linux-kernel - Re: [PATCH v3 2/4] lib/hexdump.c: factor out generic hexdump formatting for reuse.

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Date:   Wed, 27 Mar 2019 09:46:48 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Ronald Tschalär <ronald@...ovation.ch>
Cc:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Henrik Rydberg <rydberg@...math.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Lukas Wunner <lukas@...ner.de>,
        Federico Lorenzi <federico@...velground.com>,
        linux-input <linux-input@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/4] lib/hexdump.c: factor out generic hexdump
 formatting for reuse.

On Wed, Mar 27, 2019 at 3:49 AM Ronald Tschalär <ronald@...ovation.ch> wrote:
>
> This introduces print_hex_dump_to_cb() which contains all the hexdump
> formatting minus the actual printk() call, allowing an arbitrary print
> function to be supplied instead. And print_hex_dump() is re-implemented
> using print_hex_dump_to_cb().
>
> This allows other hex-dump logging functions to be provided which call
> printk() differently or even log the hexdump somewhere entirely
> different.

No Sign-off?

In any case, don't do it like this. smaller non-recursive printf() is
better than one big receursive call.
When it looks like an optimization, it's actually a regression.

And yes, debugfs idea is not bad.

P.S. Also check %*ph specifier.

-- 
With Best Regards,
Andy Shevchenko