Time to increase MAX_TASKS?

[Sean Bruno]

The new Dell machines are doing a lot more of outstanding ACPI "things"
currently.  So much in fact, that they are exceeding ACPI_MAX_TASKS and
are throwing errors indicating thing:

<snip>
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on
isa0
AcpiOsExecute: failed to enqueue task, consider increasing the
debug.acpi.max_tasks tunable
AcpiOsExecute: failed to enqueue task, consider increasing the
debug.acpi.max_tasks tunable
est0: <Enhanced SpeedStep Frequency Control> on cpu0
.....imecounters tick every 1.000 msec
smbios: System Management BIOS version 2.7
Profiling kernel, textsize=6861200 [ffffffff8029b190..ffffffff80926320]
usbus0: 480Mbps High Speed USB v2.0
usbus1: 480Mbps High Speed USB v2.0
ugen0.1: <Intel> at usbus0
uhub0: <Intel EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus0
ugen1.1: <Intel> at usbus1
uhub1: <Intel EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus1
ipmi0: IPMI device rev. 1, firmware rev. 1.10, version 2.0
ipmi0: Number of channels 6
ipmi0: Attached watchdog
AcpiOsExecute: failed to enqueue task, consider increasing the
debug.acpi.max_tasks tunable
mfid0 on mfi0
</snip>

the current value in sys/dev/acpica/acpivar.h of 32 is no longer
sufficient on the r420/r320 Sandybridge class of box.  

I am currently running with a value of 128 and doing a bit of testing.

Sean