On Tue, Nov 17, 2009 at 06:06:56PM -0700, Ai Li wrote:
> Date: Tue, 17 Nov 2009 18:06:56 -0700
> From: Ai Li <aili@xxxxxxxxxxxxxx>
> To: mgross@xxxxxxxxxxxxxxx
> Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
> Subject: Re: adding handles to pm_qos?
>
> > Thanks, I'll look at it over the next few days.
> >
> > --mgross
> >
> > > Here is the patch that I use with the test code. There are
> > three new
> > > functions:
> > >
> > > void *pm_qos_get(int qos, char *name);
> > > int pm_qos_put(void *handle);
> > > int pm_qos_update_requirement_direct(void *handle, s32
> > new_value);
> > >
> > > In the test, I wanted to keep the existing interface intact so
> > I
> > > could compare them at the same time. For the formal code
> > submission,
> > > a different approach may work better.
>
>
> Here is an alternate way of adding handles to pm_qos_params that I
> was alluding to. This approach may be more preferable because it
> does not bloat the API and the handles become an integral part of
> pm_qos_params. In my previous patch, handles are kind of bolted onto
> pm_qos_params and it needs separate calls (pm_qos_get, pm_qos_put) to
> acquire and release the handle. In this patch,
> pm_qos_add_requirement and pm_qos_remove_requirement automatically
> take care of the handles.
>
>
> --- include/linux/pm_qos_params.h.orig
> +++ include/linux/pm_qos_params.h
> @@ -14,9 +14,11 @@
> #define PM_QOS_NUM_CLASSES 4
> #define PM_QOS_DEFAULT_VALUE -1
>
> -int pm_qos_add_requirement(int qos, char *name, s32 value);
> -int pm_qos_update_requirement(int qos, char *name, s32 new_value);
> -void pm_qos_remove_requirement(int qos, char *name);
> +struct requirement_list;
> +
> +struct requirement_list *pm_qos_add_requirement(int qos, char *name,
> s32 value);
> +int pm_qos_update_requirement(struct requirement_list *qos, s32
> new_value);
> +void pm_qos_remove_requirement(struct requirement_list *qos);
>
> int pm_qos_requirement(int qos);
>
> --- kernel/pm_qos_params.c.orig
> +++ kernel/pm_qos_params.c
> @@ -49,6 +49,7 @@
> */
> struct requirement_list {
> struct list_head list;
> + int pm_qos_class;
> union {
> s32 value;
> s32 usec;
> @@ -207,13 +208,16 @@ EXPORT_SYMBOL_GPL(pm_qos_requirement);
> * performance characteristics. It recomputes the aggregate QoS
> expectations
> * for the pm_qos_class of parameters.
> */
> -int pm_qos_add_requirement(int pm_qos_class, char *name, s32 value)
> +struct requirement_list *pm_qos_add_requirement(int pm_qos_class,
> char *name,
looks like your email client buggered the your patch.
mgross@mgross-laptop:~/marks/Linux/linux-2.6$ patch -p0 < /home/mgross/pm_qos_handle.patch
patching file include/linux/pm_qos_params.h
patch: **** malformed patch at line 43: s32 value);
Please resend
--mgross
> + s32 value)
> {
> struct requirement_list *dep;
> unsigned long flags;
>
> dep = kzalloc(sizeof(struct requirement_list), GFP_KERNEL);
> if (dep) {
> + dep->pm_qos_class = pm_qos_class;
> +
> if (value == PM_QOS_DEFAULT_VALUE)
> dep->value =
> pm_qos_array[pm_qos_class]->default_value;
> else
> @@ -228,48 +232,37 @@ int pm_qos_add_requirement(int pm_qos_class,
> char *name, s32 value)
> spin_unlock_irqrestore(&pm_qos_lock, flags);
> update_target(pm_qos_class);
>
> - return 0;
> + return dep;
> }
>
> cleanup:
> kfree(dep);
> - return -ENOMEM;
> + return ERR_PTR(-ENOMEM);
> }
> EXPORT_SYMBOL_GPL(pm_qos_add_requirement);
>
> /**
> * pm_qos_update_requirement - modifies an existing qos request
> - * @pm_qos_class: identifies which list of qos request to us
> - * @name: identifies the request
> + * @qos: identifies the qos request to us
> * @value: defines the qos request
> *
> - * Updates an existing qos requirement for the pm_qos_class of
> parameters along
> + * Updates an existing qos requirement along
> * with updating the target pm_qos_class value.
> - *
> - * If the named request isn't in the list then no change is made.
