Explain the implications of suggested tweaks

[Scott Wegner]

Binary package hint: powertop

Powertop seems to be a very useful tool for analyzing power usage and suggesting easy system tweaks to decrease power use. However, it is a little dangerous in that root-level system tweaks are only a hot-key away, with no real explanation of what's going on.

I think it would be useful if powertop also offered a short explanation of what each of the suggested tweaks would do, and give any specific warning. Some examples:
-- I saw one suggestion on my system that recommended that I disable HAL polling my cdrom. That's fine for now, but what if I insert a CD later? Will I be able to use the CD? Will this setting revert at reboot?
-- There was another suggestion that I increase the dirty writeback interval from 0.30 seconds to 15 seconds. This should send a warning to the user, that this can cause high risk of data corruption in a power outage.

[jjos (jbenjos)]

PowerTop can be a little more clear on what drawbacks, if any, there are is in a given action.

[Scott Wegner (swegner)]

Although perhaps beyond the scope of the utility, it may also be useful to have a history of actions taken, and also the option to "undo" a given tweak. This would require backing-up the previous value as well.

[Virgil Brummond (uraharakisuke153)]

I agree with the "undo" ability, though I believe most tweaks are not permanent and revert on reboot. Also, I think it would be nice if we had a Power Initive where us as a community puts forward a bit of effort and logs into improving power management. This would be good for open source as a whole.

[Christoph Buchner (bilderbuchi)]

I agree, this needs more information.
On one machine I have ~15 bad tunables, but I don't dare to switch on most of them, because I have no idea about the (negative) consequences, what I could break (or if the changes are harmless), if they revert on boot, what kind of power savings they bring (maybe difficult to predict, or how to get back if they break the system.