kernel: interrupt storm detected on "irq22:"; throttling interrupt source [7.0-RELEASE]

Oliver Peter lists at
Mon Sep 8 23:08:20 UTC 2008

Hi John,

Thanks for your reply.

On Mon, 8 Sep 2008 11:08:49 -0400
John Baldwin <jhb at> wrote:

> On Monday 01 September 2008 09:12:16 am Oliver Peter wrote:
> > Hi,
> >
> > For about 6 weeks I'm suffering an interrupt storm on my production
> > machine which is running 7.0-RELEASE-p3/amd64.
> >
> > The kernel is flooding my syslog with the following messages[1].
> > A full dmesg can be found here[2].
> >
> > As discribed in "Using and Debugging FreeBSD ACPI" I already tried
> > to disable apic during boot time but that's a bad idea because it
> > seems that the SATA2 onboard controller has to have apic loaded -
> > please correct me if I'm wrong.
> >
> > /boot/loader.conf:
> > 	hint.apic.0.disabled="1"
> >
> > Doesn't work for me.
> >
> > Btw. I think it's worth it to have a little note in that part of
> > the documentation which says something about possible failures
> > during the boot time.
> >
> > Thanks for any suggestions.  
> There are two possible causes of an interrupt storm:  1) some device
> is actually using IRQ 22 but FreeBSD thinks it is using something
> else.  This doesn't happen very often as it is generally a bug in the
> BIOS and one of the tables it generates.  This used to happen more
> often in older versions of FreeBSD that had bugs or limitations in
> the code that figured out which IRQ PCI devices used.

How can I find out exactly which device is using IRQ 22?
Maybe I can disable it - i.e. USB is not needed at all.

> 2) There is a
> bug in the driver for one of the devices on IRQ 22.  In this case the
> only device you have on IRQ is atapci0, so it may be a bug in the
> ata(4) driver, possibly.  You could check to see if the interrupt
> handler for the Linux driver for your chipset has extra logic
> (currently ata(4) doesn't have any chipset-specific logic for
> interrupt handlers AFAIK).  Also, you could try examining the
> interrupt status register of your controller when you are getting
> storms to see if there is a condition set that isn't being cleared by
> ata's interrupt handler.

... of course I could do that - but could you please be so kind and
explain how to do that?  :-)


Oliver PETER, email: oliver at, ICQ# 113969174
"If it feels good, you're doing something wrong."
                                      -- Coach McTavish

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