lkml.org 
[lkml]   [2009]   [Oct]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[v8 PATCH 2/8]: cpuidle: implement a list based approach to register a set of idle routines.
    * Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-10-08 15:18:28]:

    Implement a list based registering mechanism for architectures which
    have multiple sets of idle routines which are to be registered.

    Currently, in x86 it is done by merely setting pm_idle = idle_routine
    and managing this pm_idle pointer is messy.

    To give an example of how this mechanism works:
    In x86, initially, idle routine is selected from the set of poll/mwait/
    c1e/default idle loops. So the selected idle loop is registered in cpuidle
    as one idle state cpuidle devices. Once ACPI comes up, it registers
    another set of idle states on top of this state. Again, suppose a module
    registers another set of idle loops, it is added to this list.

    This provides a clean way of registering and unregistering idle state
    routines.

    In the current implementation, pm_idle is set as the current idle routine
    being used and the old idle routine has to be maintained and when a module
    registers/unregisters an idle routine, confusion arises.


    Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
    ---
    drivers/cpuidle/cpuidle.c | 54 ++++++++++++++++++++++++++++++++++++++++------
    include/linux/cpuidle.h | 1
    2 files changed, 48 insertions(+), 7 deletions(-)

    Index: linux.trees.git/drivers/cpuidle/cpuidle.c
    ===================================================================
    --- linux.trees.git.orig/drivers/cpuidle/cpuidle.c
    +++ linux.trees.git/drivers/cpuidle/cpuidle.c
    @@ -22,6 +22,7 @@
    #include "cpuidle.h"

    DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
    +DEFINE_PER_CPU(struct list_head, cpuidle_devices_list);

    DEFINE_MUTEX(cpuidle_lock);

    @@ -112,6 +113,45 @@ void cpuidle_resume_and_unlock(void)

    EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);

    +int cpuidle_add_to_list(struct cpuidle_device *dev)
    +{
    + int ret, cpu = dev->cpu;
    + struct cpuidle_device *old_dev;
    +
    + if (!list_empty(&per_cpu(cpuidle_devices_list, cpu))) {
    + old_dev = list_first_entry(&per_cpu(cpuidle_devices_list, cpu),
    + struct cpuidle_device, idle_list);
    + cpuidle_remove_state_sysfs(old_dev);
    + }
    +
    + list_add(&dev->idle_list, &per_cpu(cpuidle_devices_list, cpu));
    + ret = cpuidle_add_state_sysfs(dev);
    + return ret;
    +}
    +
    +void cpuidle_remove_from_list(struct cpuidle_device *dev)
    +{
    + struct cpuidle_device *temp_dev;
    + struct list_head *pos;
    + int ret, cpu = dev->cpu;
    +
    + list_for_each(pos, &per_cpu(cpuidle_devices_list, cpu)) {
    + temp_dev = container_of(pos, struct cpuidle_device, idle_list);
    + if (dev == temp_dev) {
    + list_del(&temp_dev->idle_list);
    + cpuidle_remove_state_sysfs(temp_dev);
    + break;
    + }
    + }
    +
    + if (!list_empty(&per_cpu(cpuidle_devices_list, cpu))) {
    + temp_dev = list_first_entry(&per_cpu(cpuidle_devices_list, cpu),
    + struct cpuidle_device, idle_list);
    + ret = cpuidle_add_state_sysfs(temp_dev);
    + }
    + cpuidle_kick_cpus();
    +}
    +
    /**
    * cpuidle_enable_device - enables idle PM for a CPU
    * @dev: the CPU
    @@ -136,9 +176,6 @@ int cpuidle_enable_device(struct cpuidle
    return ret;
    }

    - if ((ret = cpuidle_add_state_sysfs(dev)))
    - return ret;
    -
    if (cpuidle_curr_governor->enable &&
    (ret = cpuidle_curr_governor->enable(dev)))
    goto fail_sysfs;
    @@ -157,7 +194,7 @@ int cpuidle_enable_device(struct cpuidle
    return 0;

    fail_sysfs:
    - cpuidle_remove_state_sysfs(dev);
    + cpuidle_remove_from_list(dev);

    return ret;
    }
    @@ -182,8 +219,6 @@ void cpuidle_disable_device(struct cpuid

    if (cpuidle_curr_governor->disable)
    cpuidle_curr_governor->disable(dev);
    -
    - cpuidle_remove_state_sysfs(dev);
    }

    EXPORT_SYMBOL_GPL(cpuidle_disable_device);
    @@ -267,6 +302,7 @@ int cpuidle_register_device(struct cpuid
    }

    cpuidle_enable_device(dev);
    + cpuidle_add_to_list(dev);

    mutex_unlock(&cpuidle_lock);

    @@ -288,6 +324,7 @@ void cpuidle_unregister_device(struct cp
    cpuidle_pause_and_lock();

    cpuidle_disable_device(dev);
    + cpuidle_remove_from_list(dev);

    per_cpu(cpuidle_devices, dev->cpu) = NULL;

    @@ -338,12 +375,15 @@ static inline void latency_notifier_init
    */
    static int __init cpuidle_init(void)
    {
    - int ret;
    + int ret, cpu;

    ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
    if (ret)
    return ret;

    + for_each_possible_cpu(cpu)
    + INIT_LIST_HEAD(&per_cpu(cpuidle_devices_list, cpu));
    +
    latency_notifier_init(&cpuidle_latency_notifier);

    return 0;
    Index: linux.trees.git/include/linux/cpuidle.h
    ===================================================================
    --- linux.trees.git.orig/include/linux/cpuidle.h
    +++ linux.trees.git/include/linux/cpuidle.h
    @@ -92,6 +92,7 @@ struct cpuidle_device {
    struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
    struct cpuidle_state *last_state;

    + struct list_head idle_list;
    struct kobject kobj;
    struct completion kobj_unregister;
    void *governor_data;

    \
     
     \ /
      Last update: 2009-10-08 11:59    [W:0.042 / U:0.756 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site