Linux 6.4 Looking To Drop The SLOB Memory Allocator

A patch series is proposing that the SLOB memory allocator be removed from the Linux 6.4 kernel this summer.

Following kernel developer discussions last year, the Linux 6.2 kernel went ahead and deprecated SLOB as the simple allocator. The SLOB allocator was designed to be space efficient but ends up being not as scalable.

Kernel developers want to get rid of the SLOB code entirely as it's a maintenance pain and they want to make improvements to the SLUB allocator with having less code to worry about. Kernel developers are also planning to also deprecate and remove SLAB, leaving SLUB as the optimal memory allocator moving forward.

Vlastimil Babka of SUSE sent out a patch series that removes SLOB. As expressed in the patch cover letter, the hope is to get this vetted in the Linux "-next" branch and aim to remove it in the mainline Linux 6.4 kernel if there are no objections.

Clearing out SLOB lightens the kernel by nearly one thousand lines of code and already allows for making some immediate benefits too. See the patch series for more details on the likely removal of SLOB happening this summer.