diff options
| -rw-r--r-- | doc/src/sgml/runtime.sgml | 62 |
1 files changed, 43 insertions, 19 deletions
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 8d9d40664b4..333adda4086 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -796,7 +796,8 @@ psql: could not connect to server: No such file or directory <para> In some cases it might also be necessary to increase <varname>SEMMAP</varname> to be at least on the order of - <varname>SEMMNS</varname>. This parameter defines the size of the semaphore + <varname>SEMMNS</varname>. If the system has this parameter + (many do not), it defines the size of the semaphore resource map, in which each contiguous block of available semaphores needs an entry. When a semaphore set is freed it is either added to an existing entry that is adjacent to the freed block or it is @@ -853,7 +854,7 @@ psql: could not connect to server: No such file or directory </term> <listitem> <para> - The default settings can be changed using + 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>: @@ -872,13 +873,9 @@ psql: could not connect to server: No such file or directory <programlisting> kern.ipc.semmni=256 kern.ipc.semmns=512 -kern.ipc.semmnu=256 </programlisting> - After modifying these values a reboot is required for the new + After modifying that file, a reboot is required for the new settings to take effect. - (Note: FreeBSD does not use <varname>SEMMAP</varname>. Older versions - would accept but ignore a setting for <literal>kern.ipc.semmap</literal>; - newer versions reject it altogether.) </para> <para> @@ -902,7 +899,7 @@ kern.ipc.semmnu=256 <para> <systemitem class="osname">FreeBSD</systemitem> versions before 4.0 work like - <systemitem class="osname">OpenBSD</systemitem> (see below). + old <systemitem class="osname">OpenBSD</systemitem> (see below). </para> </listitem> </varlistentry> @@ -917,13 +914,20 @@ kern.ipc.semmnu=256 IPC parameters can be adjusted using <command>sysctl</command>, for example: <screen> -<prompt>$</prompt> <userinput>sysctl -w kern.ipc.shmmax=16777216</userinput> +<prompt>#</prompt> <userinput>sysctl -w kern.ipc.semmni=100</userinput> </screen> - To have these settings persist over reboots, modify + To make these settings persist over reboots, modify <filename>/etc/sysctl.conf</filename>. </para> <para> + You will usually want 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 uncomfortably small. + </para> + + <para> You might also want to configure your kernel to lock shared memory into RAM and prevent it from being paged out to swap. This can be accomplished using the <command>sysctl</command> @@ -931,10 +935,10 @@ kern.ipc.semmnu=256 </para> <para> - <systemitem class="osname">NetBSD</systemitem> versions before 5.0 work like - <systemitem class="osname">OpenBSD</systemitem> (see below), except that - parameters should be set with the keyword <literal>options</literal> not - <literal>option</literal>. + <systemitem class="osname">NetBSD</systemitem> versions before 5.0 + work like old <systemitem class="osname">OpenBSD</systemitem> + (see below), except that kernel parameters should be set with the + keyword <literal>options</literal> not <literal>option</literal>. </para> </listitem> </varlistentry> @@ -945,11 +949,31 @@ kern.ipc.semmnu=256 </term> <listitem> <para> - The options <varname>SYSVSHM</varname> and <varname>SYSVSEM</varname> need - to be enabled when the kernel is compiled. (They are by - default.) The maximum size of shared memory is determined by - the option <varname>SHMMAXPGS</varname> (in pages). The following - shows an example of how to set the various parameters: + In <systemitem class="osname">OpenBSD</systemitem> 3.3 and later, + 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> + + <para> + You will usually want 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 uncomfortably small. + </para> + + <para> + In older <systemitem class="osname">OpenBSD</systemitem> versions, + you will need to build a custom kernel to change the IPC parameters. + Make sure that the options <varname>SYSVSHM</varname> + and <varname>SYSVSEM</varname> are enabled, too. (They are by + default.) The following shows an example of how to set the various + parameters in the kernel configuration file: <programlisting> option SYSVSHM option SHMMAXPGS=4096 |