Re: [PATCH] Docs/mm: document Boot Memory

Mike Rapoport
2026-03-16T06:47:28Z

On Sun, Mar 15, 2026 at 08:43:24PM +0000, Lorenzo Stoakes (Oracle) wrote:
> NAK for being AI slop, again, obviously.
>
> +cc Mike, the 'boot memory' maintainer, who again I'm sure will be
> overjoyed by this.

I'm not going to review it thoroughly because
"maintainers are entitled to reject your series without detailed review"

> Reasons, as the rest:
> - Worthless documentation
> - Everything about patch screams 'zero effort, Claude did it all'
> - Bad etiquette
>
> On Sat, Mar 14, 2026 at 04:25:27PM +0100, Kit Dallege wrote:
> > Fill in the bootmem.rst stub created in commit 481cc97349d6
> > ("mm,doc: Add new documentation structure") as part of
> > the structured memory management documentation following
> > Mel Gorman's book outline.

We don't need to fill in missing parts just to fill files with contents, we
need quality documentation.
This doc does not improve over what we already have in
Documentation/core-api/boot-time-mm.rst.

...

> > +The memblock allocator fills this role, managing physical memory from the
> > +earliest stages of boot until the buddy allocator takes over. The
> > +implementation is in ``mm/memblock.c`` and ``mm/mm_init.c``.
>
> This is at least reasonable.

But still wrong. mm_init.c is not a part of memblock allocator.

> > +- ``kernelcore=`` sets the amount of memory that must be in non-movable
> > + zones.
> > +- ``movablecore=`` sets the amount of memory to place in ``ZONE_MOVABLE``.
> > +- ``movable_node`` allows entire NUMA nodes to be treated as movable.
> > +- ``kernelcore=mirror`` restricts non-movable memory to mirrored regions.
> > +
> > +These parameters control the boundary between ``ZONE_MOVABLE`` and the
> > +other zones, which in turn affects how much memory is available for
> > +transparent huge pages, memory hot-remove, and CMA.

Oh, my ...
How CMA and THP are related to ZONE_MOVABLE here?!

--
Sincerely yours,
Mike.