Re: [RESEND][PATCH] cpufreq: stats: Add 'load_table' sysfs file toshow accumulated data of CPU

From: Chanwoo Choi
Date: Thu Jun 13 2013 - 22:11:55 EST


On 06/12/2013 08:05 PM, Rafael J. Wysocki wrote:
> On Wednesday, June 12, 2013 09:32:16 AM Viresh Kumar wrote:
>> On 12 June 2013 03:44, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
>>> On Wednesday, June 05, 2013 05:11:22 PM Chanwoo Choi wrote:
>>>> This patch add new sysfs file to show previous accumulated data of CPU load
>>>> as following path. This sysfs file is used to judge the correct system state
>>>> or determine suitable system resource on user-space.
>>>> - /sys/devices/system/cpu/cpu0/cpufreq/stats/load_table
>>>>
>>>> This sysfs file include following data:
>>>> - Measurement point of time
>>>> - CPU frequency
>>>> - Per-CPU load
>>>>
>>>> Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
>>>> Signed-off-by: Myungjoo Ham <myungjoo.ham@xxxxxxxxxxx>
>>>> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
>>>
>>> Well, first of all, there is the "one value per file" rule for sysfs attributes
>>> which is evidently violated by this code.
>>
>> Even this was enclosed in CONFIG_CPU_FREQ_STAT_DETAILS,
>> so even sysfs isn't that bad as we already had something similar here.
>
> Yes, we did, and yes, it was a mistake. It should have been in debugfs from
> the very beginning.
>
>>> Second, this looks like a feature needed to handle one particular platform, so
>>> why do you want to add it to the cpufreq core?
>>
>> I really felt this would be useful to others. They can track the load on
>> all cores for some time and that will really be useful. People can
>> understand their loads and system more easily with this patch in.
>
> If it were in debugfs, I'd have no objections.
>

OK, I will reimplement load_table node by using debugfs instead of sysfs.

Thanks.

Best Regards,
Chanwoo Choi


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