printk: convert the format for KERN_<LEVEL> to a 2 byte pattern
Instead of "<.>", use an ASCII SOH for the KERN_<LEVEL> prefix initiator.
This saves 1 byte per printk, thousands of bytes in a normal kernel.
No output changes are produced as vprintk_emit converts these uses to
"<.>".
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kern_levels.h b/include/linux/kern_levels.h
index 337e56f..8c719a9 100644
--- a/include/linux/kern_levels.h
+++ b/include/linux/kern_levels.h
@@ -1,22 +1,25 @@
#ifndef __KERN_LEVELS_H__
#define __KERN_LEVELS_H__
-#define KERN_EMERG "<0>" /* system is unusable */
-#define KERN_ALERT "<1>" /* action must be taken immediately */
-#define KERN_CRIT "<2>" /* critical conditions */
-#define KERN_ERR "<3>" /* error conditions */
-#define KERN_WARNING "<4>" /* warning conditions */
-#define KERN_NOTICE "<5>" /* normal but significant condition */
-#define KERN_INFO "<6>" /* informational */
-#define KERN_DEBUG "<7>" /* debug-level messages */
+#define KERN_SOH "\001" /* ASCII Start Of Header */
+#define KERN_SOH_ASCII '\001'
-/* Use the default kernel loglevel */
-#define KERN_DEFAULT "<d>"
+#define KERN_EMERG KERN_SOH "0" /* system is unusable */
+#define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
+#define KERN_CRIT KERN_SOH "2" /* critical conditions */
+#define KERN_ERR KERN_SOH "3" /* error conditions */
+#define KERN_WARNING KERN_SOH "4" /* warning conditions */
+#define KERN_NOTICE KERN_SOH "5" /* normal but significant condition */
+#define KERN_INFO KERN_SOH "6" /* informational */
+#define KERN_DEBUG KERN_SOH "7" /* debug-level messages */
+
+#define KERN_DEFAULT KERN_SOH "d" /* the default kernel loglevel */
+
/*
* Annotation for a "continued" line of log printout (only done after a
* line that had no enclosing \n). Only to be used by core/arch code
* during early bootup (a continued line is not SMP-safe otherwise).
*/
-#define KERN_CONT "<c>"
+#define KERN_CONT KERN_SOH "c"
#endif