Re: [PATCH] docs: Add overview and SLUB allocator sections to slab documentation

Matthew Wilcox
2026-04-18T05:04:46Z

On Sat, Apr 18, 2026 at 12:06:19AM +0000, Nick Huang wrote:
> - Add "Overview" section explaining the slab allocator's role and purpose
> - Document the three main slab allocator implementations (SLAB, SLUB, SLOB)

Umm.

commit 6630e950d532
Author: Vlastimil Babka <vbabka@kernel.org>
Date: Tue Feb 28 15:38:07 2023 +0100

mm/slob: remove slob.c

commit 16a1d968358a
Author: Vlastimil Babka <vbabka@kernel.org>
Date: Mon Oct 2 20:43:43 2023 +0200

mm/slab: remove mm/slab.c and slab_def.h

Care to revise?

> - Highlight SLUB as the default allocator on modern systems
> - Add "SLUB Allocator" subsection with detailed information:
> - Explain SLUB's design goals and advantages over legacy SLAB
> - Document its focus on simplification and performance
> - Note support for both uniprocessor and SMP systems
>
> Signed-off-by: Nick Huang <sef1548@gmail.com>
> ---
> Documentation/mm/slab.rst | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/Documentation/mm/slab.rst b/Documentation/mm/slab.rst
> index 2bcc58ada302..2d1d093afb7b 100644
> --- a/Documentation/mm/slab.rst
> +++ b/Documentation/mm/slab.rst
> @@ -4,6 +4,32 @@
> Slab Allocation
> ===============
>
> +Overview
> +========
> +
> +The slab allocator is responsible for efficient allocation and reuse of
> +small kernel objects. It reduces internal fragmentation and improves
> +performance by caching frequently used objects.
> +
> +The Linux kernel provides multiple slab allocator implementations,
> +including SLAB, SLUB, and SLOB. Among these, SLUB is the default
> +allocator on most modern systems.
> +
> +SLUB Allocator
> +==============
> +
> +Overview
> +--------
> +
> +SLUB is a slab allocator designed to replace the legacy SLAB allocator
> +(mm/slab.c). It addresses the complexity, scalability limitations, and
> +memory overhead of the SLAB implementation.
> +
> +The primary goal of SLUB is to simplify slab allocation while improving
> +performance on both uniprocessor (UP) and symmetric multiprocessing (SMP)
> +systems.
> +
> +
> Functions and structures
> ========================
>
> --
> 2.43.0
>
>