Further to the above (experimental) script, I've just taken it out on the road for a few hours, to see whether I've done the overall performance any good. Results are mixed... the good news is that I haven't produced a single crash and that the impact on battery life (whilst not yet measured) is (subjectively) acceptable.

The impact on performance/responsiveness is the mixed bag; once the overclocking happens, I can really tell the difference between Opera running at 1100 and Opera running at 805 or 900. However, it can take a couple of seconds to surpass the up_threshold and increase the clock speed, so it shows the benefit more when it's rendering the first web pages loaded than while bringing up Opera itself. I could solve that by temporarily locking a frequency, but that would guarantee to waste more power on every unlock, whether it turns out to be needed or not.

From watching conky while playing with commonly used applications, I've seen quite a lot of the CPU hitting 50-60% usage (at 500MHz) for a while before it triggering the desired speed boost. OK, the system may not be CPU-bound at that point, but two or three seconds later we hit the up_threshold. This makes me tempted either to lower the up_threshold and make our hair trigger even finer, or to keep it at 75 but lower the minimum speed to 250MHz. My intention is that merely unlocking the phone (such as to check the time) should not do any more than it has to (staying at minimum speed would be nice), but that unlocking the phone and e.g. starting Opera should trigger 1100MHz before I ask it even to give me the start page.

Again, I don't warrant that this is either clever or desirable, but I'm having fun. Comments or refinements welcomed...

Try custom menu shortcuts

Ya create a script that will launch the commad that's its arg and modify the .desktop files

Try custom menu shortcuts

Ya create a script that will launch the commad that's its arg and modify the .desktop files

Hrm... this sounds like it is potentially useful, but the problem with any desktop "toggle" switch is that I have to remember to use it.

I did consider the idea of replacing specific shortcuts (such as Opera) with scripts that would set appropriate values and then launch the application, so that it remains a one-step process, but I found several reasons not to do that:

1) I'd have to do this per application, in order not to add additional steps of launching a script and selecting an app. Would be a PITA to maintain.

2) I don't have an event-driven method of detecting the closure of that application, so I'd still have to rely on either DBUS, a timer or looping with pgrep to revert any temporary settings I made.

3) This being the case, and provided that the ondemand frequency governor lets me achieve sane behaviour, it makes sense (to me at least) to preempt the CPU demand by assuming that when I unlock the phone, it will normally be to load or switch an application, so within reason, overclock by default.

Thanks for the thought, though.

If there was a governor with multiple values, e.g. 250,600,805,950