From e978aa7d7d57d04eb5f88a7507c4fb98577def77 Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:09 +0530 Subject: cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state Cpuidle governor only suggests the state to enter using the governor->select() interface, but allows the low level driver to override the recommended state. The actual entered state may be different because of software or hardware demotion. Software demotion is done by the back-end cpuidle driver and can be accounted correctly. Current cpuidle code uses last_state field to capture the actual state entered and based on that updates the statistics for the state entered. Ideally the driver enter routine should update the counters, and it should return the state actually entered rather than the time spent there. The generic cpuidle code should simply handle where the counters live in the sysfs namespace, not updating the counters. Reference: https://lkml.org/lkml/2011/3/25/52 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- drivers/cpuidle/governors/ladder.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/cpuidle/governors/ladder.c') diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index 12c98900dcf8..6a686a76711f 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -153,11 +153,24 @@ static int ladder_enable_device(struct cpuidle_device *dev) return 0; } +/** + * ladder_reflect - update the correct last_state_idx + * @dev: the CPU + * @index: the index of actual state entered + */ +static void ladder_reflect(struct cpuidle_device *dev, int index) +{ + struct ladder_device *ldev = &__get_cpu_var(ladder_devices); + if (index > 0) + ldev->last_state_idx = index; +} + static struct cpuidle_governor ladder_governor = { .name = "ladder", .rating = 10, .enable = ladder_enable_device, .select = ladder_select_state, + .reflect = ladder_reflect, .owner = THIS_MODULE, }; -- cgit v1.2.1 From 46bcfad7a819bd17ac4e831b04405152d59784ab Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:42 +0530 Subject: cpuidle: Single/Global registration of idle states This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- drivers/cpuidle/governors/ladder.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) (limited to 'drivers/cpuidle/governors/ladder.c') diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index 6a686a76711f..ef6b9e4727a7 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -60,9 +60,11 @@ static inline void ladder_do_selection(struct ladder_device *ldev, /** * ladder_select_state - selects the next state to enter + * @drv: cpuidle driver * @dev: the CPU */ -static int ladder_select_state(struct cpuidle_device *dev) +static int ladder_select_state(struct cpuidle_driver *drv, + struct cpuidle_device *dev) { struct ladder_device *ldev = &__get_cpu_var(ladder_devices); struct ladder_device_state *last_state; @@ -77,15 +79,17 @@ static int ladder_select_state(struct cpuidle_device *dev) last_state = &ldev->states[last_idx]; - if (dev->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID) - last_residency = cpuidle_get_last_residency(dev) - dev->states[last_idx].exit_latency; + if (drv->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID) { + last_residency = cpuidle_get_last_residency(dev) - \ + drv->states[last_idx].exit_latency; + } else last_residency = last_state->threshold.promotion_time + 1; /* consider promotion */ - if (last_idx < dev->state_count - 1 && + if (last_idx < drv->state_count - 1 && last_residency > last_state->threshold.promotion_time && - dev->states[last_idx + 1].exit_latency <= latency_req) { + drv->states[last_idx + 1].exit_latency <= latency_req) { last_state->stats.promotion_count++; last_state->stats.demotion_count = 0; if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) { @@ -96,11 +100,11 @@ static int ladder_select_state(struct cpuidle_device *dev) /* consider demotion */ if (last_idx > CPUIDLE_DRIVER_STATE_START && - dev->states[last_idx].exit_latency > latency_req) { + drv->states[last_idx].exit_latency > latency_req) { int i; for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) { - if (dev->states[i].exit_latency <= latency_req) + if (drv->states[i].exit_latency <= latency_req) break; } ladder_do_selection(ldev, last_idx, i); @@ -123,9 +127,11 @@ static int ladder_select_state(struct cpuidle_device *dev) /** * ladder_enable_device - setup for the governor + * @drv: cpuidle driver * @dev: the CPU */ -static int ladder_enable_device(struct cpuidle_device *dev) +static int ladder_enable_device(struct cpuidle_driver *drv, + struct cpuidle_device *dev) { int i; struct ladder_device *ldev = &per_cpu(ladder_devices, dev->cpu); @@ -134,8 +140,8 @@ static int ladder_enable_device(struct cpuidle_device *dev) ldev->last_state_idx = CPUIDLE_DRIVER_STATE_START; - for (i = 0; i < dev->state_count; i++) { - state = &dev->states[i]; + for (i = 0; i < drv->state_count; i++) { + state = &drv->states[i]; lstate = &ldev->states[i]; lstate->stats.promotion_count = 0; @@ -144,7 +150,7 @@ static int ladder_enable_device(struct cpuidle_device *dev) lstate->threshold.promotion_count = PROMOTION_COUNT; lstate->threshold.demotion_count = DEMOTION_COUNT; - if (i < dev->state_count - 1) + if (i < drv->state_count - 1) lstate->threshold.promotion_time = state->exit_latency; if (i > 0) lstate->threshold.demotion_time = state->exit_latency; -- cgit v1.2.1