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1 | <?xml version='1.0'?> |
2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" | |
3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> | |
4 | <!-- SPDX-License-Identifier: LGPL-2.1+ --> | |
5 | ||
6 | <refentry id="systemd-udev-settle.service" | |
7 | xmlns:xi="http://www.w3.org/2001/XInclude"> | |
8 | ||
9 | <refentryinfo> | |
10 | <title>systemd-udev-settle.service</title> | |
11 | <productname>systemd</productname> | |
12 | </refentryinfo> | |
13 | ||
14 | <refmeta> | |
15 | <refentrytitle>systemd-udev-settle.service</refentrytitle> | |
16 | <manvolnum>8</manvolnum> | |
17 | </refmeta> | |
18 | ||
19 | <refnamediv> | |
20 | <refname>systemd-udev-settle.service</refname> | |
21 | <refpurpose>Wait for all pending udev events to be handled</refpurpose> | |
22 | </refnamediv> | |
23 | ||
24 | <refsynopsisdiv> | |
25 | <para><filename>systemd-udev-settle.service</filename></para> | |
26 | </refsynopsisdiv> | |
27 | ||
28 | <refsect1><title>Description</title> | |
29 | <para>This service calls <command>udevadm settle</command> to wait until all events that have been queued | |
30 | by <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry> have been | |
31 | processed. It is a crude way to wait until "all" hardware has been discovered. Services may pull in this | |
32 | service and order themselves after it to wait for the udev queue to be empty.</para> | |
33 | ||
34 | <para><emphasis>Using this service is not recommended.</emphasis> There can be no guarantee that hardware | |
35 | is fully discovered at any specific time, because the kernel does hardware detection asynchronously, and | |
5238e957 | 36 | certain buses and devices take a very long time to become ready, and also additional hardware may be |
18a38822 ZJS |
37 | plugged in at any time. Instead, services should subscribe to udev events and react to any new hardware as |
38 | it is discovered. Services that, based on configuration, expect certain devices to appear, may warn or | |
39 | report failure after a timeout. This timeout should be tailored to the hardware type. Waiting for | |
40 | <filename>systemd-udev-settle.service</filename> usually slows boot significantly, because it means waiting | |
41 | for all unrelated events too.</para> | |
42 | </refsect1> | |
43 | ||
44 | <refsect1> | |
45 | <title>See Also</title> | |
46 | <para> | |
47 | <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
48 | <citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
49 | </para> | |
50 | </refsect1> | |
51 | </refentry> |