Re: [linux-pm] [RFC PATCH] thermal: Add support to report coolingstatistics achieved by cooling devices

From: Amit Kachhap
Date: Mon Feb 06 2012 - 18:16:17 EST

On 6 February 2012 09:03, Greg KH <greg@xxxxxxxxx> wrote:
> On Mon, Feb 06, 2012 at 05:56:58PM +0100, Pavel Machek wrote:
>> Hi!
>> > Add a sysfs node code to report effective cooling of all cooling devices
>> > attached to each trip points of a thermal zone. The cooling data reported
>> > will be absolute if the higher temperature trip points are arranged first
>> > otherwise the cooling stats is the cumulative effect of the earlier
>> > invoked cooling handlers.
>> >
>> > The basic assumption is that cooling devices will bring down the temperature
>> > in a symmetric manner and those statistics can be stored back and used for
>> > further tuning of the system.
>> /sys fs should be one-value-per-file, talk to gregkh.
> That's correct.
> Why not use debugfs for this instead?
> thanks,
> greg k-h

Thanks Greg/Pavel for looking into the patch.
Basically I checked the places where single sysfs entry is showing
more then 1 output. And
1) /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
2) /sys/devices/system/cpu/cpu0/cpufreq/stats/trans_table
are the places where the output is more than 1 value.

Anyway I can enclose this sysfs inside CONFIG_THERMAL_COOLING_STATS macro.

Amit Daniel
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