On 06/13/2011 01:54 PM, Brandeburg, Jesse wrote:
> The generator box seems to be resetting the controller (and therefore the
> link) Check out ethtool stats on both side and look for tx_timeout.
>
The emulator (igb) system is steadily increasing every
few seconds:
tx_timeout_count: 9
We are using a proprietary emulator module on this system, and it
directly sends pkts to the NIC using ndo_start_xmit(). When we
add jitter, we would tend to hold off sending pkts for a few ms and
then burst some, so perhaps we are over-driving the queues somehow.
I tried with our user-space app, but it can only handle around 850Mbps
instead of full 1G. At any rate, I cannot reproduce the problem with
just our user-space app.
I don't see any other counters of interest that are not zero
in the ethtool stats.
We did have a clean run of several hours with the in-kernel driver,
so it does seem to be software related.
I'll take a quick poke through the igb source and see if I notice
anything strange around the xmit timeout code.
Thanks,
Ben
> --
> Jesse Brandeburg's iPhone
>
> On Jun 13, 2011, at 1:35 PM, "Ben Greear"<[email protected]> wrote:
>
>> I have a traffic generator system with e1000e running pktgen, and emulator
>> (bridge-ish)
>> system with igb (3.0.19 driver). When we add jitter on the emulator,
>> and only then, we start seeing link bounces.
>>
>> If we use the stock 2.6.38.8 igb driver on the emulator, we do not see link
>> bounces. The kernel logs make me *think* that it's the generator that
>> is resetting the link, however.
>>
>> We tried two different generators, but both were e1000e NICs.
>>
>> I'm curious if anyone has any suggestions about how to tell which
>> NIC is causing the resets, and why it might be doing so.
>>
>> Here are kernel logs from the generator:
>>
>> e1000e: eth2 NIC Link is Down
>> e1000e 0000:08:00.0: eth2: Reset adapter
>> e1000e: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
>> e1000e: eth3 NIC Link is Down
>> e1000e 0000:08:00.1: eth3: Reset adapter
>> e1000e: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
>> e1000e: eth2 NIC Link is Down
>> e1000e 0000:08:00.0: eth2: Reset adapter
>> e1000e: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
>> e1000e: eth3 NIC Link is Down
>> e1000e 0000:08:00.1: eth3: Reset adapter
>> e1000e: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
>> e1000e: eth2 NIC Link is Down
>> e1000e 0000:08:00.0: eth2: Reset adapter
>> e1000e: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
>> [root@simech2 ~]# ethtool -i eth3
>> driver: e1000e
>> version: 1.2.20-k2
>> firmware-version: 5.6-2
>> bus-info: 0000:08:00.1
>>
>> And here is from the emulator:
>>
>> igb: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
>> ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
>> igb: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
>> ADDRCONF(NETDEV_CHANGE): eth3: link becomes ready
>> igb: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
>> ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
>> igb: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
>> ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
>> igb: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
>> ADDRCONF(NETDEV_CHANGE): eth3: link becomes ready
>>
>>
>> Thanks,
>> Ben
>>
>> --
>> Ben Greear<[email protected]>
>> Candela Technologies Inc http://www.candelatech.com
>>
>>
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--
Ben Greear <[email protected]>
Candela Technologies Inc http://www.candelatech.com
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