From: Markus Mayer <[email protected]>
This series lets the user clear the CPUfreq stats by writing to a new
sysfs attribute.
Changes since v1:
- add new cpufreq_freq_attr_wr_perm() macro for write-only
attributes (because this is a separate commit, this patch has
turned into a series)
- remove the Kconfig option, compiling the code unconditionally
- remove show_reset()
- cpufreq_stats_clear_table() takes a struct cpufreq_stats * as
argument rather than a struct cpufreq_policy *
For v1, see https://lkml.org/lkml/2016/11/3/581.
Markus Mayer (2):
cpufreq: add new attribute type cpufreq_freq_attr_wr_perm()
cpufreq: stats: clear statistics
Documentation/cpu-freq/cpufreq-stats.txt | 6 ++++++
drivers/cpufreq/cpufreq_stats.c | 22 ++++++++++++++++++++++
include/linux/cpufreq.h | 4 ++++
3 files changed, 32 insertions(+)
--
2.7.4
From: Markus Mayer <[email protected]>
With the new attribute type, it is possible to create write-only
CPUfreq attributes.
Signed-off-by: Markus Mayer <[email protected]>
---
include/linux/cpufreq.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 5fa55fc..ed09930 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -234,6 +234,10 @@ __ATTR(_name, _perm, show_##_name, NULL)
static struct freq_attr _name = \
__ATTR(_name, 0644, show_##_name, store_##_name)
+#define cpufreq_freq_attr_wr_perm(_name, _perm) \
+static struct freq_attr _name = \
+__ATTR(_name, _perm, NULL, store_##_name)
+
struct global_attr {
struct attribute attr;
ssize_t (*show)(struct kobject *kobj,
--
2.7.4
From: Markus Mayer <[email protected]>
Allow CPUfreq statistics to be cleared by writing anything to
/sys/.../cpufreq/stats/reset.
Signed-off-by: Markus Mayer <[email protected]>
---
Documentation/cpu-freq/cpufreq-stats.txt | 6 ++++++
drivers/cpufreq/cpufreq_stats.c | 22 ++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt
index 8d9773f..3c355f6 100644
--- a/Documentation/cpu-freq/cpufreq-stats.txt
+++ b/Documentation/cpu-freq/cpufreq-stats.txt
@@ -44,11 +44,17 @@ the stats driver insertion.
total 0
drwxr-xr-x 2 root root 0 May 14 16:06 .
drwxr-xr-x 3 root root 0 May 14 15:58 ..
+--w------- 1 root root 4096 May 14 16:06 reset
-r--r--r-- 1 root root 4096 May 14 16:06 time_in_state
-r--r--r-- 1 root root 4096 May 14 16:06 total_trans
-r--r--r-- 1 root root 4096 May 14 16:06 trans_table
--------------------------------------------------------------------------------
+- reset
+Write-only attribute that can be used to reset the stat counters. This can be
+useful for evaluating system behaviour under different governors without the
+need for a reboot.
+
- time_in_state
This gives the amount of time spent in each of the frequencies supported by
this CPU. The cat output will have "<frequency> <time>" pair in each line, which
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 06d3abd..66419e6 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -41,6 +41,18 @@ static int cpufreq_stats_update(struct cpufreq_stats *stats)
return 0;
}
+static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
+{
+ unsigned int count = stats->max_state;
+
+ memset(stats->time_in_state, 0, count * sizeof(u64));
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ memset(stats->trans_table, 0, count * count * sizeof(int));
+#endif
+ stats->last_time = get_jiffies_64();
+ stats->total_trans = 0;
+}
+
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
{
return sprintf(buf, "%d\n", policy->stats->total_trans);
@@ -64,6 +76,14 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
return len;
}
+static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
+ size_t count)
+{
+ /* We don't care what is written to the attribute. */
+ cpufreq_stats_clear_table(policy->stats);
+ return count;
+}
+
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
{
@@ -113,10 +133,12 @@ cpufreq_freq_attr_ro(trans_table);
cpufreq_freq_attr_ro(total_trans);
cpufreq_freq_attr_ro(time_in_state);
+cpufreq_freq_attr_wr_perm(reset, 0200);
static struct attribute *default_attrs[] = {
&total_trans.attr,
&time_in_state.attr,
+ &reset.attr,
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
&trans_table.attr,
#endif
--
2.7.4
On 07-11-16, 10:03, Viresh Kumar wrote:
> On 04-11-16, 09:55, Markus Mayer wrote:
> > From: Markus Mayer <[email protected]>
> >
> > With the new attribute type, it is possible to create write-only
> > CPUfreq attributes.
