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Date: Sun, 27 Apr 2014 14:54:08 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM list <linux-pm@...r.kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
'Daniel Lezcano' <daniel.lezcano@...aro.org>,
Ingo Molnar <mingo@...nel.org>,
Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH 1/2] cpuidle: Combine cpuidle_enabled() with cpuidle_select()
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Since both cpuidle_enabled() and cpuidle_select() are only called by
cpuidle_idle_call(), it is not really useful to keep them separate
and combining them will help to avoid complicating cpuidle_idle_call()
even further if governors are changed to return error codes sometimes.
This code modification shouldn't lead to any functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
drivers/cpuidle/cpuidle.c | 26 ++++++--------------------
include/linux/cpuidle.h | 5 -----
kernel/sched/idle.c | 20 +++++++-------------
3 files changed, 13 insertions(+), 38 deletions(-)
Index: linux-pm/kernel/sched/idle.c
===================================================================
--- linux-pm.orig/kernel/sched/idle.c
+++ linux-pm/kernel/sched/idle.c
@@ -100,19 +100,13 @@ static void cpuidle_idle_call(void)
rcu_idle_enter();
/*
- * Check if the cpuidle framework is ready, otherwise fallback
- * to the default arch specific idle method
+ * Ask the cpuidle framework to choose a convenient idle state.
+ * Fall back to the default arch specific idle method on errors.
*/
- ret = cpuidle_enabled(drv, dev);
-
- if (!ret) {
- /*
- * Ask the governor to choose an idle state it thinks
- * it is convenient to go to. There is *always* a
- * convenient idle state
- */
- next_state = cpuidle_select(drv, dev);
+ next_state = cpuidle_select(drv, dev);
+ ret = next_state;
+ if (ret >= 0) {
/*
* The idle task must be scheduled, it is pointless to
* go to idle, just update no idle residency and get
@@ -139,7 +133,7 @@ static void cpuidle_idle_call(void)
CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
&dev->cpu);
- if (!ret) {
+ if (ret >= 0) {
trace_cpu_idle_rcuidle(next_state, dev->cpu);
/*
@@ -174,7 +168,7 @@ static void cpuidle_idle_call(void)
* We can't use the cpuidle framework, let's use the default
* idle routine
*/
- if (ret)
+ if (ret < 0)
arch_cpu_idle();
__current_set_polling();
Index: linux-pm/drivers/cpuidle/cpuidle.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/cpuidle.c
+++ linux-pm/drivers/cpuidle/cpuidle.c
@@ -65,26 +65,6 @@ int cpuidle_play_dead(void)
}
/**
- * cpuidle_enabled - check if the cpuidle framework is ready
- * @dev: cpuidle device for this cpu
- * @drv: cpuidle driver for this cpu
- *
- * Return 0 on success, otherwise:
- * -NODEV : the cpuidle framework is not available
- * -EBUSY : the cpuidle framework is not initialized
- */
-int cpuidle_enabled(struct cpuidle_driver *drv, struct cpuidle_device *dev)
-{
- if (off || !initialized)
- return -ENODEV;
-
- if (!drv || !dev || !dev->enabled)
- return -EBUSY;
-
- return 0;
-}
-
-/**
* cpuidle_enter_state - enter the state and update stats
* @dev: cpuidle device for this cpu
* @drv: cpuidle driver for this cpu
@@ -138,6 +118,12 @@ int cpuidle_enter_state(struct cpuidle_d
*/
int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
+ if (off || !initialized)
+ return -ENODEV;
+
+ if (!drv || !dev || !dev->enabled)
+ return -EBUSY;
+
return cpuidle_curr_governor->select(drv, dev);
}
Index: linux-pm/include/linux/cpuidle.h
===================================================================
--- linux-pm.orig/include/linux/cpuidle.h
+++ linux-pm/include/linux/cpuidle.h
@@ -120,8 +120,6 @@ struct cpuidle_driver {
#ifdef CONFIG_CPU_IDLE
extern void disable_cpuidle(void);
-extern int cpuidle_enabled(struct cpuidle_driver *drv,
- struct cpuidle_device *dev);
extern int cpuidle_select(struct cpuidle_driver *drv,
struct cpuidle_device *dev);
extern int cpuidle_enter(struct cpuidle_driver *drv,
@@ -149,9 +147,6 @@ extern int cpuidle_play_dead(void);
extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
#else
static inline void disable_cpuidle(void) { }
-static inline int cpuidle_enabled(struct cpuidle_driver *drv,
- struct cpuidle_device *dev)
-{return -ENODEV; }
static inline int cpuidle_select(struct cpuidle_driver *drv,
struct cpuidle_device *dev)
{return -ENODEV; }
--
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