Re: [dpdk-dev] [PATCH 00/39] adding eventmode helper library

[Jerin Jacob Kollanukkaran <jerinj@marvell.com>]

> -----Original Message-----
> From: Anoob Joseph
> Sent: Thursday, June 27, 2019 10:58 AM
> To: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Mattias Rönnblom
> <mattias.ronnblom@ericsson.com>; Nikhil Rao <nikhil.rao@intel.com>; Erik
> Gabriel Carrillo <erik.g.carrillo@intel.com>; Abhinandan Gujjar
> <abhinandan.gujjar@intel.com>; Bruce Richardson
> <bruce.richardson@intel.com>; Pablo de Lara
> <pablo.de.lara.guarch@intel.com>
> Cc: Narayana Prasad Raju Athreya <pathreya@marvell.com>; dev@dpdk.org;
> Lukas Bartosik <lbartosik@marvell.com>; Pavan Nikhilesh Bhagavatula
> <pbhagavatula@marvell.com>; Hemant Agrawal
> <hemant.agrawal@nxp.com>; Nipun Gupta <nipun.gupta@nxp.com>; Harry
> van Haaren <harry.van.haaren@intel.com>; Liang Ma
> <liang.j.ma@intel.com>
> Subject: RE: [dpdk-dev] Re: [PATCH 00/39] adding eventmode helper library
> 
> Hi Jerin, Mattias,
> 
> Please see inline.
> 
> Thanks,
> Anoob
> 
> > -----Original Message-----
> > From: Jerin Jacob Kollanukkaran
> > Sent: Tuesday, June 25, 2019 4:03 PM
> > To: Anoob Joseph <anoobj@marvell.com>; Mattias Rönnblom
> > <mattias.ronnblom@ericsson.com>; Nikhil Rao <nikhil.rao@intel.com>;
> > Erik Gabriel Carrillo <erik.g.carrillo@intel.com>; Abhinandan Gujjar
> > <abhinandan.gujjar@intel.com>; Bruce Richardson
> > <bruce.richardson@intel.com>; Pablo de Lara
> > <pablo.de.lara.guarch@intel.com>
> > Cc: Narayana Prasad Raju Athreya <pathreya@marvell.com>;
> dev@dpdk.org;
> > Lukas Bartosik <lbartosik@marvell.com>; Pavan Nikhilesh Bhagavatula
> > <pbhagavatula@marvell.com>; Hemant Agrawal
> <hemant.agrawal@nxp.com>;
> > Nipun Gupta <nipun.gupta@nxp.com>; Harry van Haaren
> > <harry.van.haaren@intel.com>; Liang Ma <liang.j.ma@intel.com>
> > Subject: RE: [dpdk-dev] Re: [PATCH 00/39] adding eventmode helper
> > library
> >
> > > -----Original Message-----
> > > From: Anoob Joseph
> > > Sent: Thursday, June 20, 2019 9:15 AM
> > > To: Mattias Rönnblom <mattias.ronnblom@ericsson.com>; Jerin Jacob
> > > Kollanukkaran <jerinj@marvell.com>; Nikhil Rao
> > > <nikhil.rao@intel.com>; Erik Gabriel Carrillo
> > > <erik.g.carrillo@intel.com>; Abhinandan Gujjar
> > > <abhinandan.gujjar@intel.com>; Bruce Richardson
> > > <bruce.richardson@intel.com>; Pablo de Lara
> > > <pablo.de.lara.guarch@intel.com>
> > > Cc: Narayana Prasad Raju Athreya <pathreya@marvell.com>;
> > dev@dpdk.org;
> > > Lukas Bartosik <lbartosik@marvell.com>; Pavan Nikhilesh Bhagavatula
> > > <pbhagavatula@marvell.com>; Hemant Agrawal
> > <hemant.agrawal@nxp.com>;
> > > Nipun Gupta <nipun.gupta@nxp.com>; Harry van Haaren
> > > <harry.van.haaren@intel.com>; Liang Ma <liang.j.ma@intel.com>
> > > Subject: RE: [dpdk-dev] [EXT] Re: [PATCH 00/39] adding eventmode
> > > helper library
> > > > However, the flexibility and many of the parameters are there for
> > > > a reason (those there aren't should be deprecated). I would expect
> > > > a real-world application to tweak quite a few of them. I know our
> > > > applications
> > > do.
> > > >
> > > > I worry I have is that if you put eventmode (in its current form)
> > > > forward as a generic framework, applications might start using it,
> > > > only to realize it's not flexible enough, and then eventmode is
> > > > just an extra layer, increasing rather than reducing complexity.
> > > > Or even worse, the application's developers are forced to do a
> > > > big-bang switch over to using the event and ethernet device APIs
> > > > directly, in case they can't patch DPDK to work around the
