--- /dev/null
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd-daemon">
+
+ <refentryinfo>
+ <title>sd-readahead</title>
+ <productname>systemd</productname>
+
+ <authorgroup>
+ <author>
+ <contrib>Developer</contrib>
+ <firstname>Lennart</firstname>
+ <surname>Poettering</surname>
+ <email>lennart@poettering.net</email>
+ </author>
+ </authorgroup>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>sd-readahead</refentrytitle>
+ <manvolnum>7</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd-readahead</refname>
+ <refpurpose>Reference implementation of APIs for
+ controlling boot-time read-ahead</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include "sd-readahead.h"</funcsynopsisinfo>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><filename>sd-readahead.c</filename> and
+ <filename>sd-readahead.h</filename> provide a
+ reference implementation for APIs for controlling boot-time
+ read-ahead, as implemented by the read-ahead subsystem
+ of the
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ init system.</para>
+
+ <para>See
+ <citerefentry><refentrytitle>sd_readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for more information about the function
+ implemented.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>This interface is provided by the reference
+ implementation of APIs for controlling boot-time
+ read-ahead and distributed with the systemd
+ package. The algorithms it implements are simple, and
+ can easily be reimplemented in daemons if it is
+ important to support this interface without using the
+ reference implementation. See the respective function
+ man pages for details.</para>
+
+ <para>In addition, for details about the algorithms
+ check the liberally licensed reference implementation
+ sources:
+ <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-readahead.c"/>
+ resp. <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-readahead.h"/></para>
+
+ <para>These APIs are implemented in the reference
+ implementation's drop-in
+ <filename>sd-readahead.c</filename> and
+ <filename>sd-readahead.h</filename> files. It is
+ recommended that applications consuming these APIs copy
+ the implementation into their source tree, either
+ verbatim or in excerpts. These interfaces are
+ currently not available in a dynamic library.</para>
+
+ <para>The functions provided by this interface become
+ NOPs when -DDISABLE_SYSTEMD is set during
+ compilation. In addition, if
+ <filename>sd-readhead.c</filename> is compiled on
+ non-Linux systems it becomes NOPs.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
<refnamediv>
<refname>sd_readahead</refname>
- <refpurpose>Control ongoing disk read-ahead operations</refpurpose>
+ <refpurpose>Control ongoing disk boot-time read-ahead operations</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Description</title>
<para><function>sd_readahead()</function> may be
called by programs involved with early boot-up to
- control ongoing disk read-ahead operations. It may be
+ control ongoing boot-time disk read-ahead operations. It may be
used to terminate read-ahead operations in case an
uncommon disk access pattern is to be expected and
hence read-ahead replay or collection is unlikely to
<title>Notes</title>
<para>This function is provided by the reference
- implementation of APIs for new-style daemons and
- distributed with the systemd package. The algorithm
- it implements is simple, and can easily be
- reimplemented in daemons if it is important to support
- this interface without using the reference
- implementation.</para>
+ implementation of APIs for controlling boot-time
+ read-ahead and distributed with the systemd
+ package. The algorithm it implements is simple, and
+ can easily be reimplemented in daemons if it is
+ important to support this interface without using the
+ reference implementation.</para>
<para>Internally, this function creates a file in
<filename>/dev/.systemd/readahead/</filename> which is
<para>For details about the algorithm check the
liberally licensed reference implementation sources:
- <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
+ <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-readahead.c"/>
resp. <ulink
- url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
+ url="http://cgit.freedesktop.org/systemd/tree/src/sd-readahead.h"/></para>
<para><function>sd_readahead()</function> is
implemented in the reference implementation's drop-in
- <filename>sd-daemon.c</filename> and
- <filename>sd-daemon.h</filename> files. It is
+ <filename>sd-readahead.c</filename> and
+ <filename>sd-readahead.h</filename> files. It is
recommended that applications consuming this API copy
the implementation into their source tree. For more
details about the reference implementation see
- <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>
+ <citerefentry><refentrytitle>sd-readahead</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>
<para>If -DDISABLE_SYSTEMD is set during compilation
this function will always return 0 and otherwise
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd-readahead</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / commitdiff