Re: [PATCH v2 net-next 2/2] net: sock: undefine SOCK_DEBUGGING

[Joe Perches <joe@perches.com>]

On Sun, 2019-02-17 at 00:28 +0800, Yafang Shao wrote:
> SOCK_DEBUG() is a old facility for debugging.
> If the user want to use it for debugging, the user must modify the
> application first, that doesn't seem like a good way.
> Now we have more powerful facilities, i.e. bpf or tracepoint, for this kind
> of debugging purpose.
> So we'd better disable it by default.
> The reason why I don't remove it comepletely is that someone may still
> would like to use it for debugging.
> 
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> Suggested-by: Joe Perches <joe@perches.com>
> ---
>  include/net/sock.h | 13 ++++++++-----
>  net/core/sock.c    |  3 +++
>  2 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 6679f3c..d41e8f4 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -81,14 +81,17 @@
>   */
>  
>  /* Define this to get the SOCK_DBG debugging facility. */
> -#define SOCK_DEBUGGING
> +/* #define SOCK_DEBUGGING */
>  #ifdef SOCK_DEBUGGING
> -#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
> -					printk(KERN_DEBUG msg); } while (0)
> +#define SOCK_DEBUG(sk, fmt, ...)		\
> +do {						\
> +	if ((sk) && sock_flag((sk), SOCK_DBG))	\
> +		pr_debug(fmt, ##__VA_ARGS__);	\

trivia:

I would not suggest pr_debug here as it also requires
either DEBUG to be defined or CONFIG_DYNAMIC_DEBUG
to be set.

If you really set SOCK_DEBUGGING, then printk(KERN_DEBUG
is probably right.