Re: [PATCH v3 04/23] linux/net.h: use unique identifier for each struct _ddebug

[Joe Perches]

On Sat, 2018-11-10 at 00:10 +0100, Rasmus Villemoes wrote:
> Changes on x86-64 later in this series require that all struct _ddebug
> descriptors in a translation unit uses distinct identifiers. Realize
> that for net_dbg_ratelimited by generating such an identifier via
> __UNIQUE_ID and pass that to an extra level of macros.
> 
> No functional change.

Why does this require an extra indirection _<macro>?

> Cc: netdev@xxxxxxxxxxxxxxx
> Acked-by: Jason Baron <jbaron@xxxxxxxxxx>
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> ---
>  include/linux/net.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/net.h b/include/linux/net.h
> index 651fca72286c..397243a25f56 100644
> --- a/include/linux/net.h
> +++ b/include/linux/net.h
> @@ -260,7 +260,7 @@ do {								\
>  #define net_info_ratelimited(fmt, ...)				\
>  	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
>  #if defined(CONFIG_DYNAMIC_DEBUG)
> -#define net_dbg_ratelimited(fmt, ...)					\
> +#define _net_dbg_ratelimited(descriptor, fmt, ...)			\
>  do {									\
>  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
>  	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
> @@ -268,6 +268,8 @@ do {									\
>  		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
>  		                   ##__VA_ARGS__);			\
>  } while (0)
> +#define net_dbg_ratelimited(fmt, ...)					\
> +	_net_dbg_ratelimited(__UNIQUE_ID(ddebug), fmt, ##__VA_ARGS__)
>  #elif defined(DEBUG)
>  #define net_dbg_ratelimited(fmt, ...)				\
>  	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)