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

From: Petr Mladek
Date: Fri Dec 04 2015 - 11:57:55 EST


On Wed 2015-12-02 00:24:49, Jiri Kosina wrote:
> 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.

Good point. Max mentioned in the other main that the NMI handler
should follow the NMI ruler. I do not why it could not work.
In fact, it might improve things, e.g. nmi_enter() blocks
recursive NMIs.

I think that it will move it into a separate patch, thought.

Best Regards,
Petr
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