memcached RSS never drops after evictions: slab allocator holds freed pages
Observed behavior On memcached 1.6.x running with the default slab allocator, resident memory climbs as slab classes grow to accommodate peak item sizes, but after large-scale eviction or expiration the process RSS stays at its high-water mark. The bytes stat from stats falls as expected, yet the OS-visible memory footprint does not. This is distinct from th