Re: [PATCH 17/21] cpuidle: avoid unnecessary kzalloc/free of struct cpuidle_driver_kobj

On 09/22/2013 03:21 AM, Viresh Kumar wrote:

For CONFIG_CPU_IDLE_MULTIPLE_DRIVERS, struct cpuidle_device always needs to allocate struct cpuidle_driver_kobj for all CPUs and so there is no real need to have a pointer to it inside struct cpuidle_device.

This patch makes a object instance of struct cpuidle_driver_kobj inside struct cpuidle_device instead of a pointer.

It also makes kobj_driver dependent on CONFIG_CPU_IDLE_MULTIPLE_DRIVERS.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org

Comment similar to patch 16/21. If you try to offline/online a cpu, that should lead to a kernel warning.

---

drivers/cpuidle/sysfs.c | 20 +++----------------- include/linux/cpuidle.h | 11 +++++++++-- 2 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index db0aac3..3386d64 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -439,12 +439,6 @@ static void cpuidle_remove_state_sysfs(struct cpuidle_device *device) static struct cpuidle_driver_attr attr_driver_##_name = \ __ATTR(_name, 0644, show, NULL) -struct cpuidle_driver_kobj {

• struct cpuidle_driver *drv;
• struct completion kobj_unregister;
• struct kobject kobj;

-};

struct cpuidle_driver_attr { struct attribute attr; ssize_t (*show)(struct cpuidle_driver *, char *); @@ -518,27 +512,20 @@ static struct kobj_type ktype_driver_cpuidle = { */ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev) {

• struct cpuidle_driver_kobj *kdrv;

• struct cpuidle_driver_kobj *kdrv = &dev->kobj_driver; struct cpuidle_device_kobj *kdev = &dev->kobj_dev; struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); int ret;

• kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
• if (!kdrv)

• return -ENOMEM;
  

• kdrv->drv = drv; init_completion(&kdrv->kobj_unregister);

ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle, &kdev->kobj, "driver");

• if (ret) {

• kfree(kdrv);
  

• if (ret) return ret;

• }

kobject_uevent(&kdrv->kobj, KOBJ_ADD);

• dev->kobj_driver = kdrv;

return ret; } @@ -549,10 +536,9 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev) */ static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev) {

• struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;

• struct cpuidle_driver_kobj *kdrv = &dev->kobj_driver; kobject_put(&kdrv->kobj); wait_for_completion(&kdrv->kobj_unregister);

• kfree(kdrv);

} #else static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev) diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 1fc5cb5..0f0da17 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -62,7 +62,6 @@ struct cpuidle_state { #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) struct cpuidle_state_kobj; -struct cpuidle_driver_kobj; struct cpuidle_device_kobj { struct cpuidle_device *dev; @@ -70,6 +69,12 @@ struct cpuidle_device_kobj { struct kobject kobj; }; +struct cpuidle_driver_kobj {

• struct cpuidle_driver *drv;
• struct completion kobj_unregister;
• struct kobject kobj;

+};

struct cpuidle_device { unsigned int registered:1; unsigned int enabled:1; @@ -79,7 +84,9 @@ struct cpuidle_device { int state_count; struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];

• struct cpuidle_driver_kobj *kobj_driver;

+#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS

• struct cpuidle_driver_kobj kobj_driver;

+#endif struct cpuidle_device_kobj kobj_dev; struct list_head device_list;