High interrupt rate on a PF box + performance

[Damien Fleuriot]

On 1/27/11 11:03 AM, Bartosz Stec wrote:
> W dniu 2011-01-27 10:57, Damien Fleuriot pisze:
>> Hello list,
>>
>> I have a problem with interrupts, network cards, and PF performance.
>>
> I think you should try with polling(4) enabled and probably increase
> kernel.hz i sysctl.conf :)
> 


As a matter of fact, we tried polling on the backup firewall yesterday
with the following kernel options:
options DEVICE_POLLING
options HZ=1000




This had disastrous results.
First, our LAN and DMZ interfaces (bce0 and 1) do not support polling,
so no change here.
Second, the WAN interface (igb0) supports polling but that caused
problems with carp0 and the physical interface resetting itself for god
knows what reason:


carp0: link state changed to DOWN
carp0: INIT -> BACKUP
igb0: link state changed to UP
carp0: link state changed to DOWN
carp0: link state changed to UP
carp0: MASTER -> BACKUP (more frequent advertisement received)
carp0: link state changed to DOWN
carp0: link state changed to UP
igb0: Watchdog timeout -- resetting
igb0: Queue(1) tdh = 57, hw tdt = 57
igb0: TX(1) desc avail = 967,Next TX to Clean = 0
igb0: link state changed to DOWN
carp0: link state changed to DOWN
carp0: INIT -> BACKUP
igb0: link state changed to UP
carp0: link state changed to DOWN
carp0: link state changed to UP
carp0: link state changed to DOWN
igb0: Watchdog timeout -- resetting
igb0: Queue(3) tdh = 5, hw tdt = 5
igb0: TX(3) desc avail = 1019,Next TX to Clean = 0
igb0: link state changed to DOWN
igb0: link state changed to UP
igb0: Watchdog timeout -- resetting
igb0: Queue(2) tdh = 53, hw tdt = 53
igb0: TX(2) desc avail = 971,Next TX to Clean = 0
igb0: link state changed to DOWN
igb0: link state changed to UP
igb0: Watchdog timeout -- resetting
igb0: Queue(2) tdh = 19, hw tdt = 19
igb0: TX(2) desc avail = 1005,Next TX to Clean = 0
igb0: link state changed to DOWN
igb0: link state changed to UP