Re: Strange error in domU after dom0 update

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 10/29/09 04:14, Andreas Florath wrote:
> Hello!
>
> The yesterdays patch fixed the tcp performance problem.
>
> Run some tests:
>
> Setup:
>
> - 1- dom0 kernel 2.6.26 hardware A
> - 2- dom0 kernel 2.6.26 hardware B
> - 3- domU kernel 2.6.26 running on -1-
> - 4- domU kernel 2.6.26 running on -2-
>
> - 5- dom0 kernel 2.6.31.4 current pv_ops hardware C
> - 6- dom0 kernel 2.6.31.4 current pv_ops hardware D
> - 7- domU kernel 2.6.26 running on -5-
> - 8- domU kernel 2.6.26 running on -6-
>
> All hardware boxes are exactly the same hardware:
> P4 2,8GHz with 1G RAM and Gigabit Ethernet
>
> nuttcp
>
> Results (average of three independent tests without
> any other load):
>
>                  ->     /    <-
>
> - 1- <-> - 2- :  255 Mbps /  219 Mbps
> - 1- <-> - 3- :   52 Mbps /   75 Mbps
> - 1- <-> - 4- :  183 Mbps /  146 Mbps
> - 3- <-> - 4- :  289 Mbps /  271 Mbps
>
> - 5- <-> - 6- :  693 Mbps /  675 Mbps
> - 5- <-> - 7- : 1045 Mbps / 1227 Mbps
> - 5- <-> - 8- :  397 Mbps /  668 Mbps
> - 7- <-> - 8- :  385 Mbps /  365 Mbps
>
> So the speed increased.
>
>>
>> Yes, that's the netchannel2 merge.  Do you have it enabled in your
>> config?  If it is not enabled then it definitely shouldn't have any
>> effect on your system.  If it is enabled then it could be buggy because
>> it is very new code.
> netlink2 seams enabled (is set in the kernel config). Looks that this
> is done by default.

That's an error; it definitely shouldn't be on by default.   What
happens if you disable it?

> The only remaining issue are now the millions of log messages:
> netfront: rx->offset: 0, size: 4294967295
> which occur only on the 2.6.31.4 pv_ops systems - and, what
> I think at the moment, only for iSCSI traffic.

If this is still present when you disable netchannel2 then I'll revert
the merge.

Either way, Steven, could you look at this?

Thanks,
    J