Develop Bugs

[Q] Abbreviations

There are many kernel versions. But i don't understand these abbreviations:
2WAY/NO2WAY: ?
BFS: ?
CFS: ?
SVS: ?
HAVS: ?
wifin: ? (wifin-2.6.35.8-snq-111118.zip)
Can anyone define them? Thank you...

2WAY/NO2WAY: it for recording calls, see more here
BFS - Brain F**k Scheduler
The scheduler essentially handles CPU resource allocation. It controls how the CPU ramps up in frequency and down again when not needed. The BFS version is generally very snappy (possibly more so than CFS) but is an older scheduler. It is designed to minimise latency on low spec'd machines (desktops generally)
Further details here:
http://en.wikipedia.org/wiki/Brain_****_Scheduler
CFS - Completely Fair Scheduler
This particular scheduler is newer than BFS. It is designed to make the best of High end machines (desktops again). In the early days, CFS seemed much laggier than BFS but now there is not too much in it. I am quite happily running a modern CFS kernel and I don't experience any lag issues.
Further details here:
SVS - Static Voltage Scaling. HTC's default Kernel is SVS.
Static Voltage Scaling means every CPU frequency uses a set, predefined amount of "power" to sustain that Frequency. The higher the MHz, the higher the mV, meaning the more power is used.
Essentially, SVS uses a table where frequency x = voltage Y
HAVS - Hybrid Adaptive Voltage Scaling
HAVS is is not a set VDD value for each frequency. Rather, it uses a range. This means that frequency x = voltage y-z, depending on a 3rd element - Temperature.
WIFI N= self explanatory

GPU undervolt

Hello,
Just wondering if anyone has experimented with Tegrak Overclock Ultimate's GPU optimization settings. It allows you to undervolt the GPU. Has anyone tried this and is there any benefit to battery life savings with this? I am playing around with the settings right now, so I'll post my results later. So far been able to undervolt the 267 mhz step by -75mv from 1000mv down to 925mv (900mv is unstable for me). And I undervolted the 160 mhz step by -150mv from 900mv down to 750mv. There is also a 200 mhz step I haven't played with. Perhaps keeping the GPU at 200/160 can yield potential battery savings when playing games because games drain the battery so fast.
Hm. I seem to be able to undervolt the 200 mhz step to 750mv as well. I'm going to run a 200/160 gpu setup at 750mv and see if I can save any battery playing Gun Bros and will let you guys know.

caaznkid said:
There is also a 200 mhz step I haven't played with. \
Click to expand...
Click to collapse
Really? I only have the 267 and 160 MHz clock settings available. Any thoughts anyone?
Oh, I have underclocked my GPU settings but only by a modest 25mV each.

There's only 2 steps, but u can change the clock between 160, 200, and 267

yep ... good results
Yep I've been experimenting with GPU undervolting and had some sucess. So I was methodically working downwards and testing stability... then i saw this thread and thought what the hell, right? I shot for lowest mv of 750 and it's rock solid at 200mhz.
Can confirm 750mv stable at 100, 134, 160 and 200mhz. 267mhz can't be undervolted that much.
I've locked 200mhz 750mz for both speed steps and left it at that. Phone has yet to display any instability in a couple of days of mixed use including gaming. Battery life better? Subjectively yes, mostly I notice phone doesn't get so hot playing Dead Space.
Power consumption scales down almost linearly with clock cycles, and exponentially with voltage (right?). So by my math GPU is using about 40% of the power it does at full 267mhz. I wonder what the TDP of the exynos 4210 is and how much the Mali 400 contributes to that, would give some idea of what battery life to expect. Since GPU sits idle a lot, I doubt it's a magic fix.
Such is the power of our phones I have to underclock the CPU and GPU quite far before any 3D game gets too choppy to play. 160mhz is more than fine for most.
Usually undervolting makes the most sense for power saving because a given computing workload takes a certain number of cpu cycles. But 3D usually tries to render as many frames as it can, with the exception of S2's 60fps frame cap. So slowing down the GPU to no more than you need might improve gaming battery life?
My SGS2 is a bit sensitive to undervolting although underclocking of CPU, so I'm happy be able to so agressively undervolt the GPU.
I'd be interested to know who else can just set 200mhz & 750mv and have it rock solid? If not, 200/800 or 160/750?

