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

[David Marchand <david.marchand@redhat.com>]

On Thu, Oct 17, 2019 at 6:18 PM Burakov, Anatoly
<anatoly.burakov@intel.com> wrote:
>
> 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?

+1 :-)


-- 
David Marchand