Xen
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xen-devel
RE: [Xen-devel] Seeking performance numbers for flip vs. copy
This data was for transferring 1500 byte data packets with
TCP. Note that the difference of performance on transmit is due to the receive
of ACK packets (small size).
The domains were not explicitly pinned, but since there
were only two domains (dom0 and domU) in a 4-cpu machine they were running on
different CPUs.
Renato
Thanks so much - this is very
helpful.
For comparison purposes, it
would be great to know the message size. Also wondering if doms were
pinned?
Regards, Sue
_______________________________________________________________
Suzanne
McIntosh
IBM T.J. Watson Research
Center
Secure Systems and Services
"Santos, Jose Renato G"
<joserenato.santos@xxxxxx> Sent by: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
03/26/2007 06:25 PM
To
Suzanne
McIntosh/Watson/IBM@IBMUS
cc
Xen Development Mailing List
<xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject
RE: [Xen-devel] Seeking
performance numbers for flip vs. copy
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From:
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
[mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx]
On Behalf Of Suzanne
McIntosh
Sent: Monday, March 26, 2007 12:48 PM
To: xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: Suzanne
McIntosh
Subject:
[Xen-devel] Seeking performance numbers for flip vs.
copy
Hi,
I am looking for performance numbers comparing the network
driver flip vs.
copy feature
on a
32-bit machine. Could not locate this info in Xen archives.
Would
appreciate any help.
Thanks, Sue
_______________________________________________________________
Suzanne McIntosh
IBM T.J. Watson Research
Center
Secure
Systems and Services
Here is some old data that I have for comparing page flip with
copy.
Note that this for Xen unstable as of October 3, 2006.
I
don't more recent data, but I believe the relative performance should
not
have changed much, although the absolute numbers may be
different
now.
I hope this helps
Renato
> Here are
the results comparing copy and page flip.
> These results were using
netperf TCP_STREAM test which use large size
> packets.
> I run
experiments for receiving and transmiting to from/to a external
>
client.
> The results show that copying use less cycles than page flip
but dom0
> has higher utilization (due to the copy).
> This
caused dom0 cpu to saturate and reduced the throuhgput slightly
in
>
my machine. I have a 4way Intel Xeon 2.8Ghz with 4GB of RAM
(each
domain
> is using 512 MB of RAM).
> Copy is also better
for the transmit experiment since the overhead for
> processing ACKs
is reduced.
>
> I will work on the transmit side optimizations
starting tomorrow.
>
> Regards
>
> Renato
>
> =======================================================
>
receive:
>
------------------------------------------------------_
>
| |
| cycles/packet |
>
| Rate | CPU utilization |
(thousands) |
> | Mb/s
| dom0 dom1 tot | dom0 dom1 tot
|
>
-------------------------------------------------------
> flip | 941.34
| 84.2% 76.3% 160.4% | 30.1 27.2 57.3 |
> copy | 907.71 |
99.7% 45.2% 144.9% | 36.9 16.7 53.6 |
>
-------------------------------------------------------
>
>
transmit:
> ------------------------------------
>
| |
|
> | Rate |
CPU utilization |
> | Mb/s
| dom0 dom1 tot |
>
------------------------------------
> flip | 941.31 | 49.6% 43.9%
93.5% |
> copy | 941.30 | 45.2% 34.5% 79.7% |
>
------------------------------------
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