linux/drivers/cpuidle
Rik van Riel efddfd90fb cpuidle,menu: smooth out measured_us calculation
The cpuidle state tables contain the maximum exit latency for each
cpuidle state. On x86, that is the exit latency for when the entire
package goes into that same idle state.

However, a lot of the time we only go into the core idle state,
not the package idle state. This means we see a much smaller exit
latency.

We have no way to detect whether we went into the core or package
idle state while idle, and that is ok.

However, the current menu_update logic does have the potential to
trip up the repeating pattern detection in get_typical_interval.
If the system is experiencing an exit latency near the idle state's
exit latency, some of the samples will have exit_us subtracted,
while others will not. This turns a repeating pattern into mush,
potentially breaking get_typical_interval.

Furthermore, for smaller sleep intervals, we know the chance that
all the cores in the package went to the same idle state are fairly
small. Dividing the measured_us by two, instead of subtracting the
full exit latency when hitting a small measured_us, will reduce the
error.

Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-17 02:24:25 +01:00
..
governors cpuidle,menu: smooth out measured_us calculation 2015-11-17 02:24:25 +01:00
coupled.c cpuidle/coupled: Add sanity check for safe_state_index 2015-09-03 03:05:47 +02:00
cpuidle-arm.c ARM: cpuidle: Register per cpuidle device 2015-03-24 14:46:25 +01:00
cpuidle-at91.c drivers/cpuidle: Convert non-modular drivers to use builtin_platform_driver 2015-06-16 14:12:38 -04:00
cpuidle-big_little.c ARM: MCPM: remove residency argument from mcpm_cpu_suspend() 2015-05-06 11:47:10 -04:00
cpuidle-calxeda.c ARM: migrate to common PSCI client code 2015-08-03 15:38:39 +01:00
cpuidle-clps711x.c cpuidle: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00
cpuidle-cps.c cpuidle: Invert CPUIDLE_FLAG_TIME_VALID logic 2014-11-12 21:17:27 +01:00
cpuidle-exynos.c ARM: SoC fixes for v4.1 2015-04-22 09:03:30 -07:00
cpuidle-kirkwood.c ARM: cpuidle: Remove duplicate header inclusion 2015-03-23 18:03:11 +01:00
cpuidle-mvebu-v7.c cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver 2015-10-23 12:40:48 +02:00
cpuidle-powernv.c tick/idle/powerpc: Do not register idle states with CPUIDLE_FLAG_TIMER_STOP set in periodic mode 2015-06-26 03:28:49 +02:00
cpuidle-pseries.c cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state 2015-06-22 15:15:15 +02:00
cpuidle-ux500.c ARM: cpuidle: Remove duplicate header inclusion 2015-03-23 18:03:11 +01:00
cpuidle-zynq.c drivers/cpuidle: Convert non-modular drivers to use builtin_platform_driver 2015-06-16 14:12:38 -04:00
cpuidle.c Power management and ACPI material for v4.3-rc1 2015-09-01 19:45:46 -07:00
cpuidle.h cpuidle/coupled: Add sanity check for safe_state_index 2015-09-03 03:05:47 +02:00
driver.c cpuidle/coupled: Add sanity check for safe_state_index 2015-09-03 03:05:47 +02:00
dt_idle_states.c Merge back earlier cpuidle material for 3.19-rc1. 2014-11-21 16:31:42 +01:00
dt_idle_states.h drivers: cpuidle: implement DT based idle states infrastructure 2014-09-25 10:52:20 +02:00
governor.c cpuidle: Replace strnicmp with strncasecmp 2014-09-25 01:17:10 +02:00
Kconfig ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64 2015-03-24 10:16:11 +01:00
Kconfig.arm ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64 2015-03-24 10:16:11 +01:00
Kconfig.mips MIPS: Kconfig: Add missing MIPS_CPS dependencies to PM and cpuidle 2014-10-23 19:58:05 +02:00
Kconfig.powerpc powerpc/powernv/cpuidle: Back-end cpuidle driver for powernv platform. 2014-01-29 17:02:24 +11:00
Makefile ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64 2015-03-24 10:16:11 +01:00
sysfs.c cpuidle: remove state_count field from struct cpuidle_device 2015-04-03 13:15:50 +02:00