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>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/printk.h b/include/linux/printk.h
index fea2de37b645..93a231f9835c 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -9,7 +9,7 @@ extern const char linux_proc_banner[];
 
 static inline int printk_get_level(const char *buffer)
 {
-        if (buffer[0] == '<' && buffer[1] && buffer[2] == '>') {
+        if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
                 switch (buffer[1]) {
                 case '0' ... '7':
                 case 'd':       /* KERN_DEFAULT */
@@ -27,7 +27,7 @@ static inline const char *printk_skip_level(const char *buffer)
                 case '0' ... '7':
                 case 'd':       /* KERN_DEFAULT */
                 case 'c':       /* KERN_CONT */
-                        return buffer + 3;
+                        return buffer + 2;
                 }
         }
         return buffer;