default or selected kernelversion does not have config value CONFIG_SLAB.
Result is shown for kernelversion 6.9.9

SLAB

modulename: slab.ko

configname: CONFIG_SLAB

Choose SLAB allocator
└─>SLAB
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
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.

source code: