Intel 82580 Stats every other second

[nullivex]

Hello,

I have been searching around for a while on this and havent found anyone else reporting it which is strange.

With certain NIC's and most definitely Intel 82580 it reports stats every other second and then it seems these are a total of the last 2 seconds.

I have attached a screenshot of the issue.

If there is a simple fix please let me know.

Thanks

[dagwieers]

It's a driver issue. We have had reports before (not sure if it was this driver) and using a newer driver helped in those cases. If you take a 2 or more second average you'll get correct numbers, it's just that the 1 second granularity fails because the driver doesn't update the counters every second :-(

[nullivex]

I had a feeling that was the case.

Im not ultra interested in compiling a new driver just to get around that so I will probably just bump the update interval to 2 on these machines.

Thanks for the help.

[dagwieers]

An interesting fact is that if you would enable the interrupt stats (and you look in /proc/interrupts the interrupt of your NIC), you'll see that the number of interrupts are updated every second. Which proves that it is not a hardware issue (the hardware is sending/receiving data as fast as it can) but the driver simply doesn't do the bookkeeping every second.

If the interrupt would also skip every second, there might be a more severe hardware/driver issue.

[nullivex]

I just wanted to note that this was fixed in the latest Debian build for Wheezy with the kernel below.

Linux s2 3.2.0-4-amd64 #1 SMP Debian 3.2.41-2+deb7u2 x86_64 GNU/Linux

With these controllers

01:00.0 Ethernet controller: Intel Corporation 82580 Gigabit Network Connection (rev 01)
01:00.1 Ethernet controller: Intel Corporation 82580 Gigabit Network Connection (rev 01)

[dagwieers]

Thanks for the feedback !