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

From: Andrew Morton
Date: Thu Nov 12 2020 - 22:18:32 EST


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.