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Added mention of SHMALL and removed BSD/OS-specific table.

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This commit is contained in:
Bruce Momjian 2001-05-02 17:04:53 +00:00
parent 4929d85e50
commit 8e393fc501
1 changed files with 25 additions and 35 deletions
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60
doc/src/sgml/runtime.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.59 2001/05/01 03:00:28 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.60 2001/05/02 17:04:53 momjian Exp $
-->
<Chapter Id="runtime">
@ -1449,7 +1449,7 @@ env PGOPTIONS='-c geqo=off' psql
<row>
<entry><varname>SHMMAX</></>
<entry>Maximum size of shared memory segment (bytes)</>
<entry>512 kB + 8192 * buffers + extra ... infinity</entry>
<entry>700 kB + 8192 * buffers + extra ... infinity</entry>
</row>
<row>
@ -1458,6 +1458,12 @@ env PGOPTIONS='-c geqo=off' psql
<entry>1 (at most about 256 kB)</>
</row>
<row>
<entry><varname>SHMALL</></>
<entry>Total amount of shared memory available (bytes or pages)</>
<entry>if bytes, same as SHMMAX; if pages, ceil(SHMMAX/PAGE_SIZE)</>
</row>
<row>
<entry><varname>SHMSEG</></>
<entry>Maximum number of shared memory segments per process</>
@ -1588,42 +1594,37 @@ env PGOPTIONS='-c geqo=off' psql
<para>
By default, only 4 MB of shared memory is supported. Keep in
mind that shared memory is not pageable; it is locked in RAM.
The shared memory parameters are:
To increase the number of shared buffers supported by the
postmaster, add the following to your kernel config file. A
<varname>SHMALL</> value of 1024 represents 4MB of shared
memory. The following increases the maximum shared memory area
to 32 MB:
<programlisting>
#define SHMMAX /* max shared memory segment size (bytes) */
#define SHMMIN /* min shared memory segment size (bytes) */
#define SHMMNI /* max number of shared memory identifiers */
#define SHMSEG /* max shared memory segments per process */
#define SHMALL /* max amount of shared memory (pages) */
</programlisting>
To increase the number of buffers supported by the postmaster, add the
following to your kernel config file. A <varname>SHMALL</> value of 1024
represents 4MB of shared memory. Increase it accordingly:
<programlisting>
options "SHMALL=4096"
options "SHMALL=8192"
options "SHMMAX=\(SHMALL*PAGE_SIZE\)"
</programlisting>
</para>
</formalpara>
<para>
For those running 4.1 or later, just recompile the kernel and
reboot. For those running earlier releases, use
<application>bpatch</> to find the <varname>sysptsize</> value
for the current kernel. This is computed dynamically at
bootup.
For those running 4.1 or later, just make the above changes,
recompile the kernel, and reboot. For those running earlier
releases, use <application>bpatch</> to find the
<varname>sysptsize</> value in the current kernel. This is
computed dynamically at bootup.
<screen>
$ <userinput>bpatch -r sysptsize</>
<computeroutput>0x9 = 9</>
</screen>
Next, change <varname>SYSPTSIZE</> to a hard-coded value. Use
the bpatch value, plus add 1 for every additional 4 MB of
Next, add <varname>SYSPTSIZE</> as a hard-coded value in the
kernel config file. Increase the value you found using
<application>bpatch</>. Add 1 for every additional 4 MB of
shared memory you desire.
<programlisting>
options "SYSPTSIZE=13"
options "SYSPTSIZE=16"
</programlisting>
<varname>sysptsize</> can not be changed by sysctl on the fly.
<varname>sysptsize</> can not be changed by sysctl.
</para>
<formalpara>
@ -1635,17 +1636,6 @@ options "SYSPTSIZE=13"
</para>
</formalpara>
<para>
The defaults are in <filename>/sys/sys/sem.h</>:
<programlisting>
#define SEMMNI 10 /* # of semaphore identifiers */
#define SEMMNS 60 /* # of semaphores in system */
#define SEMUME 10 /* max # of undo entries per process */
#define SEMMNU 30 /* # of undo structures in system */
</programlisting>
Set the values you want in your kernel config file, e.g.:
<programlisting>
options "SEMMNI=40"