Re: [V5][PATCH 3/6] x86, nmi: wire up NMI handlers to new routines

[Don Zickus <dzickus@redhat.com>]

On Wed, Sep 21, 2011 at 12:49:36PM +0200, Borislav Petkov wrote:
> + Tony.
> 
> On Wed, Sep 21, 2011 at 01:41:39PM +0800, Huang Ying wrote:
> > On 09/20/2011 10:43 PM, Don Zickus wrote:
> > > Just convert all the files that have an nmi handler to the new routines.
> > > Most of it is straight forward conversion.  A couple of places needed some
> > > tweaking like kgdb which separates the debug notifier from the nmi handler
> > > and mce removes a call to notify_die (as I couldn't figure out why it was
> > > there).
> > 
> > It is used to call a debugger on a machine check, according to following
> > thread:
> > 
> > https://lkml.org/lkml/2010/5/27/114
> 
> Thanks for digging that out - I couldn't find anywhere in the git logs
> why was this added in the first place.
> 
> > So maybe we can turn that into a kgdb direct call?
> 
> After reading the thread, the semi-legitimate usage of using it as
> a jump into the debugger just because some hardware reports certain
> conditions through an MCE sounds pretty hacky to me.
> 
> Besides, if the driver developer needs that, he can add the code for the
> duration of her/his development cycle as aid, and remove it in the end.
> 
> This early-exit deal is especially inacceptable if you get an
> uncorrectable error and some notifier call in the chain consumes it and
> we never get to report it or decode it, or do recovery action. And thus
> the box merrily continues on although a corruption just happened and we
> didn't even get a chance to panic.
> 
> So I really really want to remove it, actually.

Cool.  Thanks Ying and Boris for settling that.  I was scratching my head
trying to understand why that was there.  It keeps the code simpler to
now. :-)

Cheers,
Don