157k interrupts per second causing 60% CPU load on idle system

[Matt Thyer]

On 20 March 2012 21:12, Ivan Voras <ivoras at freebsd.org> wrote:

> On 20/03/2012 06:26, Matt Thyer wrote:
> > I've upgraded my FreeBSD-STABLE NAS from r225723 (22nd Sept 2011) to
> > r232477 (4th Mar 2012) and am finding that a system process called "intr"
> > is now constantly using about 60% of 1 CPU starting a short time after
> > reboot (possibly triggered by use of the samba server).
> >
> > When this starts, systat -vm 1 says that the system is 85% idle and 14%
> > interrupt handling.
> > It says that there's around 157k interrupts per second.
> >
>
> Ok, but *which* interrupt is getting triggered? Please send the output
> of "vmstat -i".
>
>
> interrupt                          total       rate
irq16: uhci0+                 3392184862     126692
cpu0: timer                     53549677       1999
irq256: mps0                     2643187         98
irq257: re0                      5508108        205
irq258: ahci0                     160717          6
cpu1: timer                     53525300       1999
cpu2: timer                     53525300       1999
cpu3: timer                     53525296       1999
Total                         3614622447     134999