Last time I checked (and it's been a while), it did reduce _internal fragmentation_ for the naive "memory used after boot" scenario. I don't think I ever advertised it as a performance improvement. Dunno if somebody else did.In my not-so-humble opinion, either the merging needs to go awayCache merging may have been advertised as a bigger performance improvement
entirely, or the misleading output needs to be fixed.
than it actually is, and I don't do it in my own slab allocator for other
reasons, but it does lead to more effective memory use by reducing slab
fragmentation. On one of my benchmarking servers, over 60% of caches are
merged and /sys/kernel/slab/.../partial reports roughly the same percent
of fewer total partial slabs over the system in comparison to
slub_nomerge.