This patch enables multi-threaded execution of ACPI control methods.
Certain machines (e.g. the HP nx6125) require the concurrent execution
of several ACPI control methods. Without multithreading, processing
of ACPI events will be blocked, causing the machine to overheat and
possible damage.
This patch enables, optionally, the multithreaded execution of control
methods and fixes http://bugzilla.kernel.org/show_bug.cgi?id=5534.
The required code is compiled into the kernel unconditionally (whenever
ACPI is enabled in the kernel config). However, it is only activated
by the boot option acpi_pool_size=<positive integer> or echoing
a positive integer to /proc/acpi/pool_size.
I would appreciate a review of this code. I have provided a boot time
option and a /proc entry to configure this behaviour as an option,
because
it surely needs testing before it becomes the default.
I believe it should become default behaviour for the kernel on all
platforms,
however, since a careful reading of the ACPI
spec suggests that the behaviour of the nx6125 DSDT is in compliance
with
this spec and that any BIOS may potentially require this feature.
Peter
Signed-off-by: Peter Wainwright <[email protected]>