Re: [PATCH bpf-next v5 01/34] mm: memcontrol: use helpers to read page's memcg data

[Alexei Starovoitov]

On Thu, Nov 12, 2020 at 7:18 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu, 12 Nov 2020 19:04:56 -0800 Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote:
>
> > On Thu, Nov 12, 2020 at 04:26:10PM -0800, Roman Gushchin wrote:
> > >
> > > These patches are not intended to be merged through the bpf tree.
> > > They are included into the patchset to make bpf selftests pass and for
> > > informational purposes.
> > > It's written in the cover letter.
> > ...
> > > Maybe I had to just list their titles in the cover letter. Idk what's
> > > the best option for such cross-subsystem dependencies.
> >
> > We had several situations in the past releases where dependent patches
> > were merged into multiple trees. For that to happen cleanly from git pov
> > one of the maintainers need to create a stable branch/tag and let other
> > maintainers pull that branch into different trees. This way the sha-s
> > stay the same and no conflicts arise during the merge window.
> > In this case sounds like the first 4 patches are in mm tree already.
> > Is there a branch/tag I can pull to get the first 4 into bpf-next?
>
> Not really, at present.  This is largely by design, although it does cause
> this problem once or twice a year.
>
> These four patches:
>
> mm-memcontrol-use-helpers-to-read-pages-memcg-data.patch
> mm-memcontrol-slab-use-helpers-to-access-slab-pages-memcg_data.patch
> mm-introduce-page-memcg-flags.patch
> mm-convert-page-kmemcg-type-to-a-page-memcg-flag.patch
>
> are sufficiently reviewed - please pull them into the bpf tree when
> convenient.  Once they hit linux-next, I'll drop the -mm copies and the
> bpf tree maintainers will then be responsible for whether & when they
> get upstream.

That's certainly an option if they don't depend on other patches in the mm tree.
Roman probably knows best ?