Re: [PATCH v2 1/5] printk/nmi: Generic solution for safe printk in NMI

From: Jiri Kosina <jikos@kernel.org>
To: Petr Mladek <pmladek@suse.com>
Cc: kbuild test robot <lkp@intel.com>,
	kbuild-all@01.org, Andrew Morton <akpm@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Russell King <rmk+kernel@arm.linux.org.uk>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-arm-kernel@lists.infradead.org,
	adi-buildroot-devel@lists.sourceforge.net,
	linux-cris-kernel@axis.com, linux-mips@linux-mips.org,
	linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
	linux-sh@vger.kernel.org, sparclinux@vger.kernel.org,
	David Howells <dhowells@redhat.com>,
	Koichi Yasutake <yasutake.koichi@jp.panasonic.com>,
	linux-am33-list@redhat.com
Subject: Re: [PATCH v2 1/5] printk/nmi: Generic solution for safe printk in NMI
Date: Wed, 2 Dec 2015 00:24:49 +0100 (CET)	[thread overview]
Message-ID: <alpine.LNX.2.00.1512020022460.32500@pobox.suse.cz> (raw)
In-Reply-To: <20151127153804.GC2648@pathway.suse.cz>

On Fri, 27 Nov 2015, Petr Mladek wrote:

> MN10300 has its own implementation for entering and exiting NMI 
> handlers. It does not call nmi_enter() and nmi_exit(). Please, find 
> below an updated patch that adds printk_nmi_enter() and 
> printk_nmi_exit() to the custom entry points. Then we could add HAVE_NMI 
> to arch/mn10300/Kconfig and avoid the above warning.

Hmm, so what exactly would go wrong if MN10300 (whatever that architecture 
is) would call nmi_enter() and nmi_exit() at the places where it's 
starting and finishing NMI handler?

>From a cursory look, it seems like most (if not all) of the things called 
from nmi_{enter,exit}() would be nops there anyway.

Thanks,

-- 
Jiri Kosina
SUSE Labs