Shreyas B. Prabhu dbd1b8ea43 cpuidle: Fix last_residency division ... Snooze is a poll idle state in powernv and pseries platforms. Snooze has a timeout so that if a CPU stays in snooze for more than target residency of the next available idle state, then it would exit thereby giving chance to the cpuidle governor to re-evaluate and promote the CPU to a deeper idle state. Therefore whenever snooze exits due to this timeout, its last_residency will be target_residency of the next deeper state. Commit e93e59ce5b "cpuidle: Replace ktime_get() with local_clock()" changed the math around last_residency calculation. Specifically, while converting last_residency value from nano- to microseconds, it carries out right shift by 10. Because of that, in snooze timeout exit scenarios last_residency calculated is roughly 2.3% less than target_residency of the next available state. This pattern is picked up by get_typical_interval() in the menu governor and therefore expected_interval in menu_select() is frequently less than the target_residency of any state other than snooze. Due to this we are entering snooze at a higher rate, thereby affecting the single thread performance. Fix this by using more precise division via ktime_us_delta(). Fixes: e93e59ce5b "cpuidle: Replace ktime_get() with local_clock()" Reported-by: Anton Blanchard <anton@samba.org> Bisected-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>		2016-07-04 14:17:34 +02:00
..
governors	cpuidle: menu: Fall back to polling if next timer event is near	2016-03-21 15:50:28 +01:00
coupled.c	cpuidle: coupled: remove unused define cpuidle_coupled_lock	2016-01-27 23:08:46 +01:00
cpuidle-arm.c	ARM: cpuidle: Pass on arm_cpuidle_suspend()'s return value	2016-04-28 15:15:14 +02:00
cpuidle-at91.c
cpuidle-big_little.c
cpuidle-calxeda.c
cpuidle-clps711x.c	drivers/cpuidle: make cpuidle-clps711x.c explicitly non-modular	2015-12-15 00:22:21 +01:00
cpuidle-cps.c
cpuidle-exynos.c	drivers/cpuidle: make cpuidle-exynos.c explicitly non-modular	2015-12-15 00:22:22 +01:00
cpuidle-kirkwood.c
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	powerpc/powernv: remove FW_FEATURE_OPALv3 and just use FW_FEATURE_OPAL	2015-12-17 22:40:54 +11:00
cpuidle-pseries.c
cpuidle-ux500.c	drivers/cpuidle: make cpuidle-ux500.c explicitly non-modular	2015-12-15 00:22:22 +01:00
cpuidle-zynq.c
cpuidle.c	cpuidle: Fix last_residency division	2016-07-04 14:17:34 +02:00
cpuidle.h
driver.c
dt_idle_states.c
dt_idle_states.h
governor.c
Kconfig	cpuidle: Don't enable all governors by default	2016-01-15 22:39:58 +01:00
Kconfig.arm
Kconfig.mips
Kconfig.powerpc
Makefile
sysfs.c