Messages in this thread Patch in this message | | | From | Jacob Pan <> | Subject | [PATCH v4 2/2] cpuidle: allow setting deepest idle | Date | Mon, 28 Nov 2016 13:33:29 -0800 |
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When idle injection is used to cap power, we need to override governor's choice of idle states. This patch allows caller to select the deepest idle state on a CPU therefore achieve the maximum potential power saving.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> --- drivers/cpuidle/cpuidle.c | 11 +++++++++++ include/linux/cpuidle.h | 4 +++- kernel/sched/idle.c | 13 ++++++++----- 3 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index c73207a..887a52a 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -97,6 +97,17 @@ static int find_deepest_state(struct cpuidle_driver *drv, return ret; } +/* Set the current cpu to use the deepest idle state, override governors */ +void cpuidle_use_deepest_state(bool enable) +{ + struct cpuidle_device *dev; + + preempt_disable(); + dev = cpuidle_get_device(); + dev->use_deepest_state = enable; + preempt_enable(); +} + #ifdef CONFIG_SUSPEND /** * cpuidle_find_deepest_state - Find the deepest available idle state. diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index bb31373..97c169b 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -74,6 +74,7 @@ struct cpuidle_state { struct cpuidle_device { unsigned int registered:1; unsigned int enabled:1; + unsigned int use_deepest_state:1; unsigned int cpu; int last_residency; @@ -192,11 +193,12 @@ static inline struct cpuidle_driver *cpuidle_get_cpu_driver( static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } #endif -#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND) +#ifdef CONFIG_CPU_IDLE extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev); extern int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev); +extern void cpuidle_use_deepest_state(bool enable); #else static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index f01d494..6a4bae0 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -164,11 +164,14 @@ static void cpuidle_idle_call(void) * timekeeping to prevent timer interrupts from kicking us out of idle * until a proper wakeup interrupt happens. */ - if (idle_should_freeze()) { - entered_state = cpuidle_enter_freeze(drv, dev); - if (entered_state > 0) { - local_irq_enable(); - goto exit_idle; + + if (idle_should_freeze() || dev->use_deepest_state) { + if (idle_should_freeze()) { + entered_state = cpuidle_enter_freeze(drv, dev); + if (entered_state > 0) { + local_irq_enable(); + goto exit_idle; + } } next_state = cpuidle_find_deepest_state(drv, dev); -- 1.9.1
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