[One (M9) Android Development] Mostafa Wael:
Okay here is what I found out in a nutshell while experimenting with your kernel and latest Slim6 ROM

1- The hotplug: I like that approach actually. Opening apps is noticeably faster compared to stock slim6 kernel's hotplug imo. Also something to note, the stock slim6 kernel is very conservative when it comes to turn the A57 cores back online, hence the slightly less heat when browsing. FYI, HTC by default caps the max freq of the big A57 cores to 1536 MHz while using the phone regularly, and only bumps up the frequency back to 1958 MHz instantaneously when launching apps. I may make the big cluster even more conservative when ramping up, but I a not sure how this will affect the performance.

2- The governors: Zzmoove does not seem to play nicely with my phone, interactive governor with my settings really helps more with the thermals and battery life. A sneak comparison; in an ambient temperature of 28c, while the phone is in its HTC Dot View case, streaming a 1-hr video on YouTube over a 2 Mb/s WiFi connection made it top up to 38-39c and never more. almost all the time it was using freqs under 960 MHz with very rare spikes to 1344 MHz, and like 30% of the time on 600-768 MHz. So that lowered the CPU usage remarkably. Big cluster was kept in check as well.

3- The battery life: I got a 4 hrs 15 minutes SOT over 17 hrs of total usage. There was a lot of music playback as well, so that is a definite green light in my book. Didn't have the chance to compare with stock kernel, but my guess is that it is fractionally better. I used my preset of governor settings and underclocked both clusters to 1344 MHz while using Xposed and Amplify's default limited wakelocks.

4- The verdict: Well, I guess there is no need to say it again, but this kernel pretty much provides a very good experience and a welcome improvement over stock kernel. Good battery life, good performance, thermals has been cured, slightly better app launching and loading, no bugs so far. I would have liked to have some extra time, but sadly I am moving to the OP3 today and as a bit of grim news, my brother is not liking AOSP so I have restored my MaximusHD ROM (the closest to stock ROM) and now I am backing up my data to be transferred.

Thank You very much Dev, and wish you good luck with your project. That discussion of the Hotplug implementation may be worth it for some, perhaps I couldn't extensively test the difference due to the limited timeframe I was put in, but it would be very nice to see either "app dependent" hotplug policy (like turning off the A57 cores while typing for example since we do not need those furious big cores when just typing, but that would be so hard to find/make), a hotplug depending on "overall CPU loads" like when the CPU load crosses 65-70% the A57 cores get "onlined", or a thermal-bound hotplug policy which is pretty much similar to what my thermal mod used to be :)

Other than those suggestions, it will be an out-dated hotplug implementation. And of course do not expect "wonders" with that, just radical differences like 1-3 degrees less maybe, since we are all beating around one bush, the S810 is a hot chip as the cool part -A53 cluster- is not actually "cool" :D

Cheers!