kernel_optimize_test/include/acpi
Len Brown 718be4aaf3 ACPI: skip checking BM_STS if the BIOS doesn't ask for it
It turns out that there is a bit in the _CST for Intel FFH C3
that tells the OS if we should be checking BM_STS or not.

Linux has been unconditionally checking BM_STS.
If the chip-set is configured to enable BM_STS,
it can retard or completely prevent entry into
deep C-states -- as illustrated by turbostat:

http://userweb.kernel.org/~lenb/acpi/utils/pmtools/turbostat/

ref: Intel Processor Vendor-Specific ACPI Interface Specification
table 4 "_CST FFH GAS Field Encoding"
Bit 1: Set to 1 if OSPM should use Bus Master avoidance for this C-state

https://bugzilla.kernel.org/show_bug.cgi?id=15886

Signed-off-by: Len Brown <len.brown@intel.com>
2010-07-22 16:54:27 -04:00
..
platform
acexcep.h
acnames.h
acoutput.h
acpi_bus.h
acpi_drivers.h
acpi_numa.h
acpi.h
acpiosxf.h
acpixf.h
acrestyp.h
actbl1.h
actbl2.h
actbl.h
actypes.h
apei.h
atomicio.h
button.h
container.h
hed.h
pdc_intel.h
processor.h
reboot.h
video.h