On 12/16/2014 07:52 AM, Len Brown wrote:
From: Len Brown <len.brown@xxxxxxxxx>
CPUIDLE_FLAG_TIME_INVALID is no longer checked
by menu or ladder cpuidle governors, so don't
bother setting or defining it.
It was originally invented to account for the fact that
acpi_safe_halt() enables interrupts to invoke HLT.
That would allow interrupt service routines to be included
in the last_idle duration measurements made in cpuidle_enter_state(),
potentially returning a duration much larger than reality.
But menu and ladder can gracefully handle erroneously large duration
intervals without checking for CPUIDLE_FLAG_TIME_INVALID.
Further, if they don't check CPUIDLE_FLAG_TIME_INVALID, they
can also benefit from the instances when the duration interval
is not erroneously large.
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
---
drivers/acpi/processor_idle.c | 2 --
include/linux/cpuidle.h | 3 ---
2 files changed, 5 deletions(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 4995365..87b704e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -985,8 +985,6 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
state->flags = 0;
switch (cx->type) {
case ACPI_STATE_C1:
- if (cx->entry_method != ACPI_CSTATE_FFH)
- state->flags |= CPUIDLE_FLAG_TIME_INVALID;
state->enter = acpi_idle_enter_c1;
state->enter_dead = acpi_idle_play_dead;
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index a07e087..ab70f3b 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -53,7 +53,6 @@ struct cpuidle_state {
};
/* Idle State Flags */
-#define CPUIDLE_FLAG_TIME_INVALID (0x01) /* is residency time measurable? */
#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
@@ -89,8 +88,6 @@ DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
/**
* cpuidle_get_last_residency - retrieves the last state's residency time
* @dev: the target CPU
- *
- * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_INVALID is set
*/
static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
{
--
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