diff mbox

[RFC,V1,1/7] cpuidle: create bootparam "cpuidle.off=1"

Message ID 20110607162922.6848.71783.stgit@tringupt.in.ibm.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Trinabh Gupta June 7, 2011, 4:29 p.m. UTC
From: Len Brown <len.brown@intel.com>

useful for disabling cpuidle to fall back
to architecture-default idle loop

cpuidle drivers and governors will fail to register.
on x86 they'll say so:

intel_idle: intel_idle yielding to (null)
ACPI: acpi_idle yielding to (null)

Signed-off-by: Len Brown <len.brown@intel.com>
---

 Documentation/kernel-parameters.txt |    3 +++
 drivers/cpuidle/cpuidle.c           |   10 ++++++++++
 drivers/cpuidle/cpuidle.h           |    1 +
 drivers/cpuidle/driver.c            |    3 +++
 drivers/cpuidle/governor.c          |    3 +++
 5 files changed, 20 insertions(+), 0 deletions(-)

Comments

Benjamin Herrenschmidt June 17, 2011, 4:29 a.m. UTC | #1
On Tue, 2011-06-07 at 21:59 +0530, Trinabh Gupta wrote:
> From: Len Brown <len.brown@intel.com>
> 
> useful for disabling cpuidle to fall back
> to architecture-default idle loop
> 
> cpuidle drivers and governors will fail to register.
> on x86 they'll say so:
> 
> intel_idle: intel_idle yielding to (null)
> ACPI: acpi_idle yielding to (null)
> 
> Signed-off-by: Len Brown <len.brown@intel.com>
> ---

When you carry over somebody's patch like this you need to also add your
own signed-off-by.

Have those generic changes been reviewed by whoever is in charge of that
cpuidle framework ?

Cheers,
Ben.

>  Documentation/kernel-parameters.txt |    3 +++
>  drivers/cpuidle/cpuidle.c           |   10 ++++++++++
>  drivers/cpuidle/cpuidle.h           |    1 +
>  drivers/cpuidle/driver.c            |    3 +++
>  drivers/cpuidle/governor.c          |    3 +++
>  5 files changed, 20 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index d9a203b..5697faf 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>  			/proc/<pid>/coredump_filter.
>  			See also Documentation/filesystems/proc.txt.
>  
> +	cpuidle.off=1	[CPU_IDLE]
> +			disable the cpuidle sub-system
> +
>  	cpcihp_generic=	[HW,PCI] Generic port I/O CompactPCI driver
>  			Format:
>  			<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index 406be83..a171b9e 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices);
>  static void (*pm_idle_old)(void);
>  
>  static int enabled_devices;
> +static int off __read_mostly;
> +
> +int cpuidle_disabled(void)
> +{
> +	return off;
> +}
>  
>  #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
>  static void cpuidle_kick_cpus(void)
> @@ -397,6 +403,9 @@ static int __init cpuidle_init(void)
>  {
>  	int ret;
>  
> +	if (cpuidle_disabled())
> +		return -ENODEV;
> +
>  	pm_idle_old = pm_idle;
>  
>  	ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
> @@ -408,4 +417,5 @@ static int __init cpuidle_init(void)
>  	return 0;
>  }
>  
> +module_param(off, int, 0444);
>  core_initcall(cpuidle_init);
> diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
> index 33e50d5..38c3fd8 100644
> --- a/drivers/cpuidle/cpuidle.h
> +++ b/drivers/cpuidle/cpuidle.h
> @@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors;
>  extern struct list_head cpuidle_detected_devices;
>  extern struct mutex cpuidle_lock;
>  extern spinlock_t cpuidle_driver_lock;
> +extern int cpuidle_disabled(void);
>  
>  /* idle loop */
>  extern void cpuidle_install_idle_handler(void);
> diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
> index 33e3189..284d7af 100644
> --- a/drivers/cpuidle/driver.c
> +++ b/drivers/cpuidle/driver.c
> @@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv)
>  	if (!drv)
>  		return -EINVAL;
>  
> +	if (cpuidle_disabled())
> +		return -ENODEV;
> +
>  	spin_lock(&cpuidle_driver_lock);
>  	if (cpuidle_curr_driver) {
>  		spin_unlock(&cpuidle_driver_lock);
> diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
> index 724c164..ea2f8e7 100644
> --- a/drivers/cpuidle/governor.c
> +++ b/drivers/cpuidle/governor.c
> @@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov)
>  	if (!gov || !gov->select)
>  		return -EINVAL;
>  
> +	if (cpuidle_disabled())
> +		return -ENODEV;
> +
>  	mutex_lock(&cpuidle_lock);
>  	if (__cpuidle_find_governor(gov->name) == NULL) {
>  		ret = 0;
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
Trinabh Gupta June 21, 2011, 4:36 a.m. UTC | #2
On 06/17/2011 09:59 AM, Benjamin Herrenschmidt wrote:
> On Tue, 2011-06-07 at 21:59 +0530, Trinabh Gupta wrote:
>> From: Len Brown<len.brown@intel.com>
>>
>> useful for disabling cpuidle to fall back
>> to architecture-default idle loop
>>
>> cpuidle drivers and governors will fail to register.
>> on x86 they'll say so:
>>
>> intel_idle: intel_idle yielding to (null)
>> ACPI: acpi_idle yielding to (null)
>>
>> Signed-off-by: Len Brown<len.brown@intel.com>
>> ---

