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.
Dave
