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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-15 19:47:16 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-15 19:47:16 (GMT) |
commit | 40a342664078ebcb4006a89af96f7982fac36032 (patch) | |
tree | e8bcaac5a116ab9a95ffa5d04046b0aa2159d59e /drivers | |
parent | 4ad193b43f6da6f15e19eda338c71e5b41383912 (diff) | |
parent | 22d9aac23562ea0e921db152f11cf39e3c2b9945 (diff) | |
download | linux-fsl-qoriq-40a342664078ebcb4006a89af96f7982fac36032.tar.xz |
Merge branch 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-2.6
* 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-2.6:
cpuidle: Make ladder governor honor latency requirements fully
cpuidle: Menu governor fix wrong usage of measured_us
cpuidle: Do not use poll_idle unless user asks for it
x86: Fix ioremap off by one BUG
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/cpuidle/governors/ladder.c | 26 | ||||
-rw-r--r-- | drivers/cpuidle/governors/menu.c | 42 |
2 files changed, 50 insertions, 18 deletions
diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index ba7b9a6..a4bec3f 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -67,10 +67,17 @@ static int ladder_select_state(struct cpuidle_device *dev) struct ladder_device *ldev = &__get_cpu_var(ladder_devices); struct ladder_device_state *last_state; int last_residency, last_idx = ldev->last_state_idx; + int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY); if (unlikely(!ldev)) return 0; + /* Special case when user has set very strict latency requirement */ + if (unlikely(latency_req == 0)) { + ladder_do_selection(ldev, last_idx, 0); + return 0; + } + last_state = &ldev->states[last_idx]; if (dev->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID) @@ -81,8 +88,7 @@ static int ladder_select_state(struct cpuidle_device *dev) /* consider promotion */ if (last_idx < dev->state_count - 1 && last_residency > last_state->threshold.promotion_time && - dev->states[last_idx + 1].exit_latency <= - pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) { + dev->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) { @@ -92,7 +98,19 @@ static int ladder_select_state(struct cpuidle_device *dev) } /* consider demotion */ - if (last_idx > 0 && + if (last_idx > CPUIDLE_DRIVER_STATE_START && + dev->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) + break; + } + ladder_do_selection(ldev, last_idx, i); + return i; + } + + if (last_idx > CPUIDLE_DRIVER_STATE_START && last_residency < last_state->threshold.demotion_time) { last_state->stats.demotion_count++; last_state->stats.promotion_count = 0; @@ -117,7 +135,7 @@ static int ladder_enable_device(struct cpuidle_device *dev) struct ladder_device_state *lstate; struct cpuidle_state *state; - ldev->last_state_idx = 0; + ldev->last_state_idx = CPUIDLE_DRIVER_STATE_START; for (i = 0; i < dev->state_count; i++) { state = &dev->states[i]; diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 78d77c5..8d7cf3f 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -34,21 +34,28 @@ static DEFINE_PER_CPU(struct menu_device, menu_devices); static int menu_select(struct cpuidle_device *dev) { struct menu_device *data = &__get_cpu_var(menu_devices); + int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY); int i; + /* Special case when user has set very strict latency requirement */ + if (unlikely(latency_req == 0)) { + data->last_state_idx = 0; + return 0; + } + /* determine the expected residency time */ data->expected_us = (u32) ktime_to_ns(tick_nohz_get_sleep_length()) / 1000; /* find the deepest idle state that satisfies our constraints */ - for (i = 1; i < dev->state_count; i++) { + for (i = CPUIDLE_DRIVER_STATE_START + 1; i < dev->state_count; i++) { struct cpuidle_state *s = &dev->states[i]; if (s->target_residency > data->expected_us) break; if (s->target_residency > data->predicted_us) break; - if (s->exit_latency > pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) + if (s->exit_latency > latency_req) break; } @@ -67,9 +74,9 @@ static void menu_reflect(struct cpuidle_device *dev) { struct menu_device *data = &__get_cpu_var(menu_devices); int last_idx = data->last_state_idx; - unsigned int measured_us = - cpuidle_get_last_residency(dev) + data->elapsed_us; + unsigned int last_idle_us = cpuidle_get_last_residency(dev); struct cpuidle_state *target = &dev->states[last_idx]; + unsigned int measured_us; /* * Ugh, this idle state doesn't support residency measurements, so we @@ -77,20 +84,27 @@ static void menu_reflect(struct cpuidle_device *dev) * for one full standard timer tick. However, be aware that this * could potentially result in a suboptimal state transition. */ - if (!(target->flags & CPUIDLE_FLAG_TIME_VALID)) - measured_us = USEC_PER_SEC / HZ; + if (unlikely(!(target->flags & CPUIDLE_FLAG_TIME_VALID))) + last_idle_us = USEC_PER_SEC / HZ; + + /* + * measured_us and elapsed_us are the cumulative idle time, since the + * last time we were woken out of idle by an interrupt. + */ + if (data->elapsed_us <= data->elapsed_us + last_idle_us) + measured_us = data->elapsed_us + last_idle_us; + else + measured_us = -1; + + /* Predict time until next break event */ + data->predicted_us = max(measured_us, data->last_measured_us); - /* Predict time remaining until next break event */ - if (measured_us + BREAK_FUZZ < data->expected_us - target->exit_latency) { - data->predicted_us = max(measured_us, data->last_measured_us); + if (last_idle_us + BREAK_FUZZ < + data->expected_us - target->exit_latency) { data->last_measured_us = measured_us; data->elapsed_us = 0; } else { - if (data->elapsed_us < data->elapsed_us + measured_us) - data->elapsed_us = measured_us; - else - data->elapsed_us = -1; - data->predicted_us = max(measured_us, data->last_measured_us); + data->elapsed_us = measured_us; } } |