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| author |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-01-16 00:54:53 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-01-19 15:27:49 +0100 |
| commit | 51164251f5c35e6596130ef0de94ffe65fe441e0 (patch) | |
| tree | 914eeadf8095d4fad848451c7928c80ddb17166a | |
| parent | cpuidle: Don't enable all governors by default (diff) | |
| download | linux-dev-51164251f5c35e6596130ef0de94ffe65fe441e0.tar.xz linux-dev-51164251f5c35e6596130ef0de94ffe65fe441e0.zip | |
sched / idle: Drop default_idle_call() fallback from call_cpuidle()
After commit 9c4b2867ed7c (cpuidle: menu: Fix menu_select() for
CPUIDLE_DRIVER_STATE_START == 0) it is clear that menu_select()
cannot return negative values. Moreover, ladder_select_state()
will never return a negative value too, so make find_deepest_state()
return non-negative values too and drop the default_idle_call()
fallback from call_cpuidle().
This eliminates one branch from the idle loop and makes the governors
and find_deepest_state() handle the case when all states have been
disabled from sysfs consistently.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 6 | ||||
| -rw-r--r-- | kernel/sched/idle.c | 6 |
2 files changed, 3 insertions, 9 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 17a6dc0e2111..046423b0c5ca 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -79,9 +79,9 @@ static int find_deepest_state(struct cpuidle_driver *drv, bool freeze) { unsigned int latency_req = 0; - int i, ret = -ENXIO; + int i, ret = 0; - for (i = 0; i < drv->state_count; i++) { + for (i = 1; i < drv->state_count; i++) { struct cpuidle_state *s = &drv->states[i]; struct cpuidle_state_usage *su = &dev->states_usage[i]; @@ -243,7 +243,7 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, * @drv: the cpuidle driver * @dev: the cpuidle device * - * Returns the index of the idle state. + * Returns the index of the idle state. The return value must not be negative. */ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) { diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 4a2ef5a02fd3..34852ee70d54 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -97,12 +97,6 @@ void default_idle_call(void) static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev, int next_state) { - /* Fall back to the default arch idle method on errors. */ - if (next_state < 0) { - default_idle_call(); - return next_state; - } - /* * The idle task must be scheduled, it is pointless to go to idle, just * update no idle residency and return. |