== DF-5736 baseline run: $(date) ==
guest: DragonFly 6.5-DEVELOPMENT X86_64_GENERIC
trigger: sysctl hw.hcih_fire_memo=1  (each = 64 InquiryResult + 64 RssiResult events,
        16 unique bdaddrs per event = 2048 unique responses per fire)

$ sysctl hw.hcih_fire_memo=1
[harness] memos before: 0
[harness] memos after: 1436 (allocated 1436 for 2048 responses, none reclaimed: expiry reaps only on hci_memo_find)

$ sysctl hw.hcih_fire_memo=1   (x2 more)
[harness] memos before: 1436
[harness] memos after: 2848 (allocated 1412 for 2048 responses, ...)
[harness] memos before: 2848
[harness] memos after: 3184 (allocated 336 for 2048 responses, ...)

$ vmstat -m | grep -i bluetooth
          Bluetooth   3.11K    150K       0    390M    3.11K

=> monotonic unbounded growth; nothing reclaimed; ~612/2048 responses were
   dropped by the production hci_eventq_max=20 backpressure (rate limiter only).