Re: [PATCH] PM / QOS: Remove the global notifiers
From: Ulf Hansson
Date: Mon Mar 13 2017 - 12:04:13 EST
On 13 March 2017 at 17:01, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 22 February 2017 at 09:28, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
>> They were never used in the kernel, not sure why they got merged into
>> the kernel though. Get rid of them.
>
> commit b66213cdb002b08b29603d488c451dfe25e2ca20
> Author: Jean Pihet <j-pihet@xxxxxx>
> Date: Thu Aug 25 15:35:47 2011 +0200
>
> PM QoS: Add global notification mechanism for device constraints
>
> Add a global notification chain that gets called upon changes to the
> aggregated constraint value for any device.
> The notification callbacks are passing the full constraint request data
> in order for the callees to have access to it. The current use is for the
> platform low-level code to access the target device of the constraint.
>
> Signed-off-by: Jean Pihet <j-pihet@xxxxxx>
> Reviewed-by: Kevin Hilman <khilman@xxxxxx>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
>
> It was a while ago since they were added, but it seems like
Slipped on the keyboard, sorry for the noise.
I was about to say, that it was a while ago these were added, but
still not being used. Thus let's remove them.
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Kind regards
Uffe
>
>>
>> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
>> ---
>> Documentation/power/pm_qos_interface.txt | 13 +--------
>> drivers/base/power/qos.c | 50 +++-----------------------------
>> include/linux/pm_qos.h | 8 -----
>> 3 files changed, 5 insertions(+), 66 deletions(-)
>>
>> diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt
>> index 129f7c0e1483..21d2d48f87a2 100644
>> --- a/Documentation/power/pm_qos_interface.txt
>> +++ b/Documentation/power/pm_qos_interface.txt
>> @@ -163,8 +163,7 @@ of flags and remove sysfs attributes pm_qos_no_power_off and pm_qos_remote_wakeu
>> under the device's power directory.
>>
>> Notification mechanisms:
>> -The per-device PM QoS framework has 2 different and distinct notification trees:
>> -a per-device notification tree and a global notification tree.
>> +The per-device PM QoS framework has a per-device notification tree.
>>
>> int dev_pm_qos_add_notifier(device, notifier):
>> Adds a notification callback function for the device.
>> @@ -174,16 +173,6 @@ is changed (for resume latency device PM QoS only).
>> int dev_pm_qos_remove_notifier(device, notifier):
>> Removes the notification callback function for the device.
>>
>> -int dev_pm_qos_add_global_notifier(notifier):
>> -Adds a notification callback function in the global notification tree of the
>> -framework.
>> -The callback is called when the aggregated value for any device is changed
>> -(for resume latency device PM QoS only).
>> -
>> -int dev_pm_qos_remove_global_notifier(notifier):
>> -Removes the notification callback function from the global notification tree
>> -of the framework.
>> -
>>
>> Active state latency tolerance
>>
>> diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
>> index d888d9869b6a..271bec73185e 100644
>> --- a/drivers/base/power/qos.c
>> +++ b/drivers/base/power/qos.c
>> @@ -17,12 +17,9 @@
>> *
>> * This QoS design is best effort based. Dependents register their QoS needs.
>> * Watchers register to keep track of the current QoS needs of the system.
>> - * Watchers can register different types of notification callbacks:
>> - * . a per-device notification callback using the dev_pm_qos_*_notifier API.
>> - * The notification chain data is stored in the per-device constraint
>> - * data struct.
>> - * . a system-wide notification callback using the dev_pm_qos_*_global_notifier
>> - * API. The notification chain data is stored in a static variable.
>> + * Watchers can register a per-device notification callback using the
>> + * dev_pm_qos_*_notifier API. The notification chain data is stored in the
>> + * per-device constraint data struct.
>> *
>> * Note about the per-device constraint data struct allocation:
>> * . The per-device constraints data struct ptr is tored into the device
>> @@ -49,8 +46,6 @@
>> static DEFINE_MUTEX(dev_pm_qos_mtx);
>> static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx);
>>
>> -static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
>> -
>> /**
>> * __dev_pm_qos_flags - Check PM QoS flags for a given device.
