Re: [dpdk-dev] [PATCH] eal:ppc: fix incorrect ifdef for ppc_64

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 16-Oct-19 9:45 PM, David Christensen wrote:
>>> An ifdef present in eal_memory.c references "RTE_ARCH_PPC64" when
>>> it should actually use "RTE_ARCH_PPC_64".  Simple testing revealed
>>> that both the PPC_64 and non-PPC_64 versions of the code involved
>>> work, but the PPC_64 version of the code is retained to be
>>> consistent with other instances in the same file where mmapped
>>> memory is accessed in reverse order on Power platforms.
>>
>> The change itself is not that scary, but just reading this commitlog I
>> fail to see the impact for an application.
>> Can you share some light?
>>
> 
> As far as I can tell there is no impact on any applications.  The old 
> code, which walked through the list in a forward direction, worked 
> perfectly well with testpmd and DPDK pktgen applications on Power systems.
> 
> With the ifdef fixed, the core walks the list in the reverse direction 
> as intended, the code still worked (i.e. no errors or problems were 
> observed in the same test applications).
> 
> I'm not completely familiar with why memseg lists must be traversed in 
> the reverse direction for Power systems.  It might be something specific 
> to Power 8 systems which I'm not actually supporting on DPDK, only the 
> Power 9 systems that I use for for development and testing.
> 
> Dave
> 

If the code makes no difference anyway, should we just take it out so?

-- 
Thanks,
Anatoly