Re: [dpdk-dev] generic load balancing

["François-Frédéric Ozog" <ff@ozog.com>]

Hi,

As far as I can tell, this is really hardware dependent. Some hash functions
allow uplink and downlink packets of the same "session" to go to the same
queue (I know Chelsio can do this).

For the Intel card, you may find what you want in:
http://www.intel.com/content/www/us/en/ethernet-controllers/82599-10-gbe-con
troller-datasheet.html

Other cards require NDA or other agreements to get details of RSS.

If you have a performance problem, may I suggest you use kernel 3.10 then
monitor system activity with "perf" command. For instance you can start with
"perf top -a" this will give you nice information. Then your creativity will
do the rest ;-) You may be surprised what comes on the top hot points...
(the most unexpected hot function I found here was Linux syscall
gettimeofday!!!)

François-Frédéric

> -----Message d'origine-----
> De : dev [mailto:dev-bounces@dpdk.org] De la part de Michael Quicquaro
> Envoyé : mercredi 4 décembre 2013 18:53
> À : dev@dpdk.org
> Objet : [dpdk-dev] generic load balancing
> 
> Hi all,
> I am writing a dpdk application that will receive packets from one
> interface and process them.  It does not forward packets in the
traditional
> sense.  However, I do need to process them at full line rate and therefore
> need more than one core.  The packets can be somewhat generic in nature
and
> can be nearly identical (especially at the beginning of the packet).  I've
> used the rxonly function of testpmd as a model.
> 
> I've run into problems in processing a full line rate of data since the
> nature of the data causes all the data to be presented to only one core.
I
> get a large percentage of dropped packets (shows up as Rx-Errors in "port
> stats") because of this.  I've tried modifying the data so that packets
> have different UDP ports and that seems to work when I use --rss-udp
> 
> My questions are:
> 1) Is there a way to configure RSS so that it alternates packets to all
> configured cores regardless of the packet data?
> 
> 2)  Where is the best place to learn more about RSS and how to configure
> it? I have not found much in the DPDK documentation.
> 
> Thanks for the help,
> - Mike