* [PATCH] cpufreq: stats: Use lock by stat to replace global spin lock
@ 2019-03-25 7:29 Kyle Lin
2019-03-26 18:43 ` Matthias Kaehlcke
0 siblings, 1 reply; 4+ messages in thread
From: Kyle Lin @ 2019-03-25 7:29 UTC (permalink / raw)
To: Rafael J . Wysocki, Viresh Kumar; +Cc: linux-pm, linux-kernel, linkyle0915
Stats is updated by each policy, using the lock by stat can
reduce the contention.
Signed-off-by: Kyle Lin <linkyle0915@gmail.com>
---
drivers/cpufreq/cpufreq_stats.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index e2db5581489a..17beb1bc7e16 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -14,7 +14,6 @@
#include <linux/module.h>
#include <linux/slab.h>
-static DEFINE_SPINLOCK(cpufreq_stats_lock);
struct cpufreq_stats {
unsigned int total_trans;
@@ -23,6 +22,7 @@ struct cpufreq_stats {
unsigned int state_num;
unsigned int last_index;
u64 *time_in_state;
+ spinlock_t lock; /*spinlock for stats update*/
unsigned int *freq_table;
unsigned int *trans_table;
};
@@ -39,12 +39,12 @@ static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
{
unsigned int count = stats->max_state;
- spin_lock(&cpufreq_stats_lock);
+ spin_lock(&stats->lock);
memset(stats->time_in_state, 0, count * sizeof(u64));
memset(stats->trans_table, 0, count * count * sizeof(int));
stats->last_time = get_jiffies_64();
stats->total_trans = 0;
- spin_unlock(&cpufreq_stats_lock);
+ spin_unlock(&stats->lock);
}
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
@@ -62,9 +62,9 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
if (policy->fast_switch_enabled)
return 0;
- spin_lock(&cpufreq_stats_lock);
+ spin_lock(&stats->lock);
cpufreq_stats_update(stats);
- spin_unlock(&cpufreq_stats_lock);
+ spin_unlock(&stats->lock);
for (i = 0; i < stats->state_num; i++) {
len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
@@ -211,6 +211,7 @@ void cpufreq_stats_create_table(struct cpufreq_policy *policy)
stats->state_num = i;
stats->last_time = get_jiffies_64();
stats->last_index = freq_table_get_index(stats, policy->cur);
+ spin_lock_init(&stats->lock);
policy->stats = stats;
ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
@@ -242,11 +243,11 @@ void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
if (old_index == -1 || new_index == -1 || old_index == new_index)
return;
- spin_lock(&cpufreq_stats_lock);
+ spin_lock(&stats->lock);
cpufreq_stats_update(stats);
stats->last_index = new_index;
stats->trans_table[old_index * stats->max_state + new_index]++;
stats->total_trans++;
- spin_unlock(&cpufreq_stats_lock);
+ spin_unlock(&stats->lock);
}
--
2.21.0.392.gf8f6787159e-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] cpufreq: stats: Use lock by stat to replace global spin lock
2019-03-25 7:29 [PATCH] cpufreq: stats: Use lock by stat to replace global spin lock Kyle Lin
@ 2019-03-26 18:43 ` Matthias Kaehlcke
2019-04-08 5:39 ` Viresh Kumar
0 siblings, 1 reply; 4+ messages in thread
From: Matthias Kaehlcke @ 2019-03-26 18:43 UTC (permalink / raw)
To: Kyle Lin; +Cc: Rafael J . Wysocki, Viresh Kumar, linux-pm, linux-kernel
On Mon, Mar 25, 2019 at 03:29:33PM +0800, Kyle Lin wrote:
> Stats is updated by each policy, using the lock by stat can
> reduce the contention.
