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diff --git a/man/sd_readahead.xml b/man/sd_readahead.xml deleted file mode 100644 index 98272997c..000000000 --- a/man/sd_readahead.xml +++ /dev/null @@ -1,178 +0,0 @@ -<?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 Lesser General Public License as published by - the Free Software Foundation; either version 2.1 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="sd_readahead" conditional='ENABLE_READAHEAD'> - - <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>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_readahead</refname> - <refpurpose>Control ongoing disk boot-time read-ahead operations</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include "sd-readahead.h"</funcsynopsisinfo> - - <funcprototype> - <funcdef>int <function>sd_readahead</function></funcdef> - <paramdef>const char *<parameter>action</parameter></paramdef> - </funcprototype> - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - <para><function>sd_readahead()</function> may be - called by programs involved with early boot-up to - 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 - have the desired speed-up effect on the current or - future boot-ups.</para> - - <para>The <parameter>action</parameter> should be one - of the following strings:</para> - - <variablelist> - <varlistentry> - <term>cancel</term> - - <listitem><para>Terminates read-ahead - data collection, and drops all - read-ahead data collected during this - boot-up.</para></listitem> - </varlistentry> - - <varlistentry> - <term>done</term> - - <listitem><para>Terminates read-ahead - data collection, but keeps all - read-ahead data collected during this - boot-up around for use during - subsequent boot-ups.</para></listitem> - </varlistentry> - - <varlistentry> - <term>noreplay</term> - - <listitem><para>Terminates read-ahead - replay.</para></listitem> - </varlistentry> - - </variablelist> - - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>On failure, these calls return a negative - errno-style error code. It is generally recommended to - ignore the return value of this call.</para> - </refsect1> - - <refsect1> - <title>Notes</title> - - <para>This function is provided by the reference - 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>/run/systemd/readahead/</filename> which is - then used as flag file to notify the read-ahead - subsystem.</para> - - <para>For details about the algorithm check the - liberally licensed reference implementation sources: - <ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/readahead/sd-readahead.c"/> - and <ulink - url="http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-readahead.h"/></para> - - <para><function>sd_readahead()</function> is - 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 this API copy - the implementation into their source tree. For more - details about the reference implementation, see - <citerefentry><refentrytitle>sd-readahead</refentrytitle><manvolnum>3</manvolnum></citerefentry></para> - - <para>If -DDISABLE_SYSTEMD is set during compilation, - this function will always return 0 and otherwise - become a NOP.</para> - </refsect1> - - <refsect1> - <title>Examples</title> - - <example> - <title>Cancelling all read-ahead operations</title> - - <para>During boots where SELinux has to - relabel the file system hierarchy, it will - create a large amount of disk accesses that - are not necessary during normal boots. Hence - it is a good idea to disable both read-ahead replay and read-ahead collection. - </para> - - <programlisting>sd_readahead("cancel"); -sd_readahead("noreplay");</programlisting> - </example> - - </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>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |