Re: [PATCH 01/10] doc: Move SLUB documentation to the admin guide

Vlastimil Babka
2025-06-09T12:13:11Z

On 6/7/25 00:22, Matthew Wilcox (Oracle) wrote:
> This section is supposed to be for internal documentation, while the
> document is advice for sysadmins. Move it to the appropriate place.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Makes sense.

> --- a/Documentation/mm/slub.rst
> +++ b/Documentation/admin-guide/mm/slab.rst
> @@ -1,10 +1,8 @@
> ==========================
> -Short users guide for SLUB
> +Short users guide for SLAB

Agreed with Harry. We could say "for the slab allocator".
Ideally all SLUB references in user-facing text would be removed at some
point, but we can get there later.

> ==========================
>
> -The basic philosophy of SLUB is very different from SLAB. SLAB
> -requires rebuilding the kernel to activate debug options for all
> -slab caches. SLUB always includes full debugging but it is off by default.
> +SLUB always includes full debugging but it is off by default.

How about:

The slab allocator includes full debugging support (when built with
CONFIG_SLUB_DEBUG=y) but it is off by default (unless built with
CONFIG_SLUB_DEBUG_ON=y).

> SLUB can enable debugging only for selected slabs in order to avoid
> an impact on overall system performance which may make a bug more
> difficult to find.
> diff --git a/Documentation/mm/index.rst b/Documentation/mm/index.rst
> index d3ada3e45e10..fb45acba16ac 100644
> --- a/Documentation/mm/index.rst
> +++ b/Documentation/mm/index.rst
> @@ -56,7 +56,6 @@ documentation, or deleted if it has served its purpose.
> page_owner
> page_table_check
> remap_file_pages
> - slub
> split_page_table_lock
> transhuge
> unevictable-lru