Re: [dpdk-dev] [pull-request] next-tm 17.08 pre-rc1

[Thomas Monjalon <thomas@monjalon.net>]

10/07/2017 17:46, Dumitrescu, Cristian:
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > 10/07/2017 15:21, Dumitrescu, Cristian:
> > > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > > 10/07/2017 12:55, Dumitrescu, Cristian:
> > > > > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > > > > 2/ Some functions are exposed in the API to query the ops.
> > > > > > It seems dangerous and useless:
> > > > > > 	- rte_eth_dev_tm_ops_get
> > > > > > 	- rte_tm_ops_get
> > > > >
> > > > > Thomas, hopefully this is a misunderstanding on your side :(((.
> > > >
> > > > Don't worry :)
> > > >
> > > > > This is a critical point that we debated ad nauseam on this email list
> > (RFC, V1
> > > > -V6) and privately as well. You were included in the conversation, you
> > also
> > > > provided feed-back that we incorporated in the code, as documented in
> > the
> > > > patchset history log.
> > > > >
> > > > > This is simply the mechanism that we (including you) agreed to use for
> > > > modularizing the DPDK ethdev by adding new functionality in a modular
> > plug-
> > > > in way using separate namespace. This is the exact clone of the same
> > > > mechanism that rte_flow is using and was merged in DPDK release 17.02.
> > > > Why this change on the fundamentals now?
> > > > >
> > > > > Hopefully, it is just misunderstanding.
> > > >
> > > > I mean that only the drivers need to get the ops.
> > > > The applications are using some dedicated functions rte_tm_* , right?
> > > > So the applications does not need direct ops access with
> > > > rte_eth_dev_tm_ops_get()?
> > > > Sorry if it is my misunderstanding.
> > > >
> > > > About rte_tm_ops_get, I don't remember why I talked about it.
> > > > It seems exposed only to drivers. My mistake. No issue there.
> > >
> > > OK, so we're good then?
> > 
> > Not exactly. In my understanding, rte_eth_dev_tm_ops_get() is useless.
> > Should it be removed then?
> 
> Why do you think it is useless? How would the driver get the function specific (i.e. rte_flow, rte_tm, ...) operations structure?

The drivers get the structure via rte_tm_ops_get() function which is
in the well named file rte_tm_driver.h
My question is about rte_eth_dev_tm_ops_get() function which is
in the file rte_ethdev.h.
Please explain the difference between both functions and why
rte_eth_dev_tm_ops_get() is needed.

Sorry for opening the discussion, I don't see the explanation in doxygen.