Re: [23/27] kernel.h: add printk_ratelimited and pr__rl

Phil Carmody
2012-01-24T14:49:12Z

On 23/01/12 15:41 -0800, ext Greg KH wrote:
> 2.6.32-longterm review patch. If anyone has any objections, please let me know.

This looks like an added feature with no users in .32 - does it really
belong in a stable tree?
(But to be explicit, I have no issue with its contents at all.)

Phil

> ------------------
>
>
> From: Joe Perches <joe@perches.com>
>
> commit 8a64f336bc1d4aa203b138d29d5a9c414a9fbb47 upstream.
>
> Add a printk_ratelimited statement expression macro that uses a per-call
> ratelimit_state so that multiple subsystems output messages are not
> suppressed by a global __ratelimit state.
>
> [akpm@linux-foundation.org: coding-style fixes]
> [akpm@linux-foundation.org: s/_rl/_ratelimited/g]
> Signed-off-by: Joe Perches <joe@perches.com>
> Cc: Naohiro Ooiwa <nooiwa@miraclelinux.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
>
> ---
> include/linux/kernel.h | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -407,6 +407,50 @@ static inline char *pack_hex_byte(char *
> #endif
>
> /*
> + * ratelimited messages with local ratelimit_state,
> + * no local ratelimit_state used in the !PRINTK case
> + */
> +#ifdef CONFIG_PRINTK
> +#define printk_ratelimited(fmt, ...) ({ \
> + static struct ratelimit_state _rs = { \
> + .interval = DEFAULT_RATELIMIT_INTERVAL, \
> + .burst = DEFAULT_RATELIMIT_BURST, \
> + }; \
> + \
> + if (!__ratelimit(&_rs)) \
> + printk(fmt, ##__VA_ARGS__); \
> +})
> +#else
> +/* No effect, but we still get type checking even in the !PRINTK case: */
> +#define printk_ratelimited printk
> +#endif
> +
> +#define pr_emerg_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_alert_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_crit_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_err_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_warning_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_notice_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_info_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
> +/* no pr_cont_ratelimited, don't do that... */
> +/* If you are writing a driver, please use dev_dbg instead */
> +#if defined(DEBUG)
> +#define pr_debug_ratelimited(fmt, ...) \
> + printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
> +#else
> +#define pr_debug_ratelimited(fmt, ...) \
> + ({ if (0) printk_ratelimited(KERN_DEBUG pr_fmt(fmt), \
> + ##__VA_ARGS__); 0; })
> +#endif
> +
> +/*
> * General tracing related utility functions - trace_printk(),
> * tracing_on/tracing_off and tracing_start()/tracing_stop
> *
>
>
> --
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