[PATCH v6 7/7] mm/memory_hotplug: Factor out altmap freeing checks

Andrew Morton akpm at linux-foundation.org
Fri Apr 24 20:20:39 AEST 2026


On Fri, 24 Apr 2026 09:34:43 +0200 "David Hildenbrand (Arm)" <david at kernel.org> wrote:

> On 4/24/26 04:55, Muchun Song wrote:
> > Use a small helper to centralize altmap freeing after verifying that all
> > vmemmap pages were released. This keeps the check consistent between the
> > normal teardown path and the memory hotplug error paths.
> > 
> > Suggested-by: David Hildenbrand (Arm) <david at kernel.org>
> > Signed-off-by: Muchun Song <songmuchun at bytedance.com>
> > ---
> 
> Thanks!
> 
> Acked-by: David Hildenbrand (Arm) <david at kernel.org>
> 
> Andrew usually prefers sending non-fixes separately,

Patches which are destined for the current -rc cycle (and possibly
-stable) (aka "hotfixes") take a different route into mainline from
regular next-merge-window material.  They go into different branches
and they have different timing.

If a patchset has a mixture of hotfixes (upstream next week) and
regular patches (upstream mid June) then I have to pull the series
apart, stage some things into one branch and other things in another
branch, rework the cover letter etc etc.  Problems with this are:

- what goes upstream doesn't map well onto what was presented on the
  mailing list.

- the hotfixes (upstream next week) may have dependencies on the
  regular patches (upstream mid June).  This is backwards.

Much depends on the urgency of the hotfixes.

In this case, iirc, the determination is "not very urgent at all".  So
the series is OK as-is - it's all "upstream mid June".

This is still a bit suboptimal because when the -stable maintainers get
onto backporting the cc:stable patches (after mid June), they may
encounter merge/build/runtime issues due to the absence of the
non-hotfix patches from this series.

So generally, it is best for authors to have a think about these
timing/priority issues and to present the patches in a suitable fashion
- hotfixes/-stable patches in one series then non-hotfixes in a second,
later series.  This way their presentation matches what goes upstream
and we reduce the possibility of problems when the -stable maintainers
get onto backporting.




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