printk: convert the format for KERN_<LEVEL> to a 2 byte pattern
authorJoe Perches <joe@perches.com>
Mon, 30 Jul 2012 21:40:17 +0000 (14:40 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Jul 2012 00:25:14 +0000 (17:25 -0700)
commit04d2c8c83d0e3ac5f78aeede51babb3236200112
treec32b6197f9487cc18f00e85bdfb935a7a6a92477
parentb778b3f25baf46dd88f16d51f1682828be0aa2ad
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>
include/linux/kern_levels.h
include/linux/printk.h