[arch-general] High CPU on one core, but unable to find process responsible

[David Rosenstrauch]

On 03/12/2018 09:56 PM, Carsten Mattner via arch-general wrote:
> Any BIOS updates or kernel updates recently (4.15.8)?
> 
> Try with 3.16 or 4.9 or another old lts kernel from archive.archlinux.org
> just for testing (not production).
> 
> It's more likely that the kernel regressed rather than IRQ issues popping
> up suddenly. It's possible but less likely.

No BIOS updates.  As far as kernel updates, I do those all the time, so 
not sure that would be the cause.


After doing some digging, though, I did "cat /proc/interrupts", and this 
line stood out, for having an astronomically high number:

            CPU0       CPU1       CPU2       CPU3
...
  16: 2424156658          0          0          0   IO-APIC  16-fasteoi 
  uhci_hcd:usb5, parport1


I have an old PCI card in the machine that's powers an old parallel port 
printer I used to use with it.  Perhaps that's failing.  I don't need 
the card anymore, so I might as well try taking it out and see if that
makes things better.  If not, I'll be back.  :-)

Thanks,

DR