System V semaphores are not used on this platform.
       </para>

       <para>
        The default IPC settings can be changed using
        the <command>sysctl</command> or
        <command>loader</command> interfaces.  The following
        parameters can be set using <command>sysctl</command>:
<screen>
<prompt>#</prompt> <userinput>sysctl kern.ipc.shmall=32768</userinput>
<prompt>#</prompt> <userinput>sysctl kern.ipc.shmmax=134217728</userinput>
</screen>
        To make these settings persist over reboots, modify
        <filename>/etc/sysctl.conf</filename>.
       </para>

       <para>
        If you have set <literal>shared_memory_type</literal> to
        <literal>sysv</literal>, you might also want to configure your kernel
        to lock System V shared memory into RAM and prevent it from being paged
        out to swap.  This can be accomplished using the <command>sysctl</command>
        setting <literal>kern.ipc.shm_use_phys</literal>.
       </para>

       <para>
        If running in a FreeBSD jail, you should set its
        <literal>sysvshm</literal> parameter to <literal>new</literal>, so that
        it has its own separate System V shared memory namespace.
        (Before FreeBSD 11.0, it was necessary to enable shared access to
        the host's IPC namespace from jails, and take measures to avoid
        collisions.)
       </para>

      </listitem>
     </varlistentry>

     <varlistentry>
      <term><systemitem class="osname">NetBSD</systemitem>
      <indexterm><primary>NetBSD</primary><secondary>IPC configuration</secondary></indexterm>
      </term>
      <listitem>
       <para>
        The default shared memory settings are usually good enough, unless
        you have set <literal>shared_memory_type</literal> to <literal>sysv</literal>.
        However, you will need to increase <literal>kern.ipc.semmni</literal>
        and <literal>kern.ipc.semmns</literal>,
        as <systemitem class="osname">NetBSD</systemitem>'s default settings
        for these are unworkably small.
       </para>

       <para>
        IPC parameters can be adjusted using <command>sysctl</command>,
        for example:
<screen>
<prompt>#</prompt> <userinput>sysctl -w kern.ipc.semmni=100</userinput>
</screen>
        To make these settings persist over reboots, modify
        <filename>/etc/sysctl.conf</filename>.
       </para>

       <para>
        If you have set <literal>shared_memory_type</literal> to
        <literal>sysv</literal>, you might also want to configure your kernel
        to lock System V shared memory into RAM and prevent it from being paged
        out to swap.  This can be accomplished using the <command>sysctl</command>
        setting <literal>kern.ipc.shm_use_phys</literal>.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><systemitem class="osname">OpenBSD</systemitem>
      <indexterm><primary>OpenBSD</primary><secondary>IPC configuration</secondary></indexterm>
      </term>
      <listitem>
       <para>
        The default shared memory settings are usually good enough, unless
        you have set <literal>shared_memory_type</literal> to <literal>sysv</literal>.
        However, you will need to
        increase <literal>kern.seminfo.semmni</literal>
        and <literal>kern.seminfo.semmns</literal>,
        as <systemitem class="osname">OpenBSD</systemitem>'s default settings
        for these are unworkably small.
       </para>

       <para>
        IPC parameters can be adjusted using <command>sysctl</command>,
        for example:
<screen>
<prompt>#</prompt> <userinput>sysctl kern.seminfo.semmni=100</userinput>
</screen>
        To make these settings persist over reboots, modify
        <filename>/etc/sysctl.conf</filename>.
       </para>

      </listitem>
     </varlistentry>

     <varlistentry>
      <term><systemitem class="osname">Linux</systemitem>
      <indexterm><primary>Linux</primary><secondary>IPC configuration</secondary></indexterm>