HEADS-UP: ACPICA updated (again)

[Jukka Ruohonen <jruohonen%iki.fi@localhost>]

Hello.

I have just updated ACPICA to the latest and greatest. There has again been
some sweeping changes, so please send-pr(1) if you observe any regressions.

More specifically, big changes have occured in the interrupt handling and
its relation to acpiec(4). I take this opportunity to note some sysctl(8)
variables that have been added:

        $ sysctl hw.acpi.stat
        hw.acpi.stat.gpe = 20541
        hw.acpi.stat.sci = 20541
        hw.acpi.stat.fixed = 0
        hw.acpi.stat.method = 3963

* If a system experiences ACPI-related "interrupt storms", this should be
  seen in the 'hw.acpi.stat.sci' counter. It measures the amount of
  so-called SCI interrupts.

* On the other hand, if there would be a problem in dispatching the
  interrupts, there should be a relatively big difference between
  'hw.acpi.stat.sci' and 'hw.acpi.stat.gpe'.

* If there are problems in the generation of interrupts and ACPI events,
  neither counter should increase when for instance the AC adapter is
  disconnected, etc.

* Finally, some extraordinarily large changes in 'hw.acpi.stat.method'
  probably indicate some problems as well.

- Jukka.