Commit 70867453 authored Sep 22, 2009 by Roland Dreier Committed by Linus Torvalds Sep 23, 2009

printk_once(): use bool for boolean flag



Using the type bool (instead of int) for the __print_once flag in the
printk_once() macro matches the intent of the code better, and allows the
compiler to generate smaller code; eg a typical callsite with gcc 4.3.3 on
i386:

add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-6 (-6)
function                                     old     new   delta
static.__print_once                            4       1      -3
get_cpu_vendor                               146     143      -3

Saving 6 bytes of object size per callsite by slightly improving the
readability of the source seems like a win to me.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 02b51df1

include/linux/kernel.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -252,10 +252,10 @@ extern int printk_delay_msec;
		* Print a one-time message (analogous to WARN_ONCE() et al):
		*/
		#define printk_once(x...) ({ \
		static int __print_once = 1; \
		static bool __print_once = true; \
		\
		if (__print_once) { \
		__print_once = 0; \
		__print_once = false; \
		printk(x); \
		} \
		})

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