>> * @dev: Device to check the PM QoS flags for.
>> @@ -135,8 +130,7 @@ s32 dev_pm_qos_read_value(struct device *dev)
>> * @value: Value to assign to the QoS request.
>> *
>> * Internal function to update the constraints list using the PM QoS core
>> - * code and if needed call the per-device and the global notification
>> - * callbacks
>> + * code and if needed call the per-device callbacks.
>> */
>> static int apply_constraint(struct dev_pm_qos_request *req,
>> enum pm_qos_req_action action, s32 value)
>> @@ -148,12 +142,6 @@ static int apply_constraint(struct dev_pm_qos_request *req,
>> case DEV_PM_QOS_RESUME_LATENCY:
>> ret = pm_qos_update_target(&qos->resume_latency,
>> &req->data.pnode, action, value);
>> - if (ret) {
>> - value = pm_qos_read_value(&qos->resume_latency);
>> - blocking_notifier_call_chain(&dev_pm_notifiers,
>> - (unsigned long)value,
>> - req);
>> - }
>> break;
>> case DEV_PM_QOS_LATENCY_TOLERANCE:
>> ret = pm_qos_update_target(&qos->latency_tolerance,
>> @@ -536,36 +524,6 @@ int dev_pm_qos_remove_notifier(struct device *dev,
>> EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
>>
>> /**
>> - * dev_pm_qos_add_global_notifier - sets notification entry for changes to
>> - * target value of the PM QoS constraints for any device
>> - *
>> - * @notifier: notifier block managed by caller.
>> - *
>> - * Will register the notifier into a notification chain that gets called
>> - * upon changes to the target value for any device.
>> - */
>> -int dev_pm_qos_add_global_notifier(struct notifier_block *notifier)
>> -{
>> - return blocking_notifier_chain_register(&dev_pm_notifiers, notifier);
>> -}
>> -EXPORT_SYMBOL_GPL(dev_pm_qos_add_global_notifier);
>> -
>> -/**
>> - * dev_pm_qos_remove_global_notifier - deletes notification for changes to
>> - * target value of PM QoS constraints for any device
>> - *
>> - * @notifier: notifier block to be removed.
>> - *
>> - * Will remove the notifier from the notification chain that gets called
>> - * upon changes to the target value for any device.
>> - */
>> -int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier)
>> -{
>> - return blocking_notifier_chain_unregister(&dev_pm_notifiers, notifier);
>> -}
>> -EXPORT_SYMBOL_GPL(dev_pm_qos_remove_global_notifier);
>> -
>> -/**
>> * dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor.
>> * @dev: Device whose ancestor to add the request for.
>> * @req: Pointer to the preallocated handle.
>> diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
>> index d4d34791e463..3e2547d6e207 100644
>> --- a/include/linux/pm_qos.h
>> +++ b/include/linux/pm_qos.h
>> @@ -146,8 +146,6 @@ int dev_pm_qos_add_notifier(struct device *dev,
>> struct notifier_block *notifier);
>> int dev_pm_qos_remove_notifier(struct device *dev,
>> struct notifier_block *notifier);
>> -int dev_pm_qos_add_global_notifier(struct notifier_block *notifier);
>> -int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier);
>> void dev_pm_qos_constraints_init(struct device *dev);
>> void dev_pm_qos_constraints_destroy(struct device *dev);
>> int dev_pm_qos_add_ancestor_request(struct device *dev,
>> @@ -199,12 +197,6 @@ static inline int dev_pm_qos_add_notifier(struct device *dev,
>> static inline int dev_pm_qos_remove_notifier(struct device *dev,
>> struct notifier_block *notifier)
>> { return 0; }
>> -static inline int dev_pm_qos_add_global_notifier(
>> - struct notifier_block *notifier)
>> - { return 0; }
>> -static inline int dev_pm_qos_remove_global_notifier(
>> - struct notifier_block *notifier)
>> - { return 0; }
>> static inline void dev_pm_qos_constraints_init(struct device *dev)
>> {
>> dev->power.power_state = PMSG_ON;
>> --
>> 2.7.1.410.g6faf27b
>>