[PATCH] move LOG_BUF_SIZE to header/config

Patch from "Randy.Dunlap" <rddunlap@osdl.org>

Convert the selection of LOG_BUF_SIZE from an ifdef tangle in
printk.c into config logic.

init/Kconfig

@@ -82,6 +82,51 @@ 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
+
 endmenu
 
 

kernel/printk.c

@@ -31,16 +31,7 @@
 
 #include <asm/uaccess.h>
 
-#if defined(CONFIG_X86_NUMAQ) || defined(CONFIG_IA64)
-#define LOG_BUF_LEN	(65536)
-#elif defined(CONFIG_ARCH_S390)
-#define LOG_BUF_LEN	(131072)
-#elif defined(CONFIG_SMP)
-#define LOG_BUF_LEN	(32768)
-#else	
-#define LOG_BUF_LEN	(16384)			/* This must be a power of two */
-#endif
-
+#define LOG_BUF_LEN	(1 << CONFIG_LOG_BUF_SHIFT)
 #define LOG_BUF_MASK	(LOG_BUF_LEN-1)
 
 /* printk's without a loglevel use this.. */