On 09/04/2013 07:59 PM, Daniel Borkmann wrote:

On 09/04/2013 01:27 PM, Eric Dumazet wrote:

quoted

On Wed, 2013-09-04 at 03:30 -0700, Eric Dumazet wrote:

quoted

On Wed, 2013-09-04 at 14:30 +0800, Jason Wang wrote:

quoted

quoted

And tcpdump would certainly help ;)

See attachment.

Nothing obvious on tcpdump (only that lot of frames are missing)

1) Are you capturing part of the payload only (like tcpdump -s 128)

2) What is the setup.

3) tc -s -d qdisc

If you use FQ in the guest, then it could be that high resolution timers
have high latency ?

Probably they internally switch to a lower resolution clock event
source if
there's no hardware support available:

  The [source event] management layer provides interfaces for hrtimers to
  implement high resolution timers [...] [and it] supports these more
advanced
  functions only when appropriate clock event sources have been
registered,
  otherwise the traditional periodic tick based behaviour is retained.
[1]

[1] https://www.kernel.org/doc/ols/2006/ols2006v1-pages-333-346.pdf 

Maybe, AFAIK, kvm-clock does not provide a clock event, only a pv
clocksource were provided.