RE: Copy-pasted code should be updated

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

<snip>
> >
> > >
> > > Dear Intel PMD maintainers (CC: techboard),
> > >
> > > I strongly recommend that you update the code you copy-pasted from
> > the
> > > mempool library to your PMDs, so they reflect the new and improved
> > > mempool cache behavior [1]. When choosing to copy-paste code from a
> > core
> > > library, you should feel obliged to keep your copied code matching
> > the source
> > > code you copied it from!
> > >
> > > Also, as reported in bug #1052, you forgot to copy-paste the
> > instrumentation,
> > > thereby 1. making the mempool debug statistics invalid and 2.
> > omitting the
> > > mempool accesses from the trace when using your PMDs. :-(
> > We are working on mempool APIs to expose the per core cache memory to
> > PMD so that the buffers can be copied directly. We are planning to fix
> > this duplication as part of that.
> 
> Is the copy-paste bug fix going to make it for 22.11?
It will not make it to 22.11. It is targeted for 23.02.

> 
> Otherwise, these PMDs are managing the mempool cache differently than
> the mempool library does. (And the mempool library instrumentation will
> remain partially bypassed for these PMDs.) This should be mentioned as a
> know bug in the release notes.
Agree

> 
> >
> > >
> > > Alternatively, just remove the copy-pasted code and use the mempool
> > > library's API instead. ;-)
> > >
> > > The direct re-arm code also contains copy-pasted mempool cache
> > handling
> > > code - which was accepted with the argument that the same code was
> > > already copy-pasted elsewhere. I don't know if the direct re-arm
> > > code
> > also
> > > needs updating... Authors of that patch (CC to this email), please
> > coordinate
> > > with the PMD maintainers.
> > Direct-rearm patch is not accepted yet.
> >
> > >
> > > PS:  As noted in the 22.11-rc1 release notes, more changes to the
> > mempool
> > > library [2] may be coming.
> > >
> > > [1]:
> > >
> https://patches.dpdk.org/project/dpdk/patch/20221007104450.2567961-1
> > > -
> > > andrew.rybchenko@oktetlabs.ru/
> > >
> > > [2]: https://patches.dpdk.org/project/dpdk/list/?series=25063
> > >
> > > -Morten
> >