Re: [dpdk-dev] [PATCH v2 3/4] common_base: extend RTE_MAX_ETHPORTS from 32 to 1024

["Yang, Zhiyong" <zhiyong.yang@intel.com>]

Hi, konstantin:

> > > It should be possible to have a dynamically allocated ethdev array,
> > > which would allow use to have a default value - which could be e.g.
> > > 32 or 64 as now - while also allowing a run-time parameter to increase that
> to thousands if needed.
> > >
> > > /Bruce
> >
> > In testpmd,  the following function will be called to validate the port_id.
> > So, It is necessary to modify the max port num RTE_MAX_ETHPORTS.
> 
> There are quite a lot memory allocations (both static an dynamic) inside DPDK
> libs and sample apps  that use RTE_MAX_ETHPORTS.
> Increasing RTE_MAX_ETHPORTS would increase DPDK memory requirements
> quite significantly.
> Why do you think it is *necessary* to increase default RTE_MAX_ETHPORTS to
> 1024?
> Konstantin

One reason is that some users have the requirement of more than 32 ports now.
But it need to reconfigure and recompile dpdk. 
Another reason is that validating team doesn't modify the common_base when
doing regression test. But they need to validate if uint16_t port_id can work.

Bruce suggests to pass parameter and dynamically allocate ethdev array at run time.
It is another method. I'm thinking about it. 

Thanks
Zhiyong