leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID

Browse Source 
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@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Len Brown 2014-12-16 01:52:08 -05:00 committed by Rafael J. Wysocki
parent b73026b9c9
commit 62c4cf97e8
2 changed files with 0 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/acpi/processor_idle.c
View File

@ -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;

3
include/linux/cpuidle.h
View File

@ -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)
{