>
> Signed-off-by: Kyle Lin <linkyle0915@gmail.com>
> ---
> drivers/cpufreq/cpufreq_stats.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
> index e2db5581489a..17beb1bc7e16 100644
> --- a/drivers/cpufreq/cpufreq_stats.c
> +++ b/drivers/cpufreq/cpufreq_stats.c
> @@ -14,7 +14,6 @@
> #include <linux/module.h>
> #include <linux/slab.h>
>
> -static DEFINE_SPINLOCK(cpufreq_stats_lock);
>
> struct cpufreq_stats {
> unsigned int total_trans;
> @@ -23,6 +22,7 @@ struct cpufreq_stats {
> unsigned int state_num;
> unsigned int last_index;
> u64 *time_in_state;
> + spinlock_t lock; /*spinlock for stats update*/
nit: not sure if the comment adds much value. If it stay there it
needs a blank after '/*' and another before '*/'
> unsigned int *freq_table;
> unsigned int *trans_table;
> };
> @@ -39,12 +39,12 @@ static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
> {
> unsigned int count = stats->max_state;
>
> - spin_lock(&cpufreq_stats_lock);
> + spin_lock(&stats->lock);
> memset(stats->time_in_state, 0, count * sizeof(u64));
> memset(stats->trans_table, 0, count * count * sizeof(int));
> stats->last_time = get_jiffies_64();
> stats->total_trans = 0;
> - spin_unlock(&cpufreq_stats_lock);
> + spin_unlock(&stats->lock);
> }
>
> static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
> @@ -62,9 +62,9 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
> if (policy->fast_switch_enabled)
> return 0;
>
> - spin_lock(&cpufreq_stats_lock);
> + spin_lock(&stats->lock);
> cpufreq_stats_update(stats);
> - spin_unlock(&cpufreq_stats_lock);
> + spin_unlock(&stats->lock);
>
> for (i = 0; i < stats->state_num; i++) {
> len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
> @@ -211,6 +211,7 @@ void cpufreq_stats_create_table(struct cpufreq_policy *policy)
> stats->state_num = i;
> stats->last_time = get_jiffies_64();
> stats->last_index = freq_table_get_index(stats, policy->cur);
> + spin_lock_init(&stats->lock);
>
> policy->stats = stats;
> ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
> @@ -242,11 +243,11 @@ void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
> if (old_index == -1 || new_index == -1 || old_index == new_index)
> return;
>
> - spin_lock(&cpufreq_stats_lock);
> + spin_lock(&stats->lock);
> cpufreq_stats_update(stats);
>
> stats->last_index = new_index;
> stats->trans_table[old_index * stats->max_state + new_index]++;
> stats->total_trans++;
> - spin_unlock(&cpufreq_stats_lock);
> + spin_unlock(&stats->lock);
> }
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cpufreq: stats: Use lock by stat to replace global spin lock
2019-03-26 18:43 ` Matthias Kaehlcke
@ 2019-04-08 5:39 ` Viresh Kumar
2019-04-08 5:39 ` Viresh Kumar
0 siblings, 1 reply; 4+ messages in thread
From: Viresh Kumar @ 2019-04-08 5:39 UTC (permalink / raw)
To: Matthias Kaehlcke; +Cc: Kyle Lin, Rafael J . Wysocki, linux-pm, linux-kernel
On 26-03-19, 11:43, Matthias Kaehlcke wrote:
> On Mon, Mar 25, 2019 at 03:29:33PM +0800, Kyle Lin wrote:
> > Stats is updated by each policy, using the lock by stat can
> > reduce the contention.
> >
> > Signed-off-by: Kyle Lin <linkyle0915@gmail.com>
> > ---
> > drivers/cpufreq/cpufreq_stats.c | 15 ++++++++-------
> > 1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
> > index e2db5581489a..17beb1bc7e16 100644
> > --- a/drivers/cpufreq/cpufreq_stats.c
> > +++ b/drivers/cpufreq/cpufreq_stats.c
> > @@ -14,7 +14,6 @@
> > #include <linux/module.h>
> > #include <linux/slab.h>
> >
> > -static DEFINE_SPINLOCK(cpufreq_stats_lock);
> >
> > struct cpufreq_stats {
> > unsigned int total_trans;
> > @@ -23,6 +22,7 @@ struct cpufreq_stats {
> > unsigned int state_num;
> > unsigned int last_index;
> > u64 *time_in_state;
> > + spinlock_t lock; /*spinlock for stats update*/
>
> nit: not sure if the comment adds much value. If it stay there it
> needs a blank after '/*' and another before '*/'
Just drop the comment please.
--
viresh
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cpufreq: stats: Use lock by stat to replace global spin lock
2019-04-08 5:39 ` Viresh Kumar
@ 2019-04-08 5:39 ` Viresh Kumar
0 siblings, 0 replies; 4+ messages in thread
From: Viresh Kumar @ 2019-04-08 5:39 UTC (permalink / raw)
To: Matthias Kaehlcke; +Cc: Kyle Lin, Rafael J . Wysocki, linux-pm, linux-kernel
On 26-03-19, 11:43, Matthias Kaehlcke wrote:
> On Mon, Mar 25, 2019 at 03:29:33PM +0800, Kyle Lin wrote:
> > Stats is updated by each policy, using the lock by stat can
> > reduce the contention.
> >
> > Signed-off-by: Kyle Lin <linkyle0915@gmail.com>
> > ---
> > drivers/cpufreq/cpufreq_stats.c | 15 ++++++++-------
> > 1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
> > index e2db5581489a..17beb1bc7e16 100644
> > --- a/drivers/cpufreq/cpufreq_stats.c
> > +++ b/drivers/cpufreq/cpufreq_stats.c
> > @@ -14,7 +14,6 @@
> > #include <linux/module.h>
> > #include <linux/slab.h>
> >
> > -static DEFINE_SPINLOCK(cpufreq_stats_lock);
> >
> > struct cpufreq_stats {
> > unsigned int total_trans;
> > @@ -23,6 +22,7 @@ struct cpufreq_stats {
> > unsigned int state_num;
> > unsigned int last_index;
> > u64 *time_in_state;
> > + spinlock_t lock; /*spinlock for stats update*/
>
> nit: not sure if the comment adds much value. If it stay there it
> needs a blank after '/*' and another before '*/'
Just drop the comment please.
--
viresh
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-04-08 5:39 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2019-03-25 7:29 [PATCH] cpufreq: stats: Use lock by stat to replace global spin lock Kyle Lin
2019-03-26 18:43 ` Matthias Kaehlcke
2019-04-08 5:39 ` Viresh Kumar
2019-04-08 5:39 ` Viresh Kumar
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