linux/drivers/acpi
Julius Werner a474a51549 cpuidle: Measure idle state durations with monotonic clock
Many cpuidle drivers measure their time spent in an idle state by
reading the wallclock time before and after idling and calculating the
difference. This leads to erroneous results when the wallclock time gets
updated by another processor in the meantime, adding that clock
adjustment to the idle state's time counter.

If the clock adjustment was negative, the result is even worse due to an
erroneous cast from int to unsigned long long of the last_residency
variable. The negative 32 bit integer will zero-extend and result in a
forward time jump of roughly four billion milliseconds or 1.3 hours on
the idle state residency counter.

This patch changes all affected cpuidle drivers to either use the
monotonic clock for their measurements or make use of the generic time
measurement wrapper in cpuidle.c, which was already working correctly.
Some superfluous CLIs/STIs in the ACPI code are removed (interrupts
should always already be disabled before entering the idle function, and
not get reenabled until the generic wrapper has performed its second
measurement). It also removes the erroneous cast, making sure that
negative residency values are applied correctly even though they should
not appear anymore.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-27 14:17:58 +01:00
..
acpica ACPICA: Table Manager: Merge duplicate code (root table) 2012-09-21 00:35:12 -04:00
apei ACPI, APEI: Fixup common access width firmware bug 2012-07-14 11:01:42 -04:00
ac.c ACPI / PM: Fix unused function warnings for CONFIG_PM_SLEEP 2012-08-10 13:35:32 +02:00
acpi_ipmi.c
acpi_memhotplug.c ACPI: Add _OST support for ACPI memory hotplug 2012-06-04 01:09:21 -04:00
acpi_pad.c Merge branches 'acpi_pad', 'acpica', 'apei-bugzilla-43282', 'battery', 'cpuidle-coupled', 'cpuidle-tweaks', 'intel_idle-ivb', 'ost', 'red-hat-bz-772730', 'thermal', 'thermal-spear' and 'turbostat-v2' into release 2012-07-26 00:03:58 -04:00
battery.c ACPI / PM: Fix unused function warnings for CONFIG_PM_SLEEP 2012-08-10 13:35:32 +02:00
bgrt.c efi: Fix the ACPI BGRT driver for images located in EFI boot services memory 2012-09-29 12:21:03 -07:00
blacklist.c
bus.c ACPI: run _OSC after ACPI_FULL_INITIALIZATION 2012-09-25 00:15:07 -04:00
button.c ACPI/button: convert to module_acpi_driver() 2012-09-21 13:38:29 -04:00
cm_sbs.c
container.c ACPI: Add _OST support for ACPI container hotplug 2012-06-04 01:09:22 -04:00
custom_method.c
debugfs.c
dock.c
ec_sys.c
ec.c ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop 2012-10-06 14:57:33 -04:00
event.c
fan.c ACPI/fan: convert to module_acpi_driver() 2012-09-21 13:39:03 -04:00
glue.c ACPI: Fix memory leak in acpi_bind_one() 2012-10-23 00:53:58 +02:00
hed.c ACPI/hed: convert to module_acpi_driver() 2012-09-21 13:39:25 -04:00
internal.h
Kconfig efi: Fix the ACPI BGRT driver for images located in EFI boot services memory 2012-09-29 12:21:03 -07:00
Makefile ACPI: Reorder IPMI driver before any other ACPI drivers 2012-10-16 18:07:12 -07:00
numa.c ACPI: Only count valid srat memory structures 2012-08-03 00:15:53 -04:00
nvs.c
osl.c ACPICA: Remove argument of acpi_os_wait_events_complete 2012-06-01 11:51:53 -04:00
pci_bind.c
pci_irq.c
pci_link.c
pci_root.c Merge branch 'pci/taku-acpi-pci-host-bridge-v3' into next 2012-09-24 16:36:10 -06:00
pci_slot.c PCI/ACPI: Use acpi_pci_root info rather than looking it up again 2012-09-24 15:29:40 -06:00
power.c ACPI / PM: Use KERN_DEBUG when no power resources are found 2012-09-14 20:54:44 +02:00
proc.c ACPI: Allow ACPI binding with USB-3.0 hub 2012-09-21 13:30:29 -04:00
processor_core.c cpufreq / ACPI: Fix not loading acpi-cpufreq driver regression 2012-07-12 22:39:32 +02:00
processor_driver.c ACPI: missing break 2012-10-26 01:05:56 +02:00
processor_idle.c cpuidle: Measure idle state durations with monotonic clock 2012-11-27 14:17:58 +01:00
processor_perflib.c ACPI: Add fixups for AMD P-state figures 2012-09-09 22:05:02 +02:00
processor_thermal.c
processor_throttling.c
reboot.c
sbs.c ACPI / PM: Fix unused function warnings for CONFIG_PM_SLEEP 2012-08-10 13:35:32 +02:00
sbshc.c ACPI/sbshc: convert to module_acpi_driver() 2012-09-21 13:39:40 -04:00
sbshc.h
scan.c Merge branches 'acpica', 'acpidump', 'intel-idle', 'misc', 'module_acpi_driver-simplify', 'turbostat' and 'usb3' into release 2012-10-06 16:00:32 -04:00
sleep.c Merge branches 'delete-gts-bfs', 'misc', 'novell-bugzilla-757888-numa' and 'osc-pcie' into base 2012-08-03 00:31:23 -04:00
sleep.h
sysfs.c ACPI: replace strlen("string") with sizeof("string") -1 2012-07-26 21:35:28 -04:00
tables.c ACPI: Harden acpi_table_parse_entries() against BIOS bug 2012-10-06 15:51:49 -04:00
thermal.c Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux into thermal 2012-10-09 01:35:52 -04:00
utils.c ACPI: Use ACPICA native way to decode the PLD buffer 2012-09-21 00:31:33 -04:00
video_detect.c acpi/video_detect: blacklist samsung x360 2012-07-28 00:11:48 -04:00
video.c ACPI video: Ignore errors after _DOD evaluation. 2012-11-03 09:52:54 +08:00
wakeup.c