On Thu, Oct 17, 2019 at 6:56 PM David Christensen <d...@linux.vnet.ibm.com> wrote: > > >>>> 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. > >>> > >> If the code makes no difference anyway, should we just take it out so? > > > > +1 :-) > > I think there's a need for a larger review of Power8 vs. Power9 support. > You currently need to specify Power8 as the DPDK build target (e.g. > ppc_64-power8-linux-gcc) but all of our internal development and testing > efforts are targeting Power9 systems. My preference would be to drop > Power8 support all together but I'm reluctant to make such a potentially > large change so close to an LTS release target, and not without > soliciting some community comment on the idea. As a result, I'd prefer > to keep the change "as is" for this release.
Ok, I will take it as is, but please do investigate this. The lesser special cases like these, the better. -- David Marchand
