renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-16 17:23:55 +08:00
Code

PM / devfreq: cache the last call to get_dev_status()

Browse Source 
The return value of get_dev_status() can be reused.  Cache it so that
other parts of the kernel can reuse it instead of having to call the
same function again.

Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This commit is contained in:
Javi Merino 2015-08-14 18:56:56 +01:00 committed by MyungJoo Ham
parent 9348da2f1c
commit 08e75e754a
2 changed files with 33 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
drivers/devfreq/governor_simpleondemand.c
View File

@ -21,17 +21,20 @@
static int devfreq_simple_ondemand_func(struct devfreq *df,
unsigned long *freq)
{
struct devfreq_dev_status stat;
int err = df->profile->get_dev_status(df->dev.parent, &stat);
int err;
struct devfreq_dev_status *stat;
unsigned long long a, b;
unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
struct devfreq_simple_ondemand_data *data = df->data;
unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX;
err = devfreq_update_stats(df);
if (err)
return err;
stat = &df->last_status;
if (data) {
if (data->upthreshold)
dfso_upthreshold = data->upthreshold;
@ -43,41 +46,41 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
return -EINVAL;
/* Assume MAX if it is going to be divided by zero */
if (stat.total_time == 0) {
if (stat->total_time == 0) {
*freq = max;
return 0;
}
/* Prevent overflow */
if (stat.busy_time >= (1 << 24) || stat.total_time >= (1 << 24)) {
stat.busy_time >>= 7;
stat.total_time >>= 7;
if (stat->busy_time >= (1 << 24) || stat->total_time >= (1 << 24)) {
stat->busy_time >>= 7;
stat->total_time >>= 7;
}
/* Set MAX if it's busy enough */
if (stat.busy_time * 100 >
stat.total_time * dfso_upthreshold) {
if (stat->busy_time * 100 >
stat->total_time * dfso_upthreshold) {
*freq = max;
return 0;
}
/* Set MAX if we do not know the initial frequency */
if (stat.current_frequency == 0) {
if (stat->current_frequency == 0) {
*freq = max;
return 0;
}
/* Keep the current frequency */
if (stat.busy_time * 100 >
stat.total_time * (dfso_upthreshold - dfso_downdifferential)) {
*freq = stat.current_frequency;
if (stat->busy_time * 100 >
stat->total_time * (dfso_upthreshold - dfso_downdifferential)) {
*freq = stat->current_frequency;
return 0;
}
/* Set the desired frequency based on the load */
a = stat.busy_time;
a *= stat.current_frequency;
b = div_u64(a, stat.total_time);
a = stat->busy_time;
a *= stat->current_frequency;
b = div_u64(a, stat->total_time);
b *= 100;
b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));
*freq = (unsigned long) b;

15
include/linux/devfreq.h
View File

@ -161,6 +161,7 @@ struct devfreq {
struct delayed_work work;
unsigned long previous_freq;
struct devfreq_dev_status last_status;
void *data; /* private data for governors */
@ -204,6 +205,15 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev,
extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq);
/**
* devfreq_update_stats() - update the last_status pointer in struct devfreq
* @df: the devfreq instance whose status needs updating
*/
static inline int devfreq_update_stats(struct devfreq *df)
{
return df->profile->get_dev_status(df->dev.parent, &df->last_status);
}
#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
/**
* struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
@ -289,6 +299,11 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq)
{
}
static inline int devfreq_update_stats(struct devfreq *df)
{
return -EINVAL;
}
#endif /* CONFIG_PM_DEVFREQ */
#endif /* __LINUX_DEVFREQ_H__ */