Hi Ben,

Thanks for the review.
>
> When you carry over somebody's patch like this you need to also add your
> own signed-off-by.

Ok, thanks
>
> Have those generic changes been reviewed by whoever is in charge of that
> cpuidle framework ?

These patches were posted by Len Brown himself who is ACPI, Intel Idle
cpuidle driver maintainer. He pulled in most of the patches that were
part of that series (https://lkml.org/lkml/2011/4/2/8)
in 3.0-rc1, but these few patches are still out there. These changes
(removal of pm_idle) have already been agreed upon as they were
initially reported by Peter Zijlstra himself
(http://lkml.org/lkml/2009/8/28/43).

Thanks
-Trinabh
>
> Cheers,
> Ben.
>
>>   Documentation/kernel-parameters.txt |    3 +++
>>   drivers/cpuidle/cpuidle.c           |   10 ++++++++++
>>   drivers/cpuidle/cpuidle.h           |    1 +
>>   drivers/cpuidle/driver.c            |    3 +++
>>   drivers/cpuidle/governor.c          |    3 +++
>>   5 files changed, 20 insertions(+), 0 deletions(-)
>>
>> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
>> index d9a203b..5697faf 100644
>> --- a/Documentation/kernel-parameters.txt
>> +++ b/Documentation/kernel-parameters.txt
>> @@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>>   			/proc/<pid>/coredump_filter.
>>   			See also Documentation/filesystems/proc.txt.
>>
>> +	cpuidle.off=1	[CPU_IDLE]
>> +			disable the cpuidle sub-system
>> +
>>   	cpcihp_generic=	[HW,PCI] Generic port I/O CompactPCI driver
>>   			Format:
>>   			<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
>> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
>> index 406be83..a171b9e 100644
>> --- a/drivers/cpuidle/cpuidle.c
>> +++ b/drivers/cpuidle/cpuidle.c
>> @@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices);
>>   static void (*pm_idle_old)(void);
>>
>>   static int enabled_devices;
>> +static int off __read_mostly;
>> +
>> +int cpuidle_disabled(void)
>> +{
>> +	return off;
>> +}
>>
>>   #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
>>   static void cpuidle_kick_cpus(void)
>> @@ -397,6 +403,9 @@ static int __init cpuidle_init(void)
>>   {
>>   	int ret;
>>
>> +	if (cpuidle_disabled())
>> +		return -ENODEV;
>> +
>>   	pm_idle_old = pm_idle;
>>
>>   	ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
>> @@ -408,4 +417,5 @@ static int __init cpuidle_init(void)
>>   	return 0;
>>   }
>>
>> +module_param(off, int, 0444);
>>   core_initcall(cpuidle_init);
>> diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
>> index 33e50d5..38c3fd8 100644
>> --- a/drivers/cpuidle/cpuidle.h
>> +++ b/drivers/cpuidle/cpuidle.h
>> @@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors;
>>   extern struct list_head cpuidle_detected_devices;
>>   extern struct mutex cpuidle_lock;
>>   extern spinlock_t cpuidle_driver_lock;
>> +extern int cpuidle_disabled(void);
>>
>>   /* idle loop */
>>   extern void cpuidle_install_idle_handler(void);
>> diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
>> index 33e3189..284d7af 100644
>> --- a/drivers/cpuidle/driver.c
>> +++ b/drivers/cpuidle/driver.c
>> @@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv)
>>   	if (!drv)
>>   		return -EINVAL;
>>
>> +	if (cpuidle_disabled())
>> +		return -ENODEV;
>> +
>>   	spin_lock(&cpuidle_driver_lock);
>>   	if (cpuidle_curr_driver) {
>>   		spin_unlock(&cpuidle_driver_lock);
>> diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
>> index 724c164..ea2f8e7 100644
>> --- a/drivers/cpuidle/governor.c
>> +++ b/drivers/cpuidle/governor.c
>> @@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov)
>>   	if (!gov || !gov->select)
>>   		return -EINVAL;
>>
>> +	if (cpuidle_disabled())
>> +		return -ENODEV;
>> +
>>   	mutex_lock(&cpuidle_lock);
>>   	if (__cpuidle_find_governor(gov->name) == NULL) {
>>   		ret = 0;
>>
>> _______________________________________________
>> Linuxppc-dev mailing list
>> Linuxppc-dev@lists.ozlabs.org
>> https://lists.ozlabs.org/listinfo/linuxppc-dev
>
>
diff mbox

