I didn't think zaptel was supposed to have anything in /proc/interrupts unless I had actual zaptel hardware (I don't), which is why I'm using ztdummy.
dmesg snip
Zapata Telephony Interface Registered on major 196
Zaptel Version: 1.2.10 Echo Canceller: KB1
VPS: 109: started
loop: loaded (max 8 devices)
VPS: 112: started
Registered tone zone 0 (United States / North America)
UBC: BUG: fixing bad page PBs for c1646fbc
flags: 0x20000070 mapping: ef9c43fd mapcount: 0 count: 1
PB is c2e56da0 magic 1651769345
[<c015f2ab>] pb_remove_ref+0x34b/0x460
[<c016b380>] find_get_page+0x50/0x130
[<c018133a>] zap_pte_range+0x18a/0x2e0
[<c015ec88>] pb_add_ref+0x1f8/0x4d0
[<c0181513>] zap_pmd_range+0x83/0xb0
[<c01816bf>] unmap_page_range+0x5f/0xf0
[<c0181870>] unmap_vmas+0x120/0x200
[<c0189105>] exit_mmap+0xa5/0x260
[<c012d0ce>] mmput+0x7e/0x130
[<c01356ee>] do_exit+0x1be/0x860
[<c0135ece>] do_group_exit+0xbe/0x1d0
[<c0120c40>] do_page_fault+0x0/0x5dd
[<c057b61f>] syscall_call+0x7/0xb
Leak PB c2e56da0 for UB f6af0580
removed 1 PBs from hash
VPS: 112: stopped
VPS: 112: started
Registered tone zone 0 (United States / North America)
[root@sakura ~]# cat /proc/interrupts
CPU0
0: 147306633 IO-APIC-edge timer
8: 1 IO-APIC-edge rtc
9: 0 IO-APIC-level acpi
14: 454483 IO-APIC-edge ide0
16: 0 IO-APIC-level uhci_hcd
17: 0 IO-APIC-level uhci_hcd
18: 0 IO-APIC-level uhci_hcd
19: 0 IO-APIC-level ehci_hcd
21: 3515053 IO-APIC-level eth0
NMI: 147306628
LOC: 147310762
ERR: 0
MIS: 0