Re: [PATCH v4] PM / devfreq: add clearing transitions stats

From: Chanwoo Choi
Date: Thu Dec 05 2019 - 21:13:31 EST


On 12/6/19 11:18 AM, Chanwoo Choi wrote:
> From: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>
>
> Add clearing transition table and time in states devfreq statistics
> by writing 0 (zero) to trans_stat file in devfreq sysfs. An example use
> is like following:
>
> echo 0 > /sys/class/devfreq/devfreqX/trans_stat
>
> Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>
> [cw00.choi: Edit return value if entering the wrong value for reset
> and use arrary3_size() to get the size of 3-dimensional array]
> Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-class-devfreq | 11 ++++---
> drivers/devfreq/devfreq.c | 29 ++++++++++++++++++-
> 2 files changed, 35 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq
> index 75897e2fde43..9758eb85ade3 100644
> --- a/Documentation/ABI/testing/sysfs-class-devfreq
> +++ b/Documentation/ABI/testing/sysfs-class-devfreq
> @@ -55,12 +55,15 @@ What: /sys/class/devfreq/.../trans_stat
> Date: October 2012
> Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
> Description:
> - This ABI shows the statistics of devfreq behavior on a
> - specific device. It shows the time spent in each state and
> - the number of transitions between states.
> + This ABI shows or clears the statistics of devfreq behavior
> + on a specific device. It shows the time spent in each state
> + and the number of transitions between states.
> In order to activate this ABI, the devfreq target device
> driver should provide the list of available frequencies
> - with its profile.
> + with its profile. If need to reset the statistics of devfreq
> + behavior on a specific device, enter 0(zero) to 'trans_stat'
> + as following:
> + echo 0 > /sys/class/devfreq/.../trans_stat
>
> What: /sys/class/devfreq/.../userspace/set_freq
> Date: September 2011
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index abecadeb3dc2..df31f430051d 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -1478,7 +1478,34 @@ static ssize_t trans_stat_show(struct device *dev,
> devfreq->total_trans);
> return len;
> }
> -static DEVICE_ATTR_RO(trans_stat);
> +
> +static ssize_t trans_stat_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct devfreq *df = to_devfreq(dev);
> + int err, value;
> +
> + if (df->profile->max_state == 0)
> + return count;
> +
> + err = kstrtoint(buf, 10, &value);
> + if (err || value != 0)
> + return -EINVAL;
> +
> + mutex_lock(&df->lock);
> + memset(df->time_in_state, 0, (df->profile->max_state *
> + sizeof(*df->time_in_state)));
> + memset(df->trans_table, 0, array3_size(sizeof(unsigned int),
> + df->profile->max_state,
> + df->profile->max_state));
> + df->total_trans = 0;
> + df->last_stat_updated = get_jiffies_64();
> + mutex_unlock(&df->lock);
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(trans_stat);
>
> static struct attribute *devfreq_attrs[] = {
> &dev_attr_name.attr,
>

Applied it. Thanks.

--
Best Regards,
Chanwoo Choi
Samsung Electronics