> > > > eventmode-
> > > > assumption-that-
> > > didn't-hold-for-them.
> > > >
> > > > You could always add flexibility to the framework (as you
> > > > encounter a need for it), but then it will grow in complexity as well.
> > > >
> > > > A less ambitious approach would be to instead do a properly
> > > > modularized, non-trivial eventdev example application, for the
> > > > applications to start off from, instead of a generic library.
> > > >
> > > > I would expect it to be very difficult to design a truly generic
> > > > application framework for eventdev-based applications. Such a
> > > > framework would tie everything that's needed in a non-trivial
> > > > application together. If successful, it would be a huge step
> > > > toward making DPDK an operating system for packet processing
> applications.
> > >
> > > [Anoob] The idea here is not to deprecate any event dev APIs. I do
> > > agree that all the configuration exposed by eventdev & adapters are
> > > required for various requirements in the real world applications.
> > > But the requirement to understand & use all this configuration is
> > > making the applications complicated and causes significant effort
> > > from anyone who
> > would want to get started with event mode.
> > > The idea of helper is to allow an easy framework for applications to
> > > get started with eventmode, and then use various options from C/L or
> > > config file (both
> > > planned) to override the configuration as required. DPDK has
> > > components like crypto-scheduler which abstracts lot of
> > > configuration and simplify usage from application's perspective.
> > > This effort is on similar
> > lines.
> > >
> > > My patchset is a followup to http://patches.dpdk.org/patch/37955 ,
> > > wherein the approach of introducing a helper library for event mode
> > > was mooted. The initial patch proposed additions in one application,
> > > and that involved huge code additions just for doing the configuration.
> > >
> > > The helper library will be experimental while we add event-mode
> > > support for other applications like l3fwd & ipsec-secgw. I expect
> > > the helper library to be complete over the course of those
> > > applications also
> > using the helper library.
> >
> >
> > I have only concern about moving this as library inside eventdev that
> > till we have mature version of helper library the eventdev library ABI
> > will not stable(i.e .so file version needs to be incremented as when a
> > change needed). Which align with Mattias thoughts for some other
> > reason:. How about moving this code to
> > 1) example/common or
> > 2) to specific application itself, once at least two applications
> > starts using it then move to Eventdev library.
> >
> > Thoughts?
> 
> [Anoob] Either location is not a problem if there is a consensus. Earlier the
> suggestion was to move it to library (when the patch was submitted with
> changes added in app).


If there NO objections then lets move to example/common.

Cc: techboard@dpdk.org for final decision on the location.





> 
> Since there are other comments, which are being addressed, I would like to
> send the next series with the current layout itself. And when we have an
> agreement on the location to be used, I'll make the changes. Is that fine?
> 
> >
> >
> >
> >
> > >
> > > >
> > > > What event devices have you tested with?
> > >
> > > [Anoob] Eventmode helper is tested with the following combinations,
> > >     1. event-octeontx event PMD & nicvf eth PMD
> > >     2. event-octeontx event PMD & eth-octeontx eth PMD