Re: Windows 2003: ping -n doesn't wait

[Marcelo Tosatti <mtosatti@redhat.com>]

On Tue, Jan 20, 2009 at 03:53:06PM +0100, Sven Rudolph wrote:
> Hello,
> 
> first the facts required by bug reporting guidelines:
> 
> - two Quad-Core AMD Opteron(tm) Processors 2352
> - kvm-83 (both kernel and userland)
> - Host kernel: 2.6.28.1, x86_64 
> - guest:
>   - 4 CPUs assigned to this guest (-smp 4)
>   - Microsoft Windows 2003 Server, Standard Edition, Service Pack 2
> - qemu command line:
>   qemu-system-x86_64 -m 4096 -boot c -hda hda.dat -smp 4 \
>     -net nic,macaddr=00:50:56:24:0b:37,model=virtio \
>     -net tap,ifname=vm03,script=no,downscript=no
> 
> The problem: When running "ping -n 3 localhost" on the guest it should
> wait one second between each ping request and the time needed should
> be non-negative and below 10 ms. Instead, ping does not actually wait
> between sending the packets, and the time for the requests ist often
> displayed to be too large or negative. Simple examples:
> 
>   [WinNT] ping -n 3 localhost
> 
>   Ping wird ausgefhrt fr localhost [127.0.0.1] mit 32 Bytes Daten:
> 
>   Antwort von 127.0.0.1: Bytes=32 Zeit=-465ms TTL=128
>   Antwort von 127.0.0.1: Bytes=32 Zeit=-613ms TTL=128
>   Antwort von 127.0.0.1: Bytes=32 Zeit=-465ms TTL=128

Sven, Dor,

Can you try to use the AMD CPU drivers for Windows? 

Take a look at http://forums.citrix.com/thread.jspa?threadID=93813

http://www.therightstuff.de/2007/06/05/The-Case-Of-The-Negative-Ping.aspx

I don't doubt the KVM tsc syncing code for AMD is not involved, though.