I've rarely had problems when I use Tegrak. Then again, I undervolt 100mv on my cpu between 200-1000mhz, and about 50mv on my GPU at 267mhz with the noop scheduler and tweaks enabled. If I can get Tegrak to work with the Gunslinger kernel (currently causes reboot loops when I load the overclock module), I'll report back on battery life with Tegrak and experiment a little more.

jyaworski said:
I've rarely had problems when I use Tegrak. Then again, I undervolt 100mv on my cpu between 200-1000mhz, and about 50mv on my GPU at 267mhz with the noop scheduler and tweaks enabled. If I can get Tegrak to work with the Gunslinger kernel (currently causes reboot loops when I load the overclock module), I'll report back on battery life with Tegrak and experiment a little more.
Click to expand...
Click to collapse
I had the same problem with Gunslinger, I decided to keep my phone on Rogue Stock EL29.
I've been able to drop my GPU Level 0 Clock to 160mhz and voltage to 850mv with out any issues.
I also keep my GPU 1 Clock at 100mhz and my voltage at 750mv without a problem.
Using noop of course.
Changing GPU clocks and volts doesn't help much.
Keeping your CPU Internal Voltage and Core Voltage -50mV and keeping it scaled 200-800 MHz will give you much better battery.

I think the effect would be more significant in ICS since ICS use GPU to render UI

CPU Governers?

What's the difference between / features of:
Interactive
Conservative
Ondemand
Smartass
Smartassv2
Performance (is it run at the maximum?)
Powersave (is it run at the minimum?)
And does performance for each vary per kernel? What I mean is will, say, Interactive be better than Conservative on Incredikernel AOSP but worse on Tiny GB Sense?

pianoplayer said:
What's the difference between / features of:
Interactive
Conservative
Ondemand
Smartass
Smartassv2
Performance (is it run at the maximum?)
Powersave (is it run at the minimum?)
And does performance for each vary per kernel? What I mean is will, say, Interactive be better than Conservative on Incredikernel AOSP but worse on Tiny GB Sense?
Click to expand...
Click to collapse
ondemand
Available in most kernels, and the default governor in most kernels. When the CPU load reaches a certain point (see "up threshold" in Advanced Settings), ondemand will rapidly scale the CPU up to meet demand, then gradually scale the CPU down when it isn't needed. - SetCPU website
conservative
Available in some kernels. It is similar to the ondemand governor, but will scale the CPU up more gradually to better fit demand. Conservative provides a less responsive experience than ondemand, but can save battery. - SetCPU website
performance
Available in most kernels. It will keep the CPU running at the "max" set value at all times. This is a bit more efficient than simply setting "max" and "min" to the same value and using ondemand because the system will not waste resources scanning for the CPU load. This governor is recommended for stable benchmarking. - SetCPU website
powersave
Available in some kernels. It will keep the CPU running at the "min" set value at all times. - SetCPU website
userspace
A method for controlling the CPU speed that isn't currently used by SetCPU. For best results, do not use the userspace governor. - SetCPU website
Interactive
The 'interactive' governor has a different approach. Instead of sampling the cpu at a specified rate, the governor will scale the cpu frequency up when coming out of idle. When the cpu comes out of idle, a timer is configured to fire within 1-2 ticks. If the cpu is 100% busy from exiting idle to when the timer fires then we assume the cpu is underpowered and ramp to MAX speed.
If the cpu was not 100% busy, then the governor evaluates the cpu load over the last 'min_sample_rate' (default 50000 uS) to determine the cpu speed to ramp down to.
SMARTASS GOVERNOR
Based on the concept of the interactive governor. I have always agreed that in theory the way interactive works - by taking over the idle loop - is very attractive. I have never managed to tweak it so it would behave decently in real life. Smartass is a complete rewrite of the code plus more. I think its a success. Performance is on par with the "old" minmax and I think smartass is a bit more responsive. Battery life is hard to quantify precisely but it does spend much more time at the lower frequencies. Smartass will also cap the max frequency when sleeping to 245Mhz (or if your min frequency is higher than 245 - why?! - it will cap it to your min frequency). Lets take for example the 998/245 kernel, it will sleep at 245. No need for sleep profiles any more!
The performance for each can varry by kernel due to the fact that some devs slightly tweak the governors to their liking. Without any tweaking they should be the same accross all kernels.
Also note that tinys kernel has an interactive X governor and also a smartass 2 governor. These are basicky just tweaked versions of the original governor.

