Database Develop

Gpu governors explain?

Can someone explain the first three and the last two gpu governors in Franco kernel? I don't know what they are. Also, which gpu governor is best for performance and battery? Thanks.
Sent from my Nexus 6 using XDA Free mobile app

For the governors, you can find explanations of the governors by searching on Google.
Also you're using FauxClock with Franco Kernel which does not ensure compatibility as Franco Kernel's app does not expose GPU Governors.
Also, which gpu governor is best for performance and battery? Thanks.
Click to expand...
Click to collapse
Read the governors, theres one for "powersave" and one for "performance"
Personally I'd recommend using whatever is default and just underclock the GPU and use Per-App-Modes in Franco's app to clock the GPU higher in apps/games that require it.

Here is some info I found by searching the forum posted by another member. I take no credit for this post because I did not write it:
Thanks to deedii for posting this in another forum:
http://forum.xda-developers.com/show...65&postcount=2
Android CPU governors explained
1: OnDemand
2: OndemandX
3: Performance
4: Powersave
5: Conservative
6: Userspace
7: Min Max
8: Interactive
9: InteractiveX
10: Smartass
11: SmartassV2
12: Scary
13: Lagfree
14: Smoothass
15: Brazilianwax
16: SavagedZen
17: Lazy
18: Lionheart
19: LionheartX
20: Intellidemand
21: Hotplug
22: BadAss
23: Wheatley
24: Lulzactive
25: Pegasusq/Pegasusd
26: hotplugx
27: AbissPlug
28: MSM DCVS
29: IntelliActive
30: Adaptive
31: Nightmare
32: ZZmove
INFO I/O Scheduler go here: SCHEDULER
1: OnDemand Governor:
This governor has a hair trigger for boosting clockspeed to the maximum speed set by the user. If the CPU load placed by the user abates, the OnDemand governor will slowly step back down through the kernel's frequency steppings until it settles at the lowest possible frequency, or the user executes another task to demand a ramp.
OnDemand has excellent interface fluidity because of its high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand is commonly chosen by smartphone manufacturers because it is well-tested, reliable, and virtually guarantees the smoothest possible performance for the phone. This is so because users are vastly more likely to ***** about performance than they are the few hours of extra battery life another governor could have granted them.
This final fact is important to know before you read about the Interactive governor: OnDemand scales its clockspeed in a work queue context. In other words, once the task that triggered the clockspeed ramp is finished, OnDemand will attempt to move the clockspeed back to minimum. If the user executes another task that triggers OnDemand's ramp, the clockspeed will bounce from minimum to maximum. This can happen especially frequently if the user is multi-tasking. This, too, has negative implications for battery life.
2: OndemandX:
Basically an ondemand with suspend/wake profiles. This governor is supposed to be a battery friendly ondemand. When screen is off, max frequency is capped at 500 mhz. Even though ondemand is the default governor in many kernel and is considered safe/stable, the support for ondemand/ondemandX depends on CPU capability to do fast frequency switching which are very low latency frequency transitions. I have read somewhere that the performance of ondemand/ondemandx were significantly varying for different i/o schedulers. This is not true for most of the other governors. I personally feel ondemand/ondemandx goes best with SIO I/O scheduler.
3: Performance Governor:
This locks the phone's CPU at maximum frequency. While this may sound like an ugly idea, there is growing evidence to suggest that running a phone at its maximum frequency at all times will allow a faster race-to-idle. Race-to-idle is the process by which a phone completes a given task, such as syncing email, and returns the CPU to the extremely efficient low-power state. This still requires extensive testing, and a kernel that properly implements a given CPU's C-states (low power states).
4: Powersave Governor:
The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.
5:Conservative Governor:
This biases the phone to prefer the lowest possible clockspeed as often as possible. In other words, a larger and more persistent load must be placed on the CPU before the conservative governor will be prompted to raise the CPU clockspeed. Depending on how the developer has implemented this governor, and the minimum clockspeed chosen by the user, the conservative governor can introduce choppy performance. On the other hand, it can be good for battery life.
The Conservative Governor is also frequently described as a "slow OnDemand," if that helps to give you a more complete picture of its functionality.
6: Userspace Governor:
This governor, exceptionally rare for the world of mobile devices, allows any program executed by the user to set the CPU's operating frequency. This governor is more common amongst servers or desktop PCs where an application (like a power profile app) needs privileges to set the CPU clockspeed.
7: Min Max
well this governor makes use of only min & maximum frequency based on workload... no intermediate frequencies are used.
8: Interactive Governor:
Much like the OnDemand governor, the Interactive governor dynamically scales CPU clockspeed in response to the workload placed on the CPU by the user. This is where the similarities end. Interactive is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.
Unlike OnDemand, which you'll recall scales clockspeed in the context of a work queue, Interactive scales the clockspeed over the course of a timer set arbitrarily by the kernel developer. In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. This can eliminate the frequency bouncing discussed in the OnDemand section. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. This is another pro-battery life benefit of Interactive.
