Re: [PATCH 3/3] lib/vsprintf: Use pr_crit() instead of long fancy messages

From: Petr Mladek via iommu <iommu@lists.linux-foundation.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marco Elver <elver@google.com>,
	Linux Embedded <linux-embedded@vger.kernel.org>,
	John Ogness <john.ogness@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Linux IOMMU <iommu@lists.linux-foundation.org>,
	Ingo Molnar <mingo@redhat.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Will Deacon <will@kernel.org>, Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH 3/3] lib/vsprintf: Use pr_crit() instead of long fancy messages
Date: Thu, 20 May 2021 14:51:50 +0200	[thread overview]
Message-ID: <YKZbZhACyIENhM8S@alley> (raw)
In-Reply-To: <CAMuHMdXQArCn9BS_8p0iUAgomfEHWe8ypg=B_SGfvJu8c_L5vg@mail.gmail.com>

On Mon 2021-05-17 08:21:12, Geert Uytterhoeven wrote:
> On Wed, Mar 31, 2021 at 11:59 AM Geert Uytterhoeven
> <geert+renesas@glider.be> wrote:
> > While long fancy messages have a higher probability of being seen than
> > small messages, they may scroll of the screen fast, if visible at all,
> > and may still be missed.  In addition, they increase boot time and
> > kernel size.
> >
> > The correct mechanism to increase importance of a kernel message is not
> > to draw fancy boxes with more text, but to shout louder, i.e. increase
> > the message's reporting level.  Making sure the administrator of the
> > system is aware of such a message is a system policy, and is the
> > responsability of a user-space log daemon.
> >
> > Fix this by increasing the reporting level from KERN_WARNING to
> > KERN_CRIT, and removing irrelevant text and graphics.
> >
> > This reduces kernel size by ca. 0.5 KiB.
> >
> > Fixes: 5ead723a20e0447b ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed")
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> No comments?
> Unlike the cases handled by the other two patches in this series,
> this one cannot be configured out.

IMHO, the best solution would be to create a generic API for
eye-catching messages.

I am sure that WARN() is misused on many locations all over the kernel
because people just wanted eye-catching message, for example, see
https://lore.kernel.org/r/2149df3f542d25ce15d049e81d6188bb7198478c.camel@fi.rohmeurope.com

It might be a win-win solution.

Best Regards,
Petr
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu