+<sect3 renderas="sect4" id="listen-backlog"><title>listen-backlog</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Connection queue length requested from the operating system.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>Number.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>128</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ A connection queue length of 128 is requested from the operating system.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Under high load incoming connection may queue up before Privoxy
+ gets around to serve them. The queue length is limitted by the
+ operating system. Once the queue is full, additional connections
+ are dropped before Privoxy can accept and serve them.
+ </para>
+ <para>
+ Increasing the queue length allows Privoxy to accept more
+ incomming connections that arrive roughly at the same time.
+ </para>
+ <para>
+ Note that Privoxy can only request a certain queue length,
+ whether or not the requested length is actually used depends
+ on the operating system which may use a different length instead.
+ </para>
+ <para>
+ On many operating systems a limit of -1 can be specified to
+ instruct the operating system to use the maximum queue length
+ allowed. Check the listen man page to see if your platform allows this.
+ </para>
+ <para>
+ On some platforms you can use "netstat -Lan -p tcp" to see the effective
+ queue length.
+ </para>
+ <para>
+ Effectively using a value above 128 usually requires changing
+ the system configuration as well. On FreeBSD-based system the
+ limit is controlled by the kern.ipc.soacceptqueue sysctl.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ listen-backlog 4096
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@#listen-backlog -1</literallayout>]]>
+</sect3>
+
+
+<sect3 renderas="sect4" id="enable-accept-filter"><title>enable-accept-filter</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether or not Privoxy should use an accept filter
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>0 or 1</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>0</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ No accept filter is enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Accept filters reduce the number of context switches by not
+ passing sockets for new connections to Privoxy until a complete
+ HTTP request is available.
+ </para>
+ <para>
+ As a result, Privoxy can process the whole request right away
+ without having to wait for additional data first.
+ </para>
+ <para>
+ For this option to work, Privoxy has to be compiled with
+ FEATURE_ACCEPT_FILTER and the operating system has to support
+ it (which may require loading a kernel module).
+ </para>
+ <para>
+ Currently accept filters are only supported on FreeBSD-based
+ systems. Check the
+ <ulink url="https://www.freebsd.org/cgi/man.cgi?query=accf_http">accf_http(9)
+ man page</ulink>
+ to learn how to enable the support in the operating system.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ enable-accept-filter 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@#enable-accept-filter 1</literallayout>]]>
+</sect3>
+
+