Re: Poor network performance in domU in unstable

[Jacob Gorm Hansen <jacobg@diku.dk>]

Jacob Gorm Hansen wrote:
> hi,
> 
> with unstable as of April 21st, I am getting fairly bad networking 
> performance in my domUs, e.g 125Mbits/s TCP with iPerf over a gigabit 
> link, where dom0 gets around 700Mbits/s.
> 
> This is with a non-debug build of Xen, with a bridged setup created with 
> vmtools, and both with and without use of grant tables.
> 
> If I run Xen with hyperthreading enabled, the figure improves somewhat, 
> to 165Mbits/s in domU.
> 
> Is anyone else seeing the same behaviour with unstable? Is there some 
> magic switch I need to flip (that perhaps vmtools does not know about) 
> to prevent domain I/O being throttled by Xen?

This seems to have been a configuration issue, as instead of migrating 
my old .config files using the arch/xen/config/* files got domU back to 
normal performance.

Thanks,
Jacob