Re: >100K interrupts/s on IOAPIC 0 Pin 9
Thor Lancelot Simon <tls <at> rek.tjls.com>
2007-09-11 20:14:20 GMT
On Tue, Sep 11, 2007 at 05:28:02PM +0200, Edgar Fu? wrote:
[reformatted to not have lines hundreds of characters long; please,
it's hard to read your email if you don't break lines before 80
> I have a freshly installed 4.0_RC2/i386 system where the CPU spends
> more than 84% in interrupt mode when the machine is idle. With
> sysstat vm, I notice ~106000 interrupts on ioapic0 pin 9. On the
> other hand, dmesg doesn't show anythin interrupting on that pin.
> Any idea how to track this down? I've tracked down some interrupt
> problems on an amd64 system some months ago, but forgotten most
> of it in the meantime. Please cc: me since I'm not subscribed to
> port-i386, only port-amd64.
This is almost certainly an issue with the ACPI system-controller
interrupt, which is misconfigured at boot time by many systems.
There have been several efforts to add code to NetBSD to fix this
but I don't believe any have been committed as each turned out to
be not quite right in some way.
A workaround may be to turn off ACPI if you have it turned on, or
on if you have it turned off.
Thor Lancelot Simon tls <at> rek.tjls.com
"The inconsistency is startling, though admittedly, if consistency is to
be abandoned or transcended, there is no problem." - Noam Chomsky