However, because Interactive is permitted to spend more time at maximum frequency than OnDemand (for device performance reasons), the battery-saving benefits discussed above are effectively negated. Long story short, Interactive offers better performance than OnDemand (some say the best performance of any governor) and negligibly different battery life.
Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above.
9: InteractiveX Governor:
Created by kernel developer "Imoseyon," the InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to better balance battery vs. performance. The InteractiveX governor's defining feature, however, is that it locks the CPU frequency to the user's lowest defined speed when the screen is off.
10: Smartass
Is 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 352Mhz (or if your min frequency is higher than 352 – why?! – it will cap it to your min frequency). Lets take for example the 528/176 kernel, it will sleep at 352/176. No need for sleep profiles any more!"
11: SmartassV2:
Version 2 of the original smartass governor from Erasmux. Another favorite for many a people. The governor aim for an "ideal frequency", and ramp up more aggressively towards this freq and less aggressive after. It uses different ideal frequencies for screen on and screen off, namely awake_ideal_freq and sleep_ideal_freq. This governor scales down CPU very fast (to hit sleep_ideal_freq soon) while screen is off and scales up rapidly to awake_ideal_freq (500 mhz for GS2 by default) when screen is on. There's no upper limit for frequency while screen is off (unlike Smartass). So the entire frequency range is available for the governor to use during screen-on and screen-off state. The motto of this governor is a balance between performance and battery.
12: Scary
A new governor wrote based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It will give the same performance as conservative right now, it will get tweaked over time.
13: Lagfree:
Lagfree is similar to ondemand. Main difference is it's optimization to become more battery friendly. Frequency is gracefully decreased and increased, unlike ondemand which jumps to 100% too often. Lagfree does not skip any frequency step while scaling up or down. Remember that if there's a requirement for sudden burst of power, lagfree can not satisfy that since it has to raise cpu through each higher frequency step from current. Some users report that video playback using lagfree stutters a little.
14: Smoothass:
The same as the Smartass “governor” But MUCH more aggressive & across the board this one has a better battery life that is about a third better than stock KERNEL
15: Brazilianwax:
Similar to smartassV2. More aggressive ramping, so more performance, less battery
16: SavagedZen:
Another smartassV2 based governor. Achieves good balance between performance & battery as compared to brazilianwax.
17: Lazy:
This governor from Ezekeel is basically an ondemand with an additional parameter min_time_state to specify the minimum time CPU stays on a frequency before scaling up/down. The Idea here is to eliminate any instabilities caused by fast frequency switching by ondemand. Lazy governor polls more often than ondemand, but changes frequency only after completing min_time_state on a step overriding sampling interval. Lazy also has a screenoff_maxfreq parameter which when enabled will cause the governor to always select the maximum frequency while the screen is off.
18: Lionheart:
Lionheart is a conservative-based governor which is based on samsung's update3 source.
The tunables (such as the thresholds and sampling rate) were changed so the governor behaves more like the performance one, at the cost of battery as the scaling is very aggressive.
19: LionheartX
LionheartX is based on Lionheart but has a few changes on the tunables and features a suspend profile based on Smartass governor.
20: Intellidemand:
Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. Unlike what some users believe, this governor is not the replacement for OC Daemon (Having different governors for sleep and awake). The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode. We can see some 'traces' of interactive governor here. Frequency scale-up decision is made based on idling time of CPU. Lower idling time (<20%) causes CPU to scale-up from current frequency. Frequency scale-down happens at steps=5% of max frequency. (This parameter is tunable only in conservative, among the popular governors)
To sum up, this is an intelligent ondemand that enters browsing mode to limit max frequency when GPU is idling, and (exits browsing mode) behaves like ondemand when GPU is busy; to deliver performance for gaming and such. Intellidemand does not jump to highest frequency when screen is off.
21: Hotplug Governor:
The Hotplug governor performs very similarly to the OnDemand governor, with the added benefit of being more precise about how it steps down through the kernel's frequency table as the governor measures the user's CPU load. However, the Hotplug governor's defining feature is its ability to turn unused CPU cores off during periods of low CPU utilization. This is known as "hotplugging."
22: BadAss Governor:
Badass removes all of this "fast peaking" to the max frequency. On a typical system the cpu won't go above 918Mhz and therefore stay cool and will use less power. To trigger a frequency increase, the system must run a bit @ 918Mhz with high load, then the frequency is bumped to 1188Mhz. If that is still not enough the governor gives you full throttle. (this transition should not take longer than 1-2 seconds, depending on the load your system is experiencing)
Badass will also take the gpu load into consideration. If the gpu is moderately busy it will bypass the above check and clock the cpu with 1188Mhz. If the gpu is crushed under load, badass will lift the restrictions to the cpu.
23: Wheatley:
Building on the classic 'ondemand' governor is implemented Wheatley governor. The governor has two additional parameters:
target_residency - The minimum average residency in µs which is considered acceptable for a proper efficient usage of the C4 state. Default is 10000 = 10ms.
allowed_misses - The number sampling intervals in a row the average residency is allowed to be lower than target_residency before the governor reduces the frequency. This ensures that the governor is not too aggressive in scaling down the frequency and reduces it just because some background process was temporarily causing a larger number of wakeups. The default is 5.
