massive interrupt storm

[Murray Taylor]

Hi all,

We have just purchased some servers with a view to
using them as firewalls within our WAN, and have discovered that
they are suject to a massive interrupt storm on IRQ17.

systat -v is showing 59000 -> 63000 interrupts continuously
on this IRQ, and 90%->98% Interrupt CPU usage  

The server specs are 

Model: IBM x3250 M2
IBM MT code: 4190
CPU : Core 2 Duo, 
Has SAS RAID module fitted to mobo
2 SATA drives in RAID 1

No mobo PS2 ports at all
4 USB port on mobo
2 Broadcom NIC on mobo
1 Gb RAM fitted as 2 512M sticks

PCI Express Bus - No cards installed


It seem to be related to one of the PCI busses as bge1 doesnt
come up in the dmesg lists and that is on (i think) pcib1.


Big Note: this storm activity is apparent on 4.11, 6.2 and 7.0 ...

kernel is GENERIC in all test cases.

The boxen work, just v e r y   s l o w l y ...

ideas ?

Murray Taylor

Special Projects Engineer
Bytecraft Systems

--
"Any intelligent fool can make things bigger and more complex... It
takes a
touch of genius - and a lot of courage to move in the opposite
direction."
--Albert Einstein 


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