> >
> > Signed-off-by: Markus Mayer <[email protected]>
> > ---
> > include/linux/cpufreq.h | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> > index 5fa55fc..ed09930 100644
> > --- a/include/linux/cpufreq.h
> > +++ b/include/linux/cpufreq.h
> > @@ -234,6 +234,10 @@ __ATTR(_name, _perm, show_##_name, NULL)
> > static struct freq_attr _name = \
> > __ATTR(_name, 0644, show_##_name, store_##_name)
> >
> > +#define cpufreq_freq_attr_wr_perm(_name, _perm) \
>
> shouldn't this be _wo_perm ?
>
> Also, I wouldn't mind doing this in the second patch itself.
Also there is no need to define a _perm variant here, and then you can avoid
sending 0200 as argument as well.
--
viresh
On 04-11-16, 09:55, Markus Mayer wrote:
> From: Markus Mayer <[email protected]>
>
> Allow CPUfreq statistics to be cleared by writing anything to
> /sys/.../cpufreq/stats/reset.
>
> Signed-off-by: Markus Mayer <[email protected]>
> ---
> Documentation/cpu-freq/cpufreq-stats.txt | 6 ++++++
> drivers/cpufreq/cpufreq_stats.c | 22 ++++++++++++++++++++++
> 2 files changed, 28 insertions(+)
>
> diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt
> index 8d9773f..3c355f6 100644
> --- a/Documentation/cpu-freq/cpufreq-stats.txt
> +++ b/Documentation/cpu-freq/cpufreq-stats.txt
> @@ -44,11 +44,17 @@ the stats driver insertion.
> total 0
> drwxr-xr-x 2 root root 0 May 14 16:06 .
> drwxr-xr-x 3 root root 0 May 14 15:58 ..
> +--w------- 1 root root 4096 May 14 16:06 reset
> -r--r--r-- 1 root root 4096 May 14 16:06 time_in_state
> -r--r--r-- 1 root root 4096 May 14 16:06 total_trans
> -r--r--r-- 1 root root 4096 May 14 16:06 trans_table
> --------------------------------------------------------------------------------
>
> +- reset
> +Write-only attribute that can be used to reset the stat counters. This can be
> +useful for evaluating system behaviour under different governors without the
> +need for a reboot.
> +
> - time_in_state
> This gives the amount of time spent in each of the frequencies supported by
> this CPU. The cat output will have "<frequency> <time>" pair in each line, which
> diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
> index 06d3abd..66419e6 100644
> --- a/drivers/cpufreq/cpufreq_stats.c
> +++ b/drivers/cpufreq/cpufreq_stats.c
> @@ -41,6 +41,18 @@ static int cpufreq_stats_update(struct cpufreq_stats *stats)
> return 0;
> }
>
> +static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
> +{
> + unsigned int count = stats->max_state;
> +
> + memset(stats->time_in_state, 0, count * sizeof(u64));
> +#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
> + memset(stats->trans_table, 0, count * count * sizeof(int));
> +#endif
> + stats->last_time = get_jiffies_64();
> + stats->total_trans = 0;
> +}
> +
> static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
> {
> return sprintf(buf, "%d\n", policy->stats->total_trans);
> @@ -64,6 +76,14 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
> return len;
> }
>
> +static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
> + size_t count)
> +{
> + /* We don't care what is written to the attribute. */
> + cpufreq_stats_clear_table(policy->stats);
> + return count;
> +}
> +
> #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
> static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
> {
> @@ -113,10 +133,12 @@ cpufreq_freq_attr_ro(trans_table);
>
> cpufreq_freq_attr_ro(total_trans);
> cpufreq_freq_attr_ro(time_in_state);
> +cpufreq_freq_attr_wr_perm(reset, 0200);
Just drop the perm argument and this patch looks fine as well.
--
viresh
On 04-11-16, 09:55, Markus Mayer wrote:
> From: Markus Mayer <[email protected]>
>
> With the new attribute type, it is possible to create write-only
> CPUfreq attributes.
>
> Signed-off-by: Markus Mayer <[email protected]>
> ---
> include/linux/cpufreq.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 5fa55fc..ed09930 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -234,6 +234,10 @@ __ATTR(_name, _perm, show_##_name, NULL)
> static struct freq_attr _name = \
> __ATTR(_name, 0644, show_##_name, store_##_name)
>
> +#define cpufreq_freq_attr_wr_perm(_name, _perm) \
shouldn't this be _wo_perm ?
Also, I wouldn't mind doing this in the second patch itself.
> +static struct freq_attr _name = \
> +__ATTR(_name, _perm, NULL, store_##_name)
> +
> struct global_attr {
> struct attribute attr;
> ssize_t (*show)(struct kobject *kobj,
> --
> 2.7.4
--
viresh