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Message-ID: <20090901113840.GH7599@linux.vnet.ibm.com>
Date: Tue, 1 Sep 2009 17:08:40 +0530
From: Arun R Bharadwaj <arun@...ux.vnet.ibm.com>
To: Joel Schopp <jschopp@...tin.ibm.com>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Ingo Molnar <mingo@...e.hu>,
Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
Dipankar Sarma <dipankar@...ibm.com>,
Balbir Singh <balbir@...ibm.com>,
Gautham R Shenoy <ego@...ibm.com>,
Arun Bharadwaj <arun@...ux.vnet.ibm.com>
Cc: linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
Arun Bharadwaj <arun@...ux.vnet.ibm.com>
Subject: [v4 PATCH 1/5]: cpuidle: Cleanup drivers/cpuidle/cpuidle.c
* Arun R Bharadwaj <arun@...ux.vnet.ibm.com> [2009-09-01 17:07:04]:
Cleanup drivers/cpuidle/cpuidle.c
Cpuidle maintains a pm_idle_old void pointer because, currently in x86
there is no clean way of registering and unregistering a idle function.
So remove pm_idle_old and leave the responsibility of maintaining the
list of registered idle loops to the architecture specific code. If the
architecture registers cpuidle_idle_call as its idle loop, only then
this loop is called.
Also remove unwanted functions cpuidle_[un]install_idle_handler,
cpuidle_kick_cpus()
Signed-off-by: Arun R Bharadwaj <arun@...ux.vnet.ibm.com>
---
drivers/cpuidle/cpuidle.c | 51 +++++++++++++++------------------------------
drivers/cpuidle/governor.c | 3 --
2 files changed, 17 insertions(+), 37 deletions(-)
Index: linux.trees.git/drivers/cpuidle/cpuidle.c
===================================================================
--- linux.trees.git.orig/drivers/cpuidle/cpuidle.c
+++ linux.trees.git/drivers/cpuidle/cpuidle.c
@@ -24,9 +24,14 @@ DEFINE_PER_CPU(struct cpuidle_device *,
DEFINE_MUTEX(cpuidle_lock);
LIST_HEAD(cpuidle_detected_devices);
-static void (*pm_idle_old)(void);
static int enabled_devices;
+static int idle_function_registered;
+
+struct idle_function_desc cpuidle_idle_desc = {
+ .name = "cpuidle_loop",
+ .idle_func = cpuidle_idle_call,
+};
#if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
static void cpuidle_kick_cpus(void)
@@ -54,13 +59,10 @@ static void cpuidle_idle_call(void)
/* check if the device is ready */
if (!dev || !dev->enabled) {
- if (pm_idle_old)
- pm_idle_old();
- else
#if defined(CONFIG_ARCH_HAS_DEFAULT_IDLE)
- default_idle();
+ default_idle();
#else
- local_irq_enable();
+ local_irq_enable();
#endif
return;
}
@@ -94,35 +96,11 @@ static void cpuidle_idle_call(void)
}
/**
- * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
- */
-void cpuidle_install_idle_handler(void)
-{
- if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
- /* Make sure all changes finished before we switch to new idle */
- smp_wmb();
- pm_idle = cpuidle_idle_call;
- }
-}
-
-/**
- * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler
- */
-void cpuidle_uninstall_idle_handler(void)
-{
- if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) {
- pm_idle = pm_idle_old;
- cpuidle_kick_cpus();
- }
-}
-
-/**
* cpuidle_pause_and_lock - temporarily disables CPUIDLE
*/
void cpuidle_pause_and_lock(void)
{
mutex_lock(&cpuidle_lock);
- cpuidle_uninstall_idle_handler();
}
EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock);
@@ -132,7 +110,6 @@ EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock
*/
void cpuidle_resume_and_unlock(void)
{
- cpuidle_install_idle_handler();
mutex_unlock(&cpuidle_lock);
}
@@ -287,6 +264,12 @@ static int __cpuidle_register_device(str
return 0;
}
+static void register_cpuidle_idle_function(void)
+{
+ register_idle_function(&cpuidle_idle_desc);
+
+ idle_function_registered = 1;
+}
/**
* cpuidle_register_device - registers a CPU's idle PM feature
* @dev: the cpu
@@ -303,7 +286,9 @@ int cpuidle_register_device(struct cpuid
}
cpuidle_enable_device(dev);
- cpuidle_install_idle_handler();
+
+ if (!idle_function_registered)
+ register_cpuidle_idle_function();
mutex_unlock(&cpuidle_lock);
@@ -382,8 +367,6 @@ static int __init cpuidle_init(void)
{
int ret;
- pm_idle_old = pm_idle;
-
ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
if (ret)
return ret;
Index: linux.trees.git/drivers/cpuidle/governor.c
===================================================================
--- linux.trees.git.orig/drivers/cpuidle/governor.c
+++ linux.trees.git/drivers/cpuidle/governor.c
@@ -48,8 +48,6 @@ int cpuidle_switch_governor(struct cpuid
if (gov == cpuidle_curr_governor)
return 0;
- cpuidle_uninstall_idle_handler();
-
if (cpuidle_curr_governor) {
list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
cpuidle_disable_device(dev);
@@ -63,7 +61,6 @@ int cpuidle_switch_governor(struct cpuid
return -EINVAL;
list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
cpuidle_enable_device(dev);
- cpuidle_install_idle_handler();
printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
}
--
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