[PATCH] update LOG BUF SIZE config.

The current LOG_BUF size is a bit confusing the first
time that "make oldconfig" is used.  It's difficult to
select anything other than the default value.

Also, you (Linus) expressed a desire to have this
configurable only if DEBUG_KERNEL or "kernel hacking"
was enabled, so I've changed it to accomplish that.

This patch also uses Kconfig in a way that Roman intended
since a patch in 2.5.52 which enables default values if
a prompt is not enabled, but lets values be chosen when
the prompt is enabled.  You also asked for this in setting
this config option.

init/Kconfig

@@ -82,50 +82,21 @@ config SYSCTL
 	  building a kernel for install/rescue disks or your system is very
 	  limited in memory.
 
-choice
-	prompt "Kernel log buffer size"
-	default LOG_BUF_SHIFT_17 if ARCH_S390
-	default LOG_BUF_SHIFT_16 if X86_NUMAQ || IA64
-	default LOG_BUF_SHIFT_15 if SMP
-	default LOG_BUF_SHIFT_14
-	help
-	  Select kernel log buffer size from this list (power of 2).
-	  Defaults:  17 (=> 128 KB for S/390)
-		     16 (=> 64 KB for x86 NUMAQ or IA-64)
-	             15 (=> 32 KB for SMP)
-	             14 (=> 16 KB for uniprocessor)
-
-config LOG_BUF_SHIFT_17
-	bool "128 KB"
-	default y if ARCH_S390
-
-config LOG_BUF_SHIFT_16
-	bool "64 KB"
-	default y if X86_NUMAQ || IA64
-
-config LOG_BUF_SHIFT_15
-	bool "32 KB"
-	default y if SMP
-
-config LOG_BUF_SHIFT_14
-	bool "16 KB"
-
-config LOG_BUF_SHIFT_13
-	bool "8 KB"
-
-config LOG_BUF_SHIFT_12
-	bool "4 KB"
-
-endchoice
-
 config LOG_BUF_SHIFT
-	int
-	default 17 if LOG_BUF_SHIFT_17=y
-	default 16 if LOG_BUF_SHIFT_16=y
-	default 15 if LOG_BUF_SHIFT_15=y
-	default 14 if LOG_BUF_SHIFT_14=y
-	default 13 if LOG_BUF_SHIFT_13=y
-	default 12 if LOG_BUF_SHIFT_12=y
+	int "Kernel log buffer size" if DEBUG_KERNEL
+	default 17 if ARCH_S390
+	default 16 if X86_NUMAQ || IA64
+	default 15 if SMP
+	default 14
+	help
+	  Select kernel log buffer size as a power of 2.
+	  Defaults and Examples:
+	  	     17 => 128 KB for S/390
+		     16 => 64 KB for x86 NUMAQ or IA-64
+	             15 => 32 KB for SMP
+	             14 => 16 KB for uniprocessor
+		     13 =>  8 KB
+		     12 =>  4 KB
 
 endmenu