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Date:   Tue, 8 Aug 2023 15:49:54 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Petr Mladek <pmladek@suse.com>, Marco Elver <elver@google.com>,
        linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2 2/3] lib/vsprintf: Split out sprintf() and friends
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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On Mon, Aug 07, 2023 at 10:24:55PM -0400, Steven Rostedt wrote:
> On Mon, 7 Aug 2023 18:09:54 +0300
> Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> > On Mon, Aug 07, 2023 at 05:03:19PM +0200, Petr Mladek wrote:
> > > On Sat 2023-08-05 20:50:26, Andy Shevchenko wrote:  
> > > > kernel.h is being used as a dump for all kinds of stuff for a long time.
> > > > sprintf() and friends are used in many drivers without need of the full
> > > > kernel.h dependency train with it.
> > > > 
> > > > Here is the attempt on cleaning it up by splitting out sprintf() and
> > > > friends.  

...

> > > I agree that kernel.h is not the right place. But are there any
> > > numbers how much separate sprintf.h might safe?
> > > Maybe, we should not reinvent the wheel and get inspired by
> > > userspace.
> > > 
> > > sprintf() and friends are basic functions which most people know
> > > from userspace. And it is pretty handy that the kernel variants
> > > are are mostly compatible as well.
> > > 
> > > IMHO, it might be handful when they are also included similar way
> > > as in userspace. From my POV printk.h is like stdio.h. And we already
> > > have include/linux/stdarg.h where the v*print*() function might
> > > fit nicely.
> > > 
> > > How does this sound, please?  
> > 
> > Not every user (especially _header_) wants to have printk.h included just for
> > sprintf.h that may have nothing to do with real output. So, same reasoning
> > from me as keeping that in kernel.h, i.e. printk.h no better.
> 
> If you separate out the sprintf() into its own header and still include
> that in kernel.h, then for what you said in the other email:
> 
> > What to do with _headers_ that include kernel.h for no reason other than
> > sprintf.h (as an example)? Your suggestion, please?
> 
> It can include sprintf.h (or printk.h or stdio.h, whatever) instead of kernel.h.
> 
> What's the issue?

The issue is the same, printk.h brings a lot more than just s*printf().
Why should I include it for a, let's say, single sprintf() call?

-- 
With Best Regards,
Andy Shevchenko