[PATCH V2] printk/cache: Mark printk_once test variable__read_mostly

From: Joe Perches
Date: Wed Oct 30 2013 - 19:01:53 EST


Add #include <linux/cache.h> to define __read_mostly.

Convert cache.h to use uapi/linux/kernel.h instead
of linux/kernel.h to avoid recursive #includes.

Convert the ALIGN macro to __KERNEL_ALIGN.

printk_once only sets the bool variable tested
once so mark it __read_mostly.

Neaten the alignment so it matches the rest of the
pr_<level>_once #defines too.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
V2: Add cache.h which was nearly always used
indirectly via #include <some_other_file.h>,
generally module.h
Update cache.h to avoid recursive #include

include/linux/cache.h | 4 ++--
include/linux/printk.h | 19 ++++++++++---------
2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/include/linux/cache.h b/include/linux/cache.h
index 4c57065..63a1d97 100644
--- a/include/linux/cache.h
+++ b/include/linux/cache.h
@@ -1,11 +1,11 @@
#ifndef __LINUX_CACHE_H
#define __LINUX_CACHE_H

-#include <linux/kernel.h>
+#include <uapi/linux/kernel.h>
#include <asm/cache.h>

#ifndef L1_CACHE_ALIGN
-#define L1_CACHE_ALIGN(x) ALIGN(x, L1_CACHE_BYTES)
+#define L1_CACHE_ALIGN(x) __KERNEL_ALIGN(x, L1_CACHE_BYTES)
#endif

#ifndef SMP_CACHE_BYTES
diff --git a/include/linux/printk.h b/include/linux/printk.h
index e6131a78..2449da9 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -5,6 +5,7 @@
#include <linux/init.h>
#include <linux/kern_levels.h>
#include <linux/linkage.h>
+#include <linux/cache.h>

extern const char linux_banner[];
extern const char linux_proc_banner[];
@@ -251,17 +252,17 @@ extern asmlinkage void dump_stack(void) __cold;
*/

#ifdef CONFIG_PRINTK
-#define printk_once(fmt, ...) \
-({ \
- static bool __print_once; \
- \
- if (!__print_once) { \
- __print_once = true; \
- printk(fmt, ##__VA_ARGS__); \
- } \
+#define printk_once(fmt, ...) \
+({ \
+ static bool __print_once __read_mostly; \
+ \
+ if (!__print_once) { \
+ __print_once = true; \
+ printk(fmt, ##__VA_ARGS__); \
+ } \
})
#else
-#define printk_once(fmt, ...) \
+#define printk_once(fmt, ...) \
no_printk(fmt, ##__VA_ARGS__)
#endif



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/