interrupt storm on ahci

[Steve Wills]

On Sat, Jun 07, 2014 at 02:53:05PM -0700, Neel Natu wrote:
> Hi Steve,
> 
> On Sat, Jun 7, 2014 at 2:28 PM, Peter Grehan <grehan at freebsd.org> wrote:
> > Hi Steve,
> >
> >
> >> I'm running a FreeBSD guest in bhyve on a FreeBSD host. Both are running
> >> FreeBSD CURRENT, r266947. I've gotten this message about 12 times since
> >> boot:
> >>
> >> interrupt storm detected on "irq268:"; throttling interrupt source
> >>
> >> vmstat -i shows:
> >>
> >> irq268: ahci1                  236514222        839
> >>
> >> ahci1 is the second disk connected to the system:
> >>
> >> ahci1: <Intel ICH8 AHCI SATA controller> mem 0xc0002400-0xc00027ff irq 18
> >> at device 4.0 on pci0
> >>
> >> The VM itself runs poudriere and was building a bunch of packages. At the
> >> moment, the VM seems to be in a rather odd state. The poudriere jails are
> >> running, but not doing anything. Ideas?
> >
> >
> >  Is this an 8.* host ? I don't believe AHCI has MSI support on that version,
> > and AHCI legacy interrupts haven't had a huge amount of testing under load.
> >
> >  If it is 8.*, I'd recommend using virtio-blk for the block device until we
> > can work out what's going wrong.
> >

Both the host and guest are running FreeBSD CURRENT r266947.

> The KTR trace would be useful to figure out what's happening.
> 
> To do that you can compile the host kernel and vmm.ko with the
> following options:
> options KTR
> options KTR_MASK=(KTR_GEN)
> options KTR_ENTRIES=(4*1024*1024)
> 
> And when you see the interrupt storm message in the guest you can execute:
> sudo ktrdump -cto /tmp/ktrdump.out

Ok, I'll work on getting that added to the host.

Thanks,
Steve