Re: [PATCH 1/3] Add ratelimited printk for different alert levels

[Joe Perches <joe@xxxxxxxxxxx>]

On Wed, 2012-09-12 at 03:43 +0530, raghu.prabhu13@xxxxxxxxx wrote:
> Ratelimited printk will be useful in printing xfs messages which are otherwise
> not required to be printed always due to their high rate (to prevent kernel 
> ring
> buffer from overflowing), while at the same time required to be printed.
[]
> diff --git a/fs/xfs/xfs_message.h b/fs/xfs/xfs_message.h
[]
> @@ -30,6 +32,32 @@ void xfs_debug(const struct xfs_mount *mp, const char 
> *fmt, ...)
>  }
>  #endif
>  
> +#define xfs_printk_ratelimited(xfs_printk, dev, fmt, ...)            \
> +do {                                                                 \
> +     static DEFINE_RATELIMIT_STATE(_rs,                              \
> +                                   DEFAULT_RATELIMIT_INTERVAL,       \
> +                                   DEFAULT_RATELIMIT_BURST);         \
> +     if (__ratelimit(&_rs))                                          \
> +             xfs_printk(dev, fmt, ##__VA_ARGS__);                    \
> +} while (0)

It might be better to use an xfs singleton RATELIMIT_STATE

DEFINE_RATELIMIT_STATE(xfs_rs);
...
#define xfs_printk_ratelimited(xfs_printk, dev, fmt, ...)               \
do {                                                                    \
        if (__ratelimit(&xfs_rs))                                       \
                xfs_printk(dev, fmt, ##__VA_ARGS__);                    \
} while (0)