[$] SLOB nears the end of the road

The kernel project tries hard to avoid duplicating functionality within itscode base; whenever possible, a single subsystem is made to serve all usecases. There is one notable exception to this rule, though: there arethree object-level memory allocators ("slab allocators") in the kernel.The desire to reduce the count has been growing stronger over the years,and some steps have been taken in 6.2 to eliminate the least-lovedallocator - SLOB - in the relatively near future.