6.2 SHOWSTOPPER - em completely unusable on 6.2

[Scott Long]

Volker wrote:
> On 37378-12-23 20:59, Patrick M. Hausen wrote:
> 
>>Hello!
>>
>>
>>>Well, the best I can say at the moment is, "Wow."  =-(  I guess the 
>>>thing to do here is to figure out if the problem lies with the em 
>>>interrupt handler not getting run, or the taskqueue not getting run.
>>
>>I helped Pyun with some debugging by providing ssh access to
>>a machine showing the (seemingly) same problem.
>>
>>At first he thought the interrupt handler of the em driver was
>>the culprit, but we applied quite a few patches and tested
>>afterwards - seems like the driver is not the cause.
>>
>>On -stable occasionally other people complained about very similar
>>looking problems with bge and other drivers. My guess is, though 
>>I'm not a kernel developer, just an experienced admin, that
>>em stands out as problematic just by coincidence. Certain onboard
>>network components tend to come with certaiin chipsets and certain
>>architectures.
>>
>>So, Pyun suggested it was a problem with the taskqueue that was
>>introduced some time between 6.0 and 6.1.
>>
>>With my system (Tyan GT20 B5161G20) the problem shows when there
>>is heavy disk and cpu activity, like "make buildworld".
>>I made sure that the em interface doesn't share an interrupt
>>with the SATA controller. When the problem occurs, I get the
>>well known "watchdog timeout" messages and then the system's
>>network activity over that interface freezes completely for
>>a couple of minutes.
>>Usually the system recovers after a while without reboot or
>>other measures.
>>
> 
> 
> Strange... I've seen exactly that on a (recent) RELENG_6 box but
> using a dirty old USB 1.1 NIC (aue). I've seen DOWN and UP messages
> (mostly while rebuilding kernel + world + ports) on the console all
> the time (but did not care about).
> 
> The machine in question is an Athlon XP-64 Socket 939, Asus A8N-VM
> CSM. The USB ethernet NIC is a low budget ADMtek device. My
> observations are probably not related to your issues but maybe a
> sign of not really being a driver issue or not GigE related.
> 
> Greeting,
> 
> Volker

As soon as I can locate the O/U/EHCI register docs, I'll crank out a
patch for everyone to try.  If that works then I'll give the same 
treatment to ichsmb.

Scott