Da uno scambio di messaggi intercorso tra il sottoscritto e Alexander Clouter, l'autore di questo nuovo governor, e da una mia richiesta di documentazione (questo in quanto non è ancora inclusa, teniamo presente che i kernel che la implementano per adesso sono in fase "rc", e questa feature è appena passata dalla fase di patch a feature vera e propria inserita nel kernel), vi copio quanto Alex mi ha inviato per settare (o spiegare) i valori che si trovano nei file inlcusi nella directory /sys/devices/system/cpu/.../cpufreq/conservative/:



ignore_nice:
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Takes a value of zero or one. _If set to '0' (default) then all processes are counted towards towards 'cpu utilisation', if set to '1' then processes that are 'nice'd[1] will not count to the overal usage.

So if you are running an intensive calculation on your laptop which is not nice'd then your cpu speed will increase steadily upwards. _If you have nice'd the process then your cpu speed will say fixed and only rise when non-nice'd processes require more power.

freq_step:
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This describes what steps the cpu freq should be increased/decreased by when it needs to. _By default the cpu speed will increase in 5% chunks of your maximum cpu speed. _You can change this value to anywhere between 0 and 100;
'0' will effectively lock your CPU at a speed regardless of its load and
'100' will make it behave identically to the cpufreq_ondemand module (in theory

The options that are available to both 'ondemand' and 'conservative' are:

sampling_rate:
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Measured in uS (10^-6 seconds). _This is how often you want the kernel to look at the cpu usage and make a decision on whether to increase or decrease the cpu speed. _Typically set to values of around '10000'.

'show_sampling_rate_max' and 'show_sampling_rate_min':
------------------------------------------------------
The minimum and maximum sampling rates available to you to set 'sampling_rate' to.

'up_threshold' and 'down_threshold':
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Defines what the average cpu usaged between the samplings of 'sampling_rate' should we increase/decrease the cpu. _For example when 'up_threshold' is 80 (default) it means that between checking the cpu needs to be on average more
that 80% in use to decide the CPU speed needs to be increased. _For 'down_threshold' if 20 (default) it means that if the CPU usage is *below* 20% between samples then the cpu speed is decreased.

sampling_down_factor:
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Usually about '5' and simply controls the rate at which the cpu speed is decreased, it means that 5 times a decision to slow down the machine have to occur in a row before the cpu speed is actually dropped. _If set to '1' then the speed decreases as quickly as in increases, if set to two the decrease occurs at half the rate of the increase.

[1] I do not know if you know but 'nice' means the priority of of the process, >0 means its got a lower priority, <0 means its got a high priority.
When a process is 'nice'd it means its got a nice value of more than one.

Una nota di ringraziamento ad Alex che si è dimostrato veramente veloce e disponibile nel rispondere.

Chiunque decidesse di usare questo nuovo governor può poi ritrovarsi in questo thread dove ci possiamo scambiare le impressioni, sopratutto sul risparmio energetico che dovrebbe portare nei portatili.