Originally Posted by Timmmmaaahh
Read this useful post by the OP:
The governor is the profile you select that will manage a great number of kernel related values, hotplugging can be a part of it. Someone smarter than me will correct that if I'm not (entirely) right ^_^
That post pretty much sums it all up.
Before the SoC's (complete boards with everything integrated a.k.a your phones motherboard; ex. Qualcomm Snapdragon, Kirin, OMAP, Samsung Exynos) got so efficient people were disabling some of the cores to save power.
But, since the new ones are way more efficient, switching on and off uses more power than leaving it on and so its not done (it became pointless/inefficient saving electricity that way) - hence hotplugging is removed.
Hotplug was (only) switching cores off and back on, governor sets variables and system settings and so on. In the beginning they were separate pieces of code, later (the mentioned X versions) built the hotplugging logic into the kernel (more efficient code-wise and less error-prone because it could be tailored to a specific kernel/device) .
---------- Post added at 10:42 PM ---------- Previous post was at 10:19 PM ----------
Originally Posted by XDADoog
Question (from a noob):
Does anyone know if there´s an option or a rom that has kinda like a built-in option to change governors? not the settings, just the governor per se; something like an option on the battery setting to select a governor, then reboot and work with that governor? (not dealing with the option, just changing the governor on the next reboot.
Also, what is more efficient: to go through each frequency or to go to pre-selected frequency?
I think that; battery wise; a pre-selected frequency would be faster but don´t know if would be efficient regarding the workload.
Use apps to change govs - you fed root for that.
When the system boots the default settings are used, then, when the app runs it sets the changes (usually after a set and adjustable time out).
When devs create their custom kernels they usually test out various settings and scenarios and will set up the one that works for THEM best (they know very well what and how to test, usually comes down to best user experience unless they state the aim specifically, like say gaming).
They can also set up profiles (purely a set of settings). This if course will become the default that is set while booting the device.
Device vendors aren't spending much time to optimise (read test different sets of settings as it is too time consuming and so foookin expensive) so they'll go with time proven settings and governors, because 'it works best for most average users' and thus creates the least overhead on support departments (and they are right in many ways). Also makes selling new phones easier (newer must be better right?).
Every chip is and behaves different, you can spend endless time searching for the best settings and still not find it. I
Unless you have an older chip (like 3+ wars old) or a castrated (low(er) performance versions of the top end) one, there isn't much of a gain in tweaking it. Just thought you should know. So my answer for your last question is that lots of people spent lots of time debating and proving both, but it all depends (how would you know what freq should be preselected?)