Adjust OS-specific kernel settings to mention old and new BSD methods of

adjusting values:

> 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.

Mark Kirkwood

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 94c03bb5496da6e19f851bac269bc862a05667d9..3ae948e258671b4554cb69405c44fa0e65b7a711 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,5 +1,5 @@
 
 
 
@@ -4458,37 +4458,29 @@ option         SEMMAP=256
       LinuxIPC configuration
       
        
-        The default shared memory limit (both
-        SHMMAX and SHMALL) is 32
-        MB in 2.2 kernels, but it can be changed in the
-        proc 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 
+        sysctl interface. For example, to allow 128 MB, 
+        and explicitly set the maximum total shared memory size to 2097152 
+        pages (the default):
 
-$ echo 134217728 >/proc/sys/kernel/shmall
-$ echo 134217728 >/proc/sys/kernel/shmmax
+$ systcl -w kernel.shmmax=134217728
+$ systcl -w kernel.shmall=2097152
 
-        You could put these commands into a script run at boot-time.
+        In addition these settings can be saved between reboots in 
+        /etc/sysctl.conf.
        
 
        
-        Alternatively, you can use sysctl, if
-        available, to control these parameters.  Look for a file
-        called /etc/sysctl.conf and add lines
-        like the following to it:
-
-kernel.shmall = 134217728
-kernel.shmmax = 134217728
-
-        This file is usually processed at boot time, but
-        sysctl can also be called
-        explicitly later.
-       
-
-       
-        Other parameters are sufficiently sized for any application. If
-        you want to see for yourself look in
-        /usr/src/linux/include/asm-xxx/shmparam.h
-        and /usr/src/linux/include/linux/sem.h.
+        Older distributions may not have the sysctl program,
+        but equivalent changes can be made by manipulating the 
+        /proc filesystem:
+
+$ echo 134217728 >/proc/sys/kernel/shmmax
+$ echo 2097152 >/proc/sys/kernel/shmall
+