interrupt storms

[Daniel Gerzo]

Hello,

 recently, we have inserted a new NIC into our machine, and after a
 few hours of operation, the machine starts to suffer from interrupt
 storms.

Mar 17 21:05:24 ha-web1 kernel: interrupt storm detected on "irq22:"; throttling interrupt source
Mar 17 21:05:54 ha-web1 last message repeated 30 times
Mar 17 21:07:54 ha-web1 last message repeated 120 times
Mar 17 21:17:54 ha-web1 last message repeated 600 times
Mar 17 21:27:54 ha-web1 last message repeated 600 times

 Here is the output of vmstat -i:

interrupt                          total       rate
irq1: atkbd0                           5          0
irq9: acpi0                            1          0
irq16: ohci0                           1          0
irq17: ohci1 ohci3                     1          0
irq18: ohci2 ohci4                     1          0
irq20: em0                      22617825       1714
irq22: em1 atapci0             699549409      53036
cpu0: timer                     26380374       2000
cpu1: timer                     26380325       2000
Total                          774927942      58751

 Any idea, why em1 and atapci0 share the same irq? I don't think this
 is correct. Is there some way how to work this around?

 Thanks.

-- 
Best regards,
 Daniel                          mailto:danger at FreeBSD.org