[PATCH] kernel.h: Add a never optimized away pr_dbg for printk(KERN_DEBUG pr_fmt(fmt)...)

[Joe Perches <joe@perches.com>]

Many developers use a logging message that
is printed at KERN_DEBUG level that is always
printed regardless of #define DEBUG levels.

pr_debug can be optimized away to a null statement.

Add a pr_dbg message that prints at KERN_DEBUG
level that uses pr_fmt() that can not be optimized
to nothing.

Signed-off-by: Joe Perches <joe@perches.com>

 include/linux/kernel.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index f4e3184..2ad0396 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -380,6 +380,8 @@ static inline char *pack_hex_byte(char *buf, u8
byte)
         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 #define pr_info(fmt, ...) \
         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_dbg(fmt, ...) \
+        printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 #define pr_cont(fmt, ...) \
 	printk(KERN_CONT fmt, ##__VA_ARGS__)