[PATCH] mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED

[Vlastimil Babka]

On 5/24/23 02:29, David Rientjes wrote:
> On Tue, 23 May 2023, Vlastimil Babka 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>
> 
> Acked-by: David Rientjes <rientjes at google.com>

Thanks.

> The Kconfig option says that SLAB will be removed in a few cycles.  I 
> think we should wait until at least the next LTS kernel is forked at the 
> end of the year so that users who upgrade to only the LTS releases can be 
> prompted for this change and surface any concerns.  Slab allocation is a 
> critical subsystem, so I presume this is the safest and most responsible 
> way to do the SLAB deprecation.  Hopefully that timeline works for 
> everybody.

Sure, and in fact looking at predicted release dates [1], if the deprecation
goes into 6.5 then 6.7 ("few" == 2) is already end of January 2024, anyway.

[1] https://hansen.beer/~dave/phb/