Patch

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d9a203b..5697faf 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -546,6 +546,9 @@  bytes respectively. Such letter suffixes can also be entirely omitted.
 			/proc/<pid>/coredump_filter.
 			See also Documentation/filesystems/proc.txt.
 
+	cpuidle.off=1	[CPU_IDLE]
+			disable the cpuidle sub-system
+
 	cpcihp_generic=	[HW,PCI] Generic port I/O CompactPCI driver
 			Format:
 			<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 406be83..a171b9e 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -28,6 +28,12 @@  LIST_HEAD(cpuidle_detected_devices);
 static void (*pm_idle_old)(void);
 
 static int enabled_devices;
+static int off __read_mostly;
+
+int cpuidle_disabled(void)
+{
+	return off;
+}
 
 #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
 static void cpuidle_kick_cpus(void)
@@ -397,6 +403,9 @@  static int __init cpuidle_init(void)
 {
 	int ret;
 
+	if (cpuidle_disabled())
+		return -ENODEV;
+
 	pm_idle_old = pm_idle;
 
 	ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
@@ -408,4 +417,5 @@  static int __init cpuidle_init(void)
 	return 0;
 }
 
+module_param(off, int, 0444);
 core_initcall(cpuidle_init);
diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
index 33e50d5..38c3fd8 100644
--- a/drivers/cpuidle/cpuidle.h
+++ b/drivers/cpuidle/cpuidle.h
@@ -13,6 +13,7 @@  extern struct list_head cpuidle_governors;
 extern struct list_head cpuidle_detected_devices;
 extern struct mutex cpuidle_lock;
 extern spinlock_t cpuidle_driver_lock;
+extern int cpuidle_disabled(void);
 
 /* idle loop */
 extern void cpuidle_install_idle_handler(void);
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 33e3189..284d7af 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -50,6 +50,9 @@  int cpuidle_register_driver(struct cpuidle_driver *drv)
 	if (!drv)
 		return -EINVAL;
 
+	if (cpuidle_disabled())
+		return -ENODEV;
+
 	spin_lock(&cpuidle_driver_lock);
 	if (cpuidle_curr_driver) {
 		spin_unlock(&cpuidle_driver_lock);
diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
index 724c164..ea2f8e7 100644
--- a/drivers/cpuidle/governor.c
+++ b/drivers/cpuidle/governor.c
@@ -81,6 +81,9 @@  int cpuidle_register_governor(struct cpuidle_governor *gov)
 	if (!gov || !gov->select)
 		return -EINVAL;
 
+	if (cpuidle_disabled())
+		return -ENODEV;
+
 	mutex_lock(&cpuidle_lock);
 	if (__cpuidle_find_governor(gov->name) == NULL) {
 		ret = 0;