Re: [PATCH 5/5] x86, nmi: Add better NMI stats to /proc/interrupts and show handlers

[Don Zickus <dzickus@redhat.com>]

On Wed, May 07, 2014 at 05:42:31PM +0200, Ingo Molnar wrote:
> 
> * Don Zickus <dzickus@redhat.com> wrote:
> 
> > The main reason for this patch is because I have a hard time knowing
> > what NMI handlers are registered on the system when debugging NMI issues.
> > 
> > This info is provided in /proc/interrupts for interrupt handlers, so I
> > added support for NMI stuff too.  As a bonus it provides stat breakdowns
> > much like the interrupts.
> > 
> > The only ugly issue is how to label NMI subtypes using only 3 letters
> > and still make it obvious it is part of the NMI.  Adding a /proc/nmi
> > seemed overkill, so I choose to indent things by one space.  Sample
> > output is below:
> > 
> > [root@dhcp71-248 ~]# cat /proc/interrupts
> >            CPU0       CPU1       CPU2       CPU3
> >   0:         29          0          0          0  IR-IO-APIC-edge      timer
> > <snip>
> > NMI:         20        774      10986       4227   Non-maskable interrupts
> >  LOC:         21        775      10987       4228  Local     PMI, arch_bt
> >  EXT:          0          0          0          0  External  plat
> >  UNK:          0          0          0          0  Unknown
> >  SWA:          0          0          0          0  Swallowed
> > LOC:      30374      24749      20795      15095   Local timer interrupts
> > SPU:          0          0          0          0   Spurious interrupts
> > PMI:         20        774      10986       4227   Performance monitoring interrupts
> > <snip>
> 
> Looks pretty useful!
> 
> The lost vertical alignment of the counts is a problem though IMHO.

Agreed!  It wasn't obvious to me at the time on how to keep that alignment
while only changing the first column.  I can look at it again, if you are
ok with the small shift in the first column.  Otherwise alternate ideas
are welcomed. :-)

Cheers,
Don