Re: [dpdk-dev] [PATCH v8 02/19] eal: enable multi process init callback

[Thomas Monjalon <thomas@monjalon.net>]

03/07/2018 17:16, Zhang, Qi Z:
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > 
> > Hi Qi,
> > 
> > Sorry I do not understand neither the commit log, nor the doxygen.
> > If it can help, consider your reader is in a bad mood and needs a pleasant
> > description.
> 
> OK, I think is not a grammar issue since it almost passed a grammar check :)
> 
> So more explanation: 
> Basically we need to register mp action callback in ethdev layer,

What is "mp action callback"?
Why do you need it in ethdev?

> but this should happens during rte_eal_init 

Why it should be done in rte_eal_init?

> ethdev don't have a general init function that can be invoked by eal
> during rte_eal_init, actually I guess, all no-eal module don't have 

What is "no-eal module"?

> in vdev bus, it register the mp action at the first bus scan happen.
> but in ethdev, we can't do that way, because, we don' t know
> when device will be attached or detached. 
> so we need that function to help register a callback function which will be invoked during rte_eal_init.
> 
> 
> > 
> > 02/07/2018 07:44, Qi Zhang:
> > > Introduce new API rte_eal_register_mp_init that help to register a
> > > callback function which will be invoked right after multi-process
> > > channel be established (rte_mp_channel_init). Typically the API will
> > > be used by other module that want it's mp channel action callbacks can
> > > be registered during rte_eal_init automatically.
> > [...]
> > > +/**
> > > + * @warning
> > > + * @b EXPERIMENTAL: this API may change without prior notice
> > > + *
> > > + * Register a callback function that will be invoked right after
> > > + * multi-process channel be established (rte_mp_channel_init).
> > > +Typically
> > > + * the function is used by other module that want it's mp channel
> > > + * action callbacks can be registered during rte_eal_init automatically.
> > > + *
> > > + * @note
> > > + *   This function only take effect when be called before rte_eal_init,
> > > + *   and all registered callback will be clear during rte_eal_cleanup.