The core change is to split the cpuidle_device structure into parts that can be global and parts that has to remain per-cpu. The per-cpu pieces are mostly generic statistics that can be independent of current running driver. Motivation: * Simplify the cpuidle subsystem framework and have registration/unregistration done by single cpu. * Have single copy of cpuidle_states structure and thus reduce memory consumption. * Only in very rare cases asymmetric C-states exist which can be handled within the cpuidle driver. Most architectures do not have asymmetric C-states. * References: https://lkml.org/lkml/2011/2/10/37 https://lkml.org/lkml/2011/3/25/52 The first couple of patches in the series move the statistics accounting part to withing cpuidle driver; which ensures correctness in updation of statistics. Moving statistics within cpuidle driver is also required to make cpuidle_state not writable and thus global. Third patch splits the per-cpu part out of cpuidle_state structure and the fourth patch makes the cpuidle_state global. Please refer to https://lkml.org/lkml/2011/3/25/52 . Version 1 of the series is at https://lkml.org/lkml/2011/3/22/161 This patch series applies on top of 2.6.38 and is tested on x86 Nehalem system with multiple ACPI C-States. To Do: 1. This patch series works only for acpi_idle driver. Changes would have to be done for other idle drivers i.e. intel_idle, at91_idle_driver, davinci_idle_driver, kirkwood_idle_driver, omap3_idle_driver. 2. Make ladder governor follow changed API. Currently it works for menu governor only. Thanks, -Trinabh --- Trinabh Gupta (4): Single/Global registration of idle states Split cpuidle_state structure and move per-cpu statistics fields Remove CPUIDLE_FLAG_IGNORE and dev->prepare() Move dev->last_residency update to driver enter routine; remove dev->last_state drivers/acpi/processor_driver.c | 18 ---- drivers/acpi/processor_idle.c | 184 ++++++++++++++++++++++++++++++-------- drivers/cpuidle/cpuidle.c | 80 +++++------------ drivers/cpuidle/driver.c | 26 +++++ drivers/cpuidle/governors/menu.c | 25 +++-- drivers/cpuidle/sysfs.c | 18 ++-- include/linux/cpuidle.h | 49 ++++++---- 7 files changed, 247 insertions(+), 153 deletions(-) -- _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
