Re: [RFCv2] service core concept

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

> -----Original Message-----
> From: Ananyev, Konstantin
> Sent: Saturday, June 3, 2017 11:23 AM
> To: Van Haaren, Harry <harry.van.haaren@intel.com>; dev@dpdk.org
> Cc: Thomas Monjalon <thomas@monjalon.net>; Jerin Jacob <jerin.jacob@caviumnetworks.com>;
> Richardson, Bruce <bruce.richardson@intel.com>; Wiles, Keith <keith.wiles@intel.com>
> Subject: RE: [dpdk-dev] [RFCv2] service core concept

<snip>

> > In particular this version of the API enables applications that are not aware of services to
> > benefit from the services concept, as EAL args can be used to setup services and service
> cores.
> > With this design, switching to/from SW/HW PMD is transparent to the application. An example
> > use-case is the Eventdev HW PMD to Eventdev SW PMD that requires a service core.
> >
> > I have noted the implementation comments that were raised on the v1. For v2, I think our
> time
> > is better spent looking at the API design, and I will handle implementation feedback in the
> > follow-up patchset to v2 RFC.
> >
> > Below a summary of what we are trying to achieve, and the current API design.
> > Have a good weekend! Cheers, -Harry
> 
>
> Looks good to me in general.
> The only comment I have - do we really need to put it into rte_eal_init()
> and a new EAL command-line parameter for it?
> Might be better to leave it to the particular app to decide.


There are a number of options here, each with its own merit:

A) Services/cores config in EAL
Benefit is that service functionality can be transparent to the application. Negative is that the complexity is in EAL.

B) Application configures services/cores
Benefit is no added EAL complexity. Negative is that application code has to configure cores (duplicated per application).


To answer this question, I think we need to estimate how many applications would benefit from EAL integration and balance that against the "complexity cost" of doing so. I do like the simplicity of option (B), however if there is significant value in total transparency to the application I think (A) is the better choice.


Input on A) or B) welcomed! -Harry