Improve OS X shared-memory documentation: fix typos and provide a usable

example of /etc/sysctl.conf contents.

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 8036944cab44e37bb65a99f4b1d6e36a1633739f..7dc5df33cb8f2796f0418c5c96300b7ac576faf5 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,5 +1,5 @@
 
 
 
@@ -878,27 +878,45 @@ sysctl -w kern.sysv.shmmni
 sysctl -w kern.sysv.shmseg
 sysctl -w kern.sysv.shmall
 
+       
+
+       
         In OS X 10.3 and later, these commands have been moved to
         /etc/rc and must be edited there.  Note that
         /etc/rc is usually overwritten by OS X updates (such as
         10.3.6 to 10.3.7) so you should expect to have to redo your editing
-        after each update.  In all versions, you'll need to reboot to make
-        changes take effect.  
+        after each update.
+       
+
+       
+        In OS X 10.3.9 and later, instead of editing /etc/rc
+        you may create a file named /etc/sysctl.conf,
+        containing variable assignments such as
+
+kern.sysv.shmmax=4194304
+kern.sysv.shmmin=1
+kern.sysv.shmmni=32
+kern.sysv.shmseg=8
+kern.sysv.shmall=1024
+
+        This method is better than editing /etc/rc because
+        your changes will be preserved across system updates.  Note that
+        all five shared-memory parameters must be set in
+        /etc/sysctl.conf, else the values will be ignored.
+       
+
+       
+        Beware that recent releases of OS X ignore attempts to set
+        SHMMAX to a value that isn't an exact multiple of 4096.
        
 
        
-        In OS X 10.3.9 and later, the file /etc/sysctl.conf
-        allows shared memory setting to be saved across operating system
-        upgrades, and is the recommended method for setting these
-        parameters. When using this file, all five shared memory values
-        must be set or the changes will be ignored.
+        SHMALL is measured in 4KB pages on this platform.
        
 
        
-        SHMALL is measured in 4KB pages on this platform,
-        and recent releases of OS X reject attempts to set 
-        and SHMMAX to a value that isn't an exact 
-        multiple of 4096.
+        In all OS X versions, you'll need to reboot to make changes in the
+        shared memory parameters take effect.