diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-02-05 12:45:43 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-02-05 12:52:29 (GMT) |
commit | f036be96dd9ce442ffb9ab33e3c165f5178815c0 (patch) | |
tree | c60c39f895bb93ac0000de7772e89a0b6663954b /include | |
parent | eda58a85ec3fc05855a26654d97a2b53f0e715b9 (diff) | |
download | linux-fsl-qoriq-f036be96dd9ce442ffb9ab33e3c165f5178815c0.tar.xz |
printk: introduce printk_once()
This pattern shows up frequently in the kernel:
static int once = 1;
...
if (once) {
once = 0;
printk(KERN_ERR "message\n");
}
...
So add a printk_once() helper macro that reduces this to a single line
of:
printk_once(KERN_ERR "message\n");
It works analogously to WARN_ONCE() & friends. (We use a macro not
an inline because vararg expansion in inlines looks awkward and the
macro is simple enough.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/kernel.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 343df9e..3c183d9 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -242,6 +242,19 @@ extern struct ratelimit_state printk_ratelimit_state; extern int printk_ratelimit(void); extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msec); + +/* + * Print a one-time message (analogous to WARN_ONCE() et al): + */ +#define printk_once(x...) ({ \ + static int __print_once = 1; \ + \ + if (__print_once) { \ + __print_once = 0; \ + printk(x); \ + } \ +}) + #else static inline int vprintk(const char *s, va_list args) __attribute__ ((format (printf, 1, 0))); @@ -253,6 +266,10 @@ static inline int printk_ratelimit(void) { return 0; } static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \ unsigned int interval_msec) \ { return false; } + +/* No effect, but we still get type checking even in the !PRINTK case: */ +#define printk_once(x...) printk(x) + #endif extern int printk_needs_cpu(int cpu); |