On Thursday, 15. January 2015 07:25:32 Eric Dumazet wrote:

On Thu, 2015-01-15 at 15:58 +0100, Thomas Jarosch wrote:

quoted

A colleague mentioned to me he saw the "Hardware Unit Hang" message
every
few days even running on kernel 3.4 (without your patch). Basically I'm
testing now if that's still the case with 3.19-rc4+ or not.

I'm all for fixing the root cause. I'm just interested if the e1000e
hang can even be triggered when using a max frag page size of 4096.
So far it transferred 751.6 GiB without a hiccup.

You told it was forwarding setup.

1) What is the NIC receiving traffic.
2) What happens if you disable GRO on it ?

one more interesting thing happened: On one production machine,
again an Intel DH61CR board, the issue was triggered even with TSO disabled.
My colleague tried to disable GRO + GSO on the e1000e adapter, too,
though not on the other interfaces.

It's strange the issue appears with TSO disabled,
that worked for three other production level machines.

We've emergency-installed the "4096" max frag page size workaround
for now as fifty people were a bit unhappy without network access... :D

Cheers,
Thomas