public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
* Windows 2003: ping -n doesn't wait
@ 2009-01-20 14:53 Sven Rudolph
  2009-01-21 14:05 ` Dor Laor
  2009-01-23 20:55 ` Marcelo Tosatti
  0 siblings, 2 replies; 6+ messages in thread
From: Sven Rudolph @ 2009-01-20 14:53 UTC (permalink / raw)
  To: kvm

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

  Ping-Statistik fr 127.0.0.1:
      Pakete: Gesendet = 3, Empfangen = 3, Verloren = 0 (0% Verlust),
  Ca. Zeitangaben in Millisek.:
      Minimum = -613ms, Maximum = -465ms, Mittelwert = 1431655251ms

  [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=14699ms TTL=128
  Antwort von 127.0.0.1: Bytes=32 Zeit=14699ms TTL=128
  Antwort von 127.0.0.1: Bytes=32 Zeit=14699ms TTL=128

  Ping-Statistik fr 127.0.0.1:
      Pakete: Gesendet = 3, Empfangen = 3, Verloren = 0 (0% Verlust),
  Ca. Zeitangaben in Millisek.:
      Minimum = 14699ms, Maximum = 14699ms, Mittelwert = 14699ms

This makes the problem disappear:
- -smp 1

And these do not make the problem disappear:
- -no-kvm-irqchip
- -no-kvm-pit

Testing with -no-kvm makes no sense because -no-kvm only works with
one CPU (and using "-smp 4 -no-kvm" causes an immediate segfault).

In addition I tried the -clock options. hpet and rtc didn't run
("could not initialize alarm timer"); and dynticks and unix didn't
make the problem disappear.

Ideas, hints, or requests for more info?

	Sven



^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2009-01-26 17:09 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-01-20 14:53 Windows 2003: ping -n doesn't wait Sven Rudolph
2009-01-21 14:05 ` Dor Laor
2009-01-23 16:45   ` Marcelo Tosatti
2009-01-23 20:55 ` Marcelo Tosatti
2009-01-23 23:53   ` Dor Laor
2009-01-26 17:09   ` Sven Rudolph

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox