On Tue, Mar 14, 2023 at 09:05:13AM +0100, Vlastimil Babka wrote: > As you're probably aware, my plan is to get rid of SLOB and SLAB, leaving > only SLUB going forward. The removal of SLOB seems to be going well, there > were no objections to the deprecation and I've posted v1 of the removal > itself [1] so it could be in -next soon. > > The immediate benefit of that is that we can allow kfree() (and kfree_rcu()) > to free objects from kmem_cache_alloc() - something that IIRC at least xfs > people wanted in the past, and SLOB was incompatible with that. > > For SLAB removal I haven't yet heard any objections (but also didn't > deprecate it yet) but if there are any users due to particular workloads > doing better with SLAB than SLUB, we can discuss why those would regress and > what can be done about that in SLUB. > > Once we have just one slab allocator in the kernel, we can take a closer > look at what the users are missing from it that forces them to create own > allocators (e.g. BPF), and could be considered to be added as a generic > implementation to SLUB. I guess eventually we want to merge the percpu allocator too.