Re: [Xen-devel] Sending packet at fixed rate really bad performance

[Marco Tizzoni <marco.tizzoni@xxxxxxxxx>]

On Mon, Sep 28, 2009 at 4:17 PM, Konrad Rzeszutek Wilk
<konrad.wilk@xxxxxxxxxx> wrote:
> Lets narrow this down a bit.  You are comparing two different systems
> with potentially different interfaces. Lets concentrate on one machine
> first. Is the performance on your Athlon 64 without Xen (meaning you
> boot without Xen) in the same ball-park figure?
> I want to make sure we can eliminate the hardware being at fault here.

I've already done many tests to isolate the problem before writing here.
I've tried to use a different nic, different LAN, different switch and
loopback as well, same results.
Anyway forget aboout Athlon and let compare the same software, on the
same hardware with linux and xenolinux.

I've connected two pc running linux via a cross-cable and made some
tests. The test achieves good results in this case for rate over 10k
packets/second.
On xenolinux (credit and sedf behaviour the same) the performance are
really bad, 250 packets/second (as before).

Also I've just modified my software to not send packets, but simply
count, so no sendto() is involved. Same low rate.

May be there's something wrong in my code (not yet finished). Attached
you can find it if you want have a look or try to reproduce this
issue.

thx,
Marco

Attachment: main.c.gz
Description: GNU Zip compressed data

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