
/* libvirt / qemu uses threaded mode and cgroup.procs cannot be read at the lower levels.
- * From https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#threads,
+ * From https://docs.kernel.org/admin-guide/cgroup-v2.html#threads,
* “cgroup.procs” in a threaded domain cgroup contains the PIDs of all processes in
* the subtree and is not readable in the subtree proper. */
r = cg_read_pid(f, &pid);
* Verify and load BPF Type Format (BTF) metadata into the kernel,
* returning a new file descriptor associated with the metadata.
* BTF is described in more detail at
- * https://www.kernel.org/doc/html/latest/bpf/btf.html.
+ * https://docs.kernel.org/bpf/btf.html.
*
* The *btf* parameter must point to valid memory providing
* *btf_size* bytes of BTF binary metadata.
assert(device);
/* USB-C power supply device has two power roles: source or sink. See,
- * https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-typec */
+ * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-typec */
r = sd_device_enumerator_new(&e);
if (r < 0)
/* We assume every power source is AC, except for batteries. See
* https://github.com/torvalds/linux/blob/4eef766b7d4d88f0b984781bc1bcb574a6eafdc7/include/linux/power_supply.h#L176
* for defined power source types. Also see:
- * https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-power */
+ * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-power */
if (streq(val, "Battery")) {
log_device_debug(d, "The power supply is battery, ignoring.");
continue;
assert_se(documentation_url_is_valid("https://www.freedesktop.org/wiki/Software/systemd"));
assert_se(documentation_url_is_valid("https://www.kernel.org/doc/Documentation/binfmt_misc.txt")); /* dead */
assert_se(documentation_url_is_valid("https://www.kernel.org/doc/Documentation/admin-guide/binfmt-misc.rst"));
- assert_se(documentation_url_is_valid("https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html"));
+ assert_se(documentation_url_is_valid("https://docs.kernel.org/admin-guide/binfmt-misc.html"));
assert_se(documentation_url_is_valid("file:/foo/foo"));
assert_se(documentation_url_is_valid("man:systemd.special(7)"));
assert_se(documentation_url_is_valid("info:bar"));
# System Request functionality of the kernel (SYNC)
#
# Use kernel.sysrq = 1 to allow all keys.
-# See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html for a list
+# See https://docs.kernel.org/admin-guide/sysrq.html for a list
# of values and keys.
kernel.sysrq = 16
[Unit]
Description=Arbitrary Executable File Formats File System Automount Point
-Documentation=https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html
+Documentation=https://docs.kernel.org/admin-guide/binfmt-misc.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
Before=sysinit.target
[Unit]
Description=Huge Pages File System
-Documentation=https://www.kernel.org/doc/html/latest/admin-guide/mm/hugetlbpage.html
+Documentation=https://docs.kernel.org/admin-guide/mm/hugetlbpage.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
Before=sysinit.target
[Unit]
Description=Arbitrary Executable File Formats File System Automount Point
-Documentation=https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html
+Documentation=https://docs.kernel.org/admin-guide/binfmt-misc.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
Before=sysinit.target
[Unit]
Description=Arbitrary Executable File Formats File System
-Documentation=https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html
+Documentation=https://docs.kernel.org/admin-guide/binfmt-misc.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
[Unit]
Description=FUSE Control File System
-Documentation=https://www.kernel.org/doc/html/latest/filesystems/fuse.html
+Documentation=https://docs.kernel.org/filesystems/fuse.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
ConditionPathExists=/sys/fs/fuse/connections
[Unit]
Description=Kernel Configuration File System
-Documentation=https://www.kernel.org/doc/html/latest/filesystems/configfs.html
+Documentation=https://docs.kernel.org/filesystems/configfs.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
ConditionPathExists=/sys/kernel/config
[Unit]
Description=Kernel Debug File System
-Documentation=https://www.kernel.org/doc/html/latest/filesystems/debugfs.html
+Documentation=https://docs.kernel.org/filesystems/debugfs.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
ConditionPathExists=/sys/kernel/debug
[Unit]
Description=Kernel Trace File System
-Documentation=https://www.kernel.org/doc/html/latest/trace/ftrace.html
+Documentation=https://docs.kernel.org/trace/ftrace.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
ConditionVirtualization=!lxc
[Unit]
Description=Set Up Additional Binary Formats
Documentation=man:systemd-binfmt.service(8) man:binfmt.d(5)
-Documentation=https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html
+Documentation=https://docs.kernel.org/admin-guide/binfmt-misc.html
Documentation=https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
Conflicts=shutdown.target
projects / thirdparty / systemd.git / commitdiff
