Re: Moving ndctl development into the kernel tree?

[Chris Mason]

On 07/22/2017 02:49 PM, Dan Williams wrote:
> On Fri, Jul 21, 2017 at 7:52 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> > [ adding Chris ]
> >
> > On Fri, Jul 21, 2017 at 4:44 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> > > On Fri, Jul 21, 2017 at 3:58 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> > > > * Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> > > >
> > > > > [...]
> > > > >
> > > > > * Like perf, ndctl borrows the sub-command architecture and option
> > > > > parsing from git. So, this code could be refactored into something
> > > > > shared / generic, i.e. the bits in tools/perf/util/.
> > > >
> > > > Just as a side note, stacktool (tools/stacktool/) is using the Git sub-command and
> > > > options parsing code as well, and it's already sharing it with perf, via the
> > > > tools/lib/subcmd/ library.
> > > >
> > > > ndctl could use that as well.
> > >
> > > Ah, nice, that refactoring happened about a year after ndctl was born.
> > > Which brings up the next question about what to do with the git
> > > history, but I'd want to know if ndctl is even welcome upstream before
> > > digging any deeper.
> >
> > I suspect this would be similar to what Chris did to merge btrfs while
> > retaining the standalone history. Chris, any pointers on what worked
> > well and what if anything you would do differently? I.e. I'm looking
> > to use git filter-branch to rewrite ndctl history as if if had always
> > been in tools/ndctl in the kernel tree. I found this old thread
> > https://lkml.org/lkml/2008/10/30/523 and it seems to also recommend
> > using an older kernel as the branch base.
>
> So it wasn't as painful as I thought it would be, I just used the
> script Linus recommended in that thread. Here is what I came up with
> merging the last ndctl release on top of v4.9, and then applying the
> pending development patches re-filtered to tools/ndctl:
>
>      https://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm.git/log/?h=for-4.14/ndctl
>
> ...the next thing would be to rework the versioning to use the kernel
> version and switch to using tools/lib/subcmd/.

I'd like to say I figured it all out back then, but the truth is that 
Linus held my hand the whole way.  My memory of it is that his script 
worked really well, I just ran that and verified the results.

-chris