chiark / gitweb /
timer: implement calendar time events
[elogind.git] / man / sd-readahead.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4
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8   Copyright 2010 Lennart Poettering
9
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23
24 <refentry id="sd-daemon">
25
26         <refentryinfo>
27                 <title>sd-readahead</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>sd-readahead</refentrytitle>
42                 <manvolnum>3</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>sd-readahead</refname>
47                 <refpurpose>Reference implementation of APIs for
48                 controlling boot-time read-ahead</refpurpose>
49         </refnamediv>
50
51         <refsynopsisdiv>
52                 <funcsynopsis>
53                         <funcsynopsisinfo>#include "sd-readahead.h"</funcsynopsisinfo>
54                 </funcsynopsis>
55         </refsynopsisdiv>
56
57         <refsect1>
58                 <title>Description</title>
59
60                 <para><filename>sd-readahead.c</filename> and
61                 <filename>sd-readahead.h</filename> provide a
62                 reference implementation for APIs for controlling boot-time
63                 read-ahead, as implemented by the read-ahead subsystem
64                 of the
65                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
66                 init system.</para>
67
68                 <para>See
69                 <citerefentry><refentrytitle>sd_readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry>
70                 for more information about the function
71                 implemented.</para>
72         </refsect1>
73
74         <refsect1>
75                 <title>Notes</title>
76
77                 <para>This interface is provided by the reference
78                 implementation of APIs for controlling boot-time
79                 read-ahead and distributed with the systemd
80                 package. The algorithms it implements are simple, and
81                 can easily be reimplemented in daemons if it is
82                 important to support this interface without using the
83                 reference implementation. See the respective function
84                 man pages for details.</para>
85
86                 <para>In addition, for details about the algorithms
87                 check the liberally licensed reference implementation
88                 sources:
89                 <ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/readahead/sd-readahead.c"/>
90                 and <ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-readahead.h"/></para>
91
92                 <para>These APIs are implemented in the reference
93                 implementation's drop-in
94                 <filename>sd-readahead.c</filename> and
95                 <filename>sd-readahead.h</filename> files. It is
96                 recommended that applications consuming these APIs copy
97                 the implementation into their source tree, either
98                 verbatim or in excerpts. These interfaces are
99                 currently not available in a dynamic library.</para>
100
101                 <para>The functions provided by this interface become
102                 NOPs when -DDISABLE_SYSTEMD is set during
103                 compilation. In addition, if
104                 <filename>sd-readhead.c</filename> is compiled on
105                 non-Linux systems it becomes NOPs.</para>
106         </refsect1>
107
108         <refsect1>
109                 <title>See Also</title>
110                 <para>
111                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
112                         <citerefentry><refentrytitle>sd_readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
113                         <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>
114                 </para>
115         </refsect1>
116
117 </refentry>