pianoplayer said:
What's the difference between / features of:
Interactive
Conservative
Ondemand
Smartass
Smartassv2
Performance (is it run at the maximum?)
Powersave (is it run at the minimum?)
And does performance for each vary per kernel? What I mean is will, say, Interactive be better than Conservative on Incredikernel AOSP but worse on Tiny GB Sense?
Click to expand...
Click to collapse
This is a good resource for governors. It is quite technical though. It doesn't include smartass though smartass is similar to smartassv2.
CPU Governors
Let me know if you still have questions after reading it.
The answer to your second question is no. The build of the governors are about 95% the same between kernels and with the exception of the smartass governors all those listed are stock android kernels.
Interactive should be smoother than conservative or ondemand but similar in performance to the smartass governors.
SmartassV2 is found to give the best performance/battery life combo across the board.
Edit: Good writeup cmlusco. In practice yes, smartassv2 is better all around I think. Interactive from Nexus S/Galaxy Nexus kernel source should be good but I've yet to be able to backport it to work on this phone property. It turns into a performance governor really.
And a side note. If the phone is actually in deep sleep state (reported by CPU Spy) the governor will not really matter then. Only time screen off matters is when it's awake but screen is off. Governor is most critical when screen is on really, so if you go for performance, screen on performance is what matters.
Edit 2: And I read some interesting viewpoints recently on maximizing battery that are different than the minimize CPU speed.

[Q] How large of an impact does OCing have on battery?

Right now I'm at 1.35GHz with Francos stock settings, so 700 for the minimum. Should I expect to see much of a loss in battery life? And what is the difference between the different governors? I could never find much info about them.

The OC itself dosent affect battery, it's how much time your phone is in whatever state(350, 700, 1350, etc..) also setting the minimum to 700 is either really good or really bad for battery, if you turn on your screen ever 5 minutes then it will be better to have it at 700 but if you only turn on your screen once every couple hours you will get much better battery with the absolute minimum. As for governors
Code:
interactive - Instead of sampling the cpu at a specified rate, the governor will scale the cpu frequency up when coming out of idle. When the cpu comes out of idle, a timer is configured to fire within 1-2 ticks. If the cpu is 100% busy from exiting idle to when the timer fires then we assume the cpu is underpowered and ramp to MAX speed.
smartass - Is an improved version of interactive governor
ondemand – Available in most kernels, and the default governor in most kernels. When the CPU load reaches a certain point (see “up threshold” in Advanced Settings), ondemand will rapidly scale the CPU up to meet demand, then gradually scale the CPU down when it isn't needed.
conservative – Available in some kernels. It is similar to the ondemand governor, but will scale the CPU up more gradually to better fit demand. Conservative provides a less responsive experience than ondemand, but can save battery.
performance – Available in most kernels. It will keep the CPU running at the “max” set value at all times. This is a bit more efficient than simply setting “max” and “min” to the same value and using ondemand because the system will not waste resources scanning for CPU load.
powersave – Available in some kernels. It will keep the CPU running at the “min” set value at all times.
userspace – A method for controlling the CPU speed that isn't currently used by SetCPU. For best results, do not use the userspace governor.
brazilianwax - Very agresive version of smartass
interactiveX - Tweaked Interactive governor by Imoseyon by adding more features like suspend/wake profile
ondemandX - Tweaked and ported from 2.6.38 base Ondemand governor by Imoseyon by adding more features like suspend/wake profile
This is taken from the lord module kernel from the desire HD forum as it has a list of many governors, you may have to try a couple governors until you find one that balances speed and battery life for your personal needs, on more governor on our devices is hotplug which will turn off one of the CPU cores when the screen is off.

Best kernel for D851 Fulmics 6.1! Your opinion!

If u are using the fulmics 6.1 which is your best kernel so far for this rom???
Is it better than fulmics stock kernel??
Pros and Cons???

Solid Kernel is really smooth (you will see a significant difference overall and in antutu 3d section). If you leave the settings as is, however, it will drain the battery quickly and you will get around 3 hours sot with moderate usage(throughout a day). I use the following kernel aduitor settings and they make a difference without compromising too much in my experience.
!(Backup system partition in twrp before modifying anything)!
Assertive display: On if mostly indoors, off if mostly outdoors
Cpu: Max freq.=2457 Min freq.=300 Input boost=1497
Hotplug: Idle freq.=1574 MinCpuOnline=2 Multicore power savings=enabled (aggressive causes heating)
Cpu Voltage: (undervolt) -100mv for lowest 3 freqs, -50mv for highest 3, -75mv for all between those
Thermal: Set limit for 70 degree celcius
Gpu: governor= msm adreno tz, Gpumin=200, adreno idler on, idlewait=3, set all other sliders in the middle for other idler settings. (Adjust few steps based on your experience) also you can use 300mhz gpu min freq for buttery smooth performance.
!All those are based on personal experience so it is possible that this condiguration may not work for you!