KASSERT triggered in pcu_load()

[Alexander Nasonov <alnsn%yandex.ru@localhost>]

My aarch64 server had been running fine for a couple of weeks but
it all suddenly changed yesterday when it crashed about tree times.

I captured a screenshot of one crash:

panic: kernel diagnostic assertion "l->l_pcu_cpu[id] == NULL", ...
cpu7: Begin traceback...
trace fp ffffffc0a4ee7cc0
fp ffffffc0a4ee7cc0 vpanic() at ffffffc000408b68 netbsd:vpanic+0x190
fp ffffffc0a4ee7d40 kern_assert() at ffffffc000529c60 netbsd:kern_assert+0x58
fp ffffffc0a4ee7dd0 pcu_load() at ffffffc000401a2c netbsd:pcu_load +0x21c
fp ffffffc0a4ee7e70 trap_el0_sync() at ffffffc0000656d0 netbsd:trap_el0_sync+0x1d0
fp ffffffc0a4ee7ed0 el0_trap() at ffffffc00006330 netbsd:el0_trap

It's followed by registers dump (available upon request).

cpu6 was in sched_pstats, other cpus were idle.

-- 
Alex