> */
> -int pm_qos_update_requirement(int pm_qos_class, char *name, s32
> new_value)
> +int pm_qos_update_requirement(struct requirement_list *qos, s32
> new_value)
> {
> unsigned long flags;
> - struct requirement_list *node;
> int pending_update = 0;
>
> spin_lock_irqsave(&pm_qos_lock, flags);
> - list_for_each_entry(node,
> - &pm_qos_array[pm_qos_class]->requirements.list, list)
> {
> - if (strcmp(node->name, name) == 0) {
> - if (new_value == PM_QOS_DEFAULT_VALUE)
> - node->value =
> -
> pm_qos_array[pm_qos_class]->default_value;
> - else
> - node->value = new_value;
> - pending_update = 1;
> - break;
> - }
> - }
> + if (new_value == PM_QOS_DEFAULT_VALUE)
> + qos->value =
> pm_qos_array[qos->pm_qos_class]->default_value;
> + else
> + qos->value = new_value;
> + pending_update = 1;
> spin_unlock_irqrestore(&pm_qos_lock, flags);
> if (pending_update)
> - update_target(pm_qos_class);
> + update_target(qos->pm_qos_class);
>
> return 0;
> }
> @@ -277,32 +270,26 @@ EXPORT_SYMBOL_GPL(pm_qos_update_requirement);
>
> /**
> * pm_qos_remove_requirement - modifies an existing qos request
> - * @pm_qos_class: identifies which list of qos request to us
> + * @qos: identifies the qos request to us
> * @name: identifies the request
> *
> - * Will remove named qos request from pm_qos_class list of
> parameters and
> + * Will remove qos request from pm_qos_class list and
> * recompute the current target value for the pm_qos_class.
> */
> -void pm_qos_remove_requirement(int pm_qos_class, char *name)
> +void pm_qos_remove_requirement(struct requirement_list *qos)
> {
> unsigned long flags;
> - struct requirement_list *node;
> int pending_update = 0;
>
> spin_lock_irqsave(&pm_qos_lock, flags);
> - list_for_each_entry(node,
> - &pm_qos_array[pm_qos_class]->requirements.list, list)
> {
> - if (strcmp(node->name, name) == 0) {
> - kfree(node->name);
> - list_del(&node->list);
> - kfree(node);
> - pending_update = 1;
> - break;
> - }
> - }
> + list_del(&qos->list);
> + pending_update = 1;
> spin_unlock_irqrestore(&pm_qos_lock, flags);
> if (pending_update)
> - update_target(pm_qos_class);
> + update_target(qos->pm_qos_class);
> +
> + kfree(qos->name);
> + kfree(qos);
> }
> EXPORT_SYMBOL_GPL(pm_qos_remove_requirement);
>
> @@ -345,37 +332,42 @@ int pm_qos_remove_notifier(int pm_qos_class,
> struct notifier_block *notifier)
> EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
>
> #define PID_NAME_LEN sizeof("process_1234567890")
> -static char name[PID_NAME_LEN];
>
> static int pm_qos_power_open(struct inode *inode, struct file *filp)
> {
> int ret;
> long pm_qos_class;
> + char name[PID_NAME_LEN];
> + struct requirement_list *qos;
>
> lock_kernel();
> pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
> - if (pm_qos_class >= 0) {
> - filp->private_data = (void *)pm_qos_class;
> - sprintf(name, "process_%d", current->pid);
> - ret = pm_qos_add_requirement(pm_qos_class, name,
> - PM_QOS_DEFAULT_VALUE);
> - if (ret >= 0) {
> - unlock_kernel();
> - return 0;
> - }
> + if (pm_qos_class < 0) {
> + ret = -EPERM;
> + goto power_open_exit;
> }
> - unlock_kernel();
>
> - return -EPERM;
> + sprintf(name, "process_%d", current->pid);
> + qos = pm_qos_add_requirement(pm_qos_class, name,
> PM_QOS_DEFAULT_VALUE);
> + if (IS_ERR(qos)) {
> + ret = PTR_ERR(qos);
> + goto power_open_exit;
> + }
> +
> + filp->private_data = qos;
> + ret = 0;
> +
> +power_open_exit:
> + unlock_kernel();
> + return ret;
> }
>
> static int pm_qos_power_release(struct inode *inode, struct file
> *filp)
> {
> - int pm_qos_class;
> + struct requirement_list *qos;
>
> - pm_qos_class = (long)filp->private_data;
> - sprintf(name, "process_%d", current->pid);
> - pm_qos_remove_requirement(pm_qos_class, name);
> + qos = (struct requirement_list *)filp->private_data;
> + pm_qos_remove_requirement(qos);
>
> return 0;
> }
> @@ -384,15 +376,15 @@ static ssize_t pm_qos_power_write(struct file
> *filp, const char __user *buf,
> size_t count, loff_t *f_pos)
> {
> s32 value;
> - int pm_qos_class;
> + struct requirement_list *qos;
>
> - pm_qos_class = (long)filp->private_data;
> if (count != sizeof(s32))
> return -EINVAL;
> if (copy_from_user(&value, buf, sizeof(s32)))
> return -EFAULT;
> - sprintf(name, "process_%d", current->pid);
> - pm_qos_update_requirement(pm_qos_class, name, value);
> +
> + qos = (struct requirement_list *)filp->private_data;
> + pm_qos_update_requirement(qos, value);
>
> return sizeof(s32);
> }
>
>
> ~Ai
>
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> linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
> https://lists.linux-foundation.org/mailman/listinfo/linux-pm
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