Re: Instructions for Linux ipc config

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Mark Kirkwood wrote:
> Attached are my first thoughts for the amended instructions.
>
> Mark Kirkwood wrote:
> >
> > But to be on the safe side, it would make sense to do something similar
> > to the BSD section, and comment about older distributions maybe needing
> > to manipulate /proc/kernel/* directly.
> >
>
>

> --- runtime.sgml.orig Fri Feb 4 22:17:45 2005
> +++ runtime.sgml Fri Feb 4 22:17:57 2005
> @@ -4414,37 +4414,29 @@
> <indexterm><primary>Linux</><secondary>IPC configuration</></>
> <listitem>
> <para>
> - The default shared memory limit (both
> - <varname>SHMMAX</varname> and <varname>SHMALL</varname>) is 32
> - MB in 2.2 kernels, but it can be changed in the
> - <filename>proc</filename> file system (without reboot). For
> - example, to allow 128 MB:
> + The default settings are only suitable for small installations
> + (the default max segment size is 32 MB). However the remaining
> + defaults are quite generously sized, and usually do not require
> + changes. The max segment size can be changed via the
> + <command>sysctl</command> interface. For example, to allow 128 MB,
> + and explicitly set the maximum total shared memory size to 2097152
> + pages (the default):
> <screen>
> -<prompt>$</prompt> <userinput>echo 134217728 &gt;/proc/sys/kernel/shmall</userinput>
> -<prompt>$</prompt> <userinput>echo 134217728 &gt;/proc/sys/kernel/shmmax</userinput>
> +<prompt>$</prompt> <userinput>systcl -w kernel.shmmax=134217728</userinput>
> +<prompt>$</prompt> <userinput>systcl -w kernel.shmall=2097152</userinput>
> </screen>
> - You could put these commands into a script run at boot-time.
> - </para>
> -
> - <para>
> - Alternatively, you can use <command>sysctl</command>, if
> - available, to control these parameters. Look for a file
> - called <filename>/etc/sysctl.conf</filename> and add lines
> - like the following to it:
> -<programlisting>
> -kernel.shmall = 134217728
> -kernel.shmmax = 134217728
> -</programlisting>
> - This file is usually processed at boot time, but
> - <command>sysctl</command> can also be called
> - explicitly later.
> + In addition these settings can be saved between reboots in
> + <filename>/etc/sysctl.conf.
> </para>
>
> <para>
> - Other parameters are sufficiently sized for any application. If
> - you want to see for yourself look in
> - <filename>/usr/src/linux/include/asm-<replaceable>xxx</>/shmparam.h</>
> - and <filename>/usr/src/linux/include/linux/sem.h</>.
> + Older distributions may not have the <command>sysctl</command> program,
> + but equivalent changes can be made by manipulating the
> + <filename>/proc</filename> filesystem:
> +<screen>
> +<prompt>$</prompt> <userinput>echo 134217728 &gt;/proc/sys/kernel/shmmax</userinput>
> +<prompt>$</prompt> <userinput>echo 2097152 &gt;/proc/sys/kernel/shmall</userinput>
> +</screen>
> </para>
> </listitem>
> </varlistentry>
>

>
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