[dpdk-dev] [PATCH 1/2] eventdev: add event adapter for ethernet Rx queues

[Eads, Gage]

<snip>

> > >
> > > 5) specifying rte_event_eth_rx_adapter_conf.rx_event_port_id on
> > > rte_event_eth_rx_adapter_create() would waste one HW eventdev port
> > > if its happen to be used RX_ADAPTER_CAP_INBUILT_PORT on
> rte_event_eth_rx_adapter_queue_add().
> > > unlike SW eventdev port, HW eventdev ports are costly so I think, We
> > > need to have another eventdev PMD ops to create service/producer ports.
> > > Or any other scheme that creates
> > > rte_event_eth_rx_adapter_conf.rx_event_port_id
> > > on demand by common code.
> > >
> >
> > One solution is:
> >
> > struct rte_event_eth_rx_adapter_conf {
> >     uint8_t dev_id;
> >
> >     int (*conf_cb)(uint8_t id, uint8_t port_id, uint32_t flags, struct
> > rte_event_eth_rx_adapter_conf *conf);
> >
> >     unsigned int max_nb_rx;
> >
> >     int event_port_id;
> >
> >     char service_name[];
> > }
> >
> > Where dev_id and conf_cb have to be specified in the create call, but
> > event_port_id and service_name will be filled in when conf_cb() is
> > invoked
> 
> I was thinking like event_port_id will be rte_event_port_count() + 1.
> ie When adapter needs the additional port, It can
> - stop the eventdev
> - reconfigure with rte_event_queue_count() , rte_event_port_count() + 1
> - start the eventdev.
> 
> The only problem with callback is that all the application needs to implement it.
> If you think, application need more control then we can expose callback and if it
> is NULL then default handler can be called in common code.
> 

I don't think we can rely on there being another port available -- a user may have configured the sw eventdev with all 64 ports, for instance. What if the user is required to calculate cfg.nb_event_ports as a function of the RX_ADAPTER_CAP_INBUILT_PORT capability (i.e. add a port if the capability is not set), such that a reconfigure is not required?

As for application control: that would be a useful option in the conf_cb scheme. Some apps will want to configure the adapter's port (its new_event_threshold, its queue depths) differently from the default.

Thanks,
Gage