On Wed, Sep 30, 2009 at 8:37 AM, Pasi Kärkkäinen <
pasik@xxxxxx> wrote:
> On Wed, Sep 30, 2009 at 08:33:19AM +0200, Marco Tizzoni wrote:
>> I experienced the same problem with netperf and with hping also. In
>> general every tool that sends packet at fixed rates seems to suffer this
>> problem. If you use the flood option ( sends packets as fast as possible -
>> for example 'ping -f' or 'hping3 -f') instead of a fixed rate the rate
>> become much higher. What I discovered is this issue should be related to
>> Xen's signal handling/delivery.
>> Netperf use setitimer() to send packets at fixed rate. In my experience on
>> dom0/U, with no load, Xen
cannot go over 250 signals per second. Because
>> netperf use signal wakeup the function that send packets I think your
>> problem can be related to this issue. If you want to be sure, count the
>> average number of packet per seconds. It should be about 250 packets/s
>> (not more).
>
>
> 250 per second.. sounds like kernel HZ value?
Yes, infact I'm going to test it with 1000Khz. Stay tuned.
:)
m-
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