Re: [PATCH v2] mm/memory_hotplug: maintain N_NORMAL_MEMORY during hotplug

Andrew Morton
2026-03-30T21:46:41Z

On Mon, 30 Mar 2026 17:34:21 +0800 Hao Li <hao.li@linux.dev> wrote:

> > > Current users that benefit include list_lru, zswap, nfsd filecache,
> > > hugetlb_cgroup, and has_normal_memory sysfs reporting.
> > >
> > > Fixes: 8d2882a8edb8 ("mm,memory_hotplug: remove status_change_nid_normal and update documentation")
> >
> > The Fixes: tag indeed looks correct to me.
> >
> > By the way, MM needs an explicit Cc: stable@vger.kernel.org for backporting.
> >
> > Since this commit was introduced in v6.17 and we have v6.18 as LTS,
> > this should to be backported to v6.18.
>
> I had gone back and forth on whether to add the Cc tag, but I'm happy to
> include it now!

That's OK, I'm very cc:stable-vigilant. Thanks, I'll get this upstreamed during
this -rc cycle.

I do like our cc:stable patches to include a clear description of the
userspace-visible impacts of the bug. Two reasons:

- To explain to -stable maintainers why we're requesting the
backport. If they care. Heck, and to explain to me why I'm doing
this!

- To help out someone who is using an older kernel (there are many)
who is dealing with a bug report. They're looking at this changelog
thinking "hm, I wonder if this patch will fix that bug". Let's add a
few words in there to help out with their pattern matching.

So, and not for the first time ;), what are the userspace-visible
runtime effects of this bug?