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From:   Lucas De Marchi <lucas.de.marchi@gmail.com>
Date:   Mon, 20 Sep 2021 22:53:53 -0700
Message-ID: <CAKi4VAKa7LKXdRmA7epgbkUZw2wpUz19JYYdZ35mPCxSL_W_kw@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] libkmod: add a library notice log level print
To:     Luis Chamberlain <mcgrof@kernel.org>
Cc:     Lucas De Marchi <lucas.demarchi@intel.com>,
        linux-modules <linux-modules@vger.kernel.org>,
        live-patching@vger.kernel.org, fstests@vger.kernel.org,
        linux-block@vger.kernel.org, hare@suse.de, dgilbert@interlog.com,
        Jessica Yu <jeyu@kernel.org>, osandov@fb.com,
        lkml <linux-kernel@vger.kernel.org>
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On Mon, Aug 9, 2021 at 11:56 PM Luis Chamberlain <mcgrof@kernel.org> wrote:
>
> When you use pass the -v argument to modprobe we bump
> the log level from the default modprobe log level of
> LOG_WARNING (4) to LOG_NOTICE (5), however the library
> only has avaiable to print:
>
>  #define DBG(ctx, arg...) kmod_log_cond(ctx, LOG_DEBUG, ## arg)
>  #define INFO(ctx, arg...) kmod_log_cond(ctx, LOG_INFO, ## arg)
>  #define ERR(ctx, arg...) kmod_log_cond(ctx, LOG_ERR, ## arg)
>
> LOG_INFO (6) however is too high of a level for it to be
> effective at printing anything when modprobe -v is passed.
> And so the only way in which modprobe -v can trigger the
> library to print a verbose message is to use ERR() but that
> always prints something and we don't want that in some
> situations.
>
> We need to add a new log level macro which uses LOG_NOTICE (5)
> for a "normal but significant condition" which users and developers
> can use to look underneath the hood to confirm if a situation is
> happening.
>
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> ---
>  libkmod/libkmod-internal.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
> index 398af9c..2e5e1bc 100644
> --- a/libkmod/libkmod-internal.h
> +++ b/libkmod/libkmod-internal.h
> @@ -25,10 +25,12 @@ static _always_inline_ _printf_format_(2, 3) void
>  #  else
>  #    define DBG(ctx, arg...) kmod_log_null(ctx, ## arg)
>  #  endif
> +#  define NOTICE(ctx, arg...) kmod_log_cond(ctx, LOG_NOTICE, ## arg)
>  #  define INFO(ctx, arg...) kmod_log_cond(ctx, LOG_INFO, ## arg)
>  #  define ERR(ctx, arg...) kmod_log_cond(ctx, LOG_ERR, ## arg)
>  #else
>  #  define DBG(ctx, arg...) kmod_log_null(ctx, ## arg)
> +#  define NOTICE(ctx, arg...) kmod_log_cond(ctx, LOG_NOTICE, ## arg)

did you mean kmod_log_null()?

Lucas De Marchi

>  #  define INFO(ctx, arg...) kmod_log_null(ctx, ## arg)
>  #  define ERR(ctx, arg...) kmod_log_null(ctx, ## arg)
>  #endif
> --
> 2.30.2
>