[dpdk-dev] [PATCH] app/testpmd: Document what the application does.

[Ben Pfaff]

On Fri, Sep 10, 2021 at 11:14:26PM +0200, Thomas Monjalon wrote:
> 10/09/2021 19:57, Ben Pfaff:
> > I could not find anything in the documentation that says what
> > testpmd does.  This should save other people time trying to
> > figure that out in the future.
> 
> Good move indeed :)
> 
> > --- a/doc/guides/testpmd_app_ug/run_app.rst
> > +++ b/doc/guides/testpmd_app_ug/run_app.rst
> > @@ -15,6 +15,12 @@ a list of available EAL command-line options.
> >  Testpmd Command-line Options
> >  ----------------------------
> >  
> > +By default, testpmd receives packets on each configured port and
> > +forwards the received packets to its paired port.  Ports 0 and 1 are
> > +paired, as are ports 2 and 3, and so on.  With an odd number of ports,
> > +the last port is paired with itself: packets received on the port are
> > +sent back out on the same port.
> 
> So the intent is to say what is the default behaviour?

I am not sure of the full extent of the program's possible behavior,
because it has many, many options.  I didn't want to try to go beyond
what I understood it to do.

> We could also update the introduction which is outdated:
> "
> The testpmd application can be used to test the DPDK
> in a packet forwarding mode and also to access NIC hardware features
> such as Flow Director.
> It also serves as a example of how to build a more fully-featured
> application using the DPDK SDK.
> "
> 
> The last sentence should be removed.
> The first sentence is a bit outdated.
> We should say "testpmd is a tool to test ethdev NIC features".
> 
> May I take the opportunity of this patch to improve this intro as well?

I would rather have updated the introduction, but I wasn't sure that it
was wrong.  Thanks for the help.  I'll post a v2.