[PATCH] mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED

[Hyeonggon Yoo]

On Tue, May 23, 2023 at 6:12 PM Vlastimil Babka <vbabka at suse.cz> wrote:
>
> As discussed at LSF/MM [1] [2] and with no objections raised there,
> deprecate the SLAB allocator. Rename the user-visible option so that
> users with CONFIG_SLAB=y get a new prompt with explanation during make
> oldconfig, while make olddefconfig will just switch to SLUB.
>
> In all defconfigs with CONFIG_SLAB=y remove the line so those also
> switch to SLUB. Regressions due to the switch should be reported to
> linux-mm and slab maintainers.
>
> [1] https://lore.kernel.org/all/4b9fc9c6-b48c-198f-5f80-811a44737e5f@suse.cz/
> [2] https://lwn.net/Articles/932201/
>
> Signed-off-by: Vlastimil Babka <vbabka at suse.cz>
> ---

<snip>

> diff --git a/mm/Kconfig b/mm/Kconfig
> index 7672a22647b4..b537c4436d18 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -218,11 +218,18 @@ choice
>         help
>            This option allows to select a slab allocator.
>
> -config SLAB
> -       bool "SLAB"
> +config SLAB_DEPRECATED
> +       bool "SLAB (DEPRECATED)"
>         depends on !PREEMPT_RT
>         select HAVE_HARDENED_USERCOPY_ALLOCATOR
>         help
> +         Deprecated and scheduled for removal in a few cycles. Replaced by
> +         SLUB.
> +
> +         If you cannot migrate to SLUB, please contact linux-mm at kvack.org
> +         and the people listed in the SLAB ALLOCATOR section of MAINTAINERS
> +         file, explaining why.
> +
>           The regular slab allocator that is established and known to work
>           well in all environments. It organizes cache hot objects in
>           per cpu and per node queues.
> @@ -240,6 +247,11 @@ config SLUB
>
>  endchoice
>
> +config SLAB
> +       bool
> +       default y
> +       depends on SLAB_DEPRECATED
> +
>  config SLUB_TINY
>         bool "Configure SLUB for minimal memory footprint"
>         depends on SLUB && EXPERT
> --
> 2.40.1

Thank you for the work!
It looks good to me.
let's see some users raise their voice.

Acked-by: Hyeonggon Yoo <42.hyeyoo at gmail.com>