Re: [PATCH v1 0/5] MM_CID and HPCC mm_struct static init fixes

[Andrew Morton]

On Sun, 21 Dec 2025 18:29:21 -0500 Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> Mark Brown reported a regression [1] on linux next due to the
> hierarchical percpu counters (HPCC). You mentioned they were only in
> mm-new (and therefore not pulled into -next) [2], but it looks like they
> got more exposure that we expected. :)

We try to please ;)

Mark's report is why this series remains in mm-new and didn't get
promoted to mm-unstable (and hence linux-next).

Also, I anticipate a new version of this series thanks to
https://lkml.kernel.org/r/2fb78e41-5e56-425f-925f-a29524355d2c@xxxxxxxxxxxx

> This bug hunting got me to fix static initialization issues in both
> MM_CID (for upstream) and HPCC (mm-new). Mark tested my series and
> confirmed that it fixes his issues.
> 
> Please consider the HPCC fixes for mm-new, and the MM_CID fixes for
> upstream.
> 
> This series is based on mm-new
> commit 287373d0b6ee ("selftests/mm: fix comment for check_test_requirements")

Well, simply appending this series to your "mm: Fix OOM killer
inaccuracy on large many-core systems, v10" will create an annoying
bisection hole.

Also, there are some cc:stable fixes in here which depend upon the
presence of "mm: Fix OOM killer inaccuracy on large many-core systems"
series, which is all backwards.


So for now I'll toss this series in there for testing but I'll ask for
a redo, please.

- All cc:stable patches prepared in a standalone fashion against
  latest mainline.

- Any non-cc:stable patches which fix things in current mm-new come
  next.  Perhaps view these as preparation for "mm: Fix OOM killer
  inaccuracy on large many-core systems".

- Then "mm: Fix OOM killer inaccuracy on large many-core systems,
  v11" which incorporates anything which didn't make it into the above
  two categories.

That could be as many as three patch series. Thanks.