RE: [PATCH 00/12] add packet generator library and example app

["Randles, Ronan" <ronan.randles@intel.com>]

I'd be inclined to agree with you on the move to the app dir. The example app could be turned into more of a fully-fledged app than just an example app. I think the final decision on that would fall to @Van Haaren, Harry on that

-----Original Message-----
From: Richardson, Bruce <bruce.richardson@intel.com> 
Sent: Tuesday, December 14, 2021 2:58 PM
To: Randles, Ronan <ronan.randles@intel.com>
Cc: dev@dpdk.org; Van Haaren, Harry <harry.van.haaren@intel.com>
Subject: Re: [PATCH 00/12] add packet generator library and example app

On Tue, Dec 14, 2021 at 02:12:30PM +0000, Ronan Randles wrote:
> This patchset introduces a Gen library for DPDK. This library provides 
> an easy way to generate traffic in order to test software based network components.
> 
> This library enables the basic functionality required in the traffic generator.
> This includes: raw data setting, packet Tx and Rx, creation and 
> destruction of a  Gen instance and various types of data parsing.
> This functionality is implemented in "lib/gen/rte_gen.c". IPv4 parsing 
> functionality is also added in "lib/net/rte_ip.c", this is then used 
> in the gen library.
> 
> A sample app is included in "examples/generator" which shows the use 
> of the gen library in making a traffic generator. This can be used to 
> generate traffic by running the dpdk-generator generator executable. 
> This sample app supports runtime stats reporting (/gen/stats) and line 
> rate limiting (/gen/mpps,<target traffic rate in mpps>) through telemetry.py.
> 
> As more features are added to the gen library, the sample application 
> will become more powerful through the "/gen/packet" string parameter 
> (currently supports IP and Ether address setting). This will allow 
> every application to generate more complex traffic types in the future 
> without changing API.
> 
> Harry van Haaren (6):
>   gen: add files for initial traffic generation library
>   gen: add basic Rx and Tx routines and tests
>   gen: add raw packet data API and tests
>   gen: add parsing infrastructure and Ether protocol
>   gen: add gen IP parsing
>   examples/generator: import code from basicfwd.c
> 
> Ronan Randles (6):
>   net: add string to IPv4 parse function
>   net: add function to pretty print IPv4
>   examples/generator: enable gen library for traffic gen
>   examples/generator: telemetry support
>   examples/generator: link status check added
>   examples/generator: line rate limiting
> 
>  app/test/meson.build           |   4 +
>  app/test/test_gen.c            | 184 +++++++++++
>  app/test/test_net.c            |  87 ++++++
>  doc/api/doxy-api-index.md      |   3 +-
>  doc/api/doxy-api.conf.in       |   1 +
>  examples/generator/main.c      | 483 ++++++++++++++++++++++++++++
>  examples/generator/meson.build |  13 +
>  examples/meson.build           |   1 +
>  lib/gen/meson.build            |   6 +
>  lib/gen/rte_gen.c              | 553 +++++++++++++++++++++++++++++++++
>  lib/gen/rte_gen.h              | 114 +++++++
>  lib/gen/version.map            |  10 +
>  lib/meson.build                |   1 +
>  lib/net/meson.build            |   1 +
>  lib/net/rte_ip.c               |  58 ++++
>  lib/net/rte_ip.h               |  38 +++
>  lib/net/version.map            |   9 +
>  17 files changed, 1565 insertions(+), 1 deletion(-)

I think this is great to see, and sounds a good addition to DPDK. One thing to address in any v2 is to add more documentation for both the library and the example app. You need a chapter on the lib added to the programmers guide to help others use the library from their code, and a chapter on the generator example in the example apps guide.

More general question - if we do have a traffic generator in DPDK, would it be better in the "app" rather than the examples one? If it's only going to ever stay a simple example of using the lib, examples might be fine, but I suspect that it will get quite complicated if people start using it and adding more features, in which case a move to the "app" folder might be more appropriate. Thoughts?

/Bruce