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authorLinus Torvalds <torvalds@linux-foundation.org>2008-08-15 12:47:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-15 12:47:16 -0700
commit40a342664078ebcb4006a89af96f7982fac36032 (patch)
treee8bcaac5a116ab9a95ffa5d04046b0aa2159d59e /drivers
parent4ad193b43f6da6f15e19eda338c71e5b41383912 (diff)
parent22d9aac23562ea0e921db152f11cf39e3c2b9945 (diff)
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.c26
-rw-r--r--drivers/cpuidle/governors/menu.c42
2 files changed, 50 insertions, 18 deletions
diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c
index ba7b9a6b17a..a4bec3f919a 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 78d77c5dc35..8d7cf3f3145 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;
}
}