Wheatley works as planned and does not hinder the proper C4 usage for task where the C4 can be used properly .
For internet browsing the time spend in C4 has increased by 10% points and the average residency has increased by about 1ms. I guess these differences are mostly due to the different browsing behaviour (I spend the last time more multi-tabbing). But at least we can say that Wheatley does not interfere with the proper use of the C4 state during 'light' tasks. For music playback with screen off the time spend in C4 is practically unchanged, however the average residency is reduced from around 30ms to around 18ms, but this is still more than acceptable.
So the results show that Wheatley works as intended and ensures that the C4 state is used whenever the task allows a proper efficient usage of the C4 state. For more demanding tasks which cause a large number of wakeups and prevent the efficient usage of the C4 state, the governor resorts to the next best power saving mechanism and scales down the frequency. So with the new highly-flexible Wheatley governor one can have the best of both worlds.
Obviously, this governor is only available on multi-core devices.
24: Lulzactive:
Lulzactive:
This new find from Tegrak is based on Interactive & Smartass governors and is one of the favorites.
Old Version: When workload is greater than or equal to 60%, the governor scales up CPU to next higher step. When workload is less than 60%, governor scales down CPU to next lower step. When screen is off, frequency is locked to global scaling minimum frequency.
New Version: Three more user configurable parameters: inc_cpu_load, pump_up_step, pump_down_step. Unlike older version, this one gives more control for the user. We can set the threshold at which governor decides to scale up/down. We can also set number of frequency steps to be skipped while polling up and down.
When workload greater than or equal to inc_cpu_load, governor scales CPU pump_up_step steps up. When workload is less than inc_cpu_load, governor scales CPU down pump_down_step steps down.
Example:
Consider
inc_cpu_load=70
pump_up_step=2
pump_down_step=1
If current frequency=200, Every up_sampling_time Us if cpu load >= 70%, cpu is scaled up 2 steps - to 800.
If current frequency =1200, Every down_sampling_time Us if cpu load < 70%, cpu is scaled down 1 step - to 1000.
25: Pegasusq/Pegasusd
The Pegasus-q / d is a multi-core based on the Ondemand governor and governor with integrated hot-plugging.
Ongoing processes in the queue, we know that multiple processes can run simultaneously on. These processes are active in an array, which is a field called "Run Queue" queue that is ongoing, with their priority values arranged (priority will be used by the task scheduler, which then decides which process to run next).
To ensure that each process has its fair share of resources, each running for a certain period and will eventually stop and then again placed in the queue until it is your turn again. If a program is terminated, so that others can run the program with the highest priority in the current queue is executed.
26: hotplugx
It 'a Hotplug modified and optimized for the suspension in off-screen
27: AbissPlug
It 'a Governor derived hotplug, it works the same way, but with the changes in savings for a better battery.
28: MSM DCVS
a very efficient and wide range of Dynamic Clock and
Voltage Scaling (DCVS) which addresses usage models from
active standby to mid and high level processing requirements.
A Krait CPU can smoothly scale from low power, low
leakage mode to blazingly fast performance.
Believe it's a governor that is mfg'd by qualcomm to utilize new on chip features.
MSM is the prefix for the SOC (MSM8960) and DCVS is Dynamic Clock and Voltage Scaling. Makes sense, MSM-DCVS
29: IntelliActive
Based off Google's Interactive governor with the following enhancements:
1. self-boost capability from input drivers (no need for PowerHAL assist)
2. two phase scheduling (idle/busy phases to prevent from jumping directly to max freq
3. Checks for offline cpus and short circuits some unnecessary checks to improve code execution paths
30: Adaptive
This driver adds a dynamic cpufreq policy governor
designed for latency-sensitive workloads and also for demanding
performance.
This governor attempts to reduce the latency of clock
increases so that the system is more responsive to
interactive workloads in loweset steady-state but to
to reduce power consumption in middle operation level level up
will be done in step by step to prohibit system from going to
max operation level.
31: Nightmare
A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery.
In addition to the SoD is a prevention because it usually does not hotplug.
32: ZZmove
ZZmove Governor optimized for low power consumption with the screen off, with particular attention to the limitation of consumption applications in the background with the screen off, such as listening to music. It has three settings: battery saver, balanced and performance. In addition to a performance boost, there is also the governor zzmove optimized.
Credits goes to:
http://icrontic.com/discussion/95140...m-tuner-tegrak
http://forum.xda-developers.com/show....php?t=1369817
I/O SCHEDULERS
Q. "What purposes does an i/o scheduler serve?" A.
• Minimize hard disk seek latency.
• Prioritize I/O requests from processes.
• Allocate disk bandwidth for running processes.
• Guarantee that certain requests will be served before a deadline.
So in the simplest of simplest form: Kernel controls the disk access using I/O Scheduler.
Q. "What goals every I/O scheduler tries to balance?" A.
• Fairness (let every process have its share of the access to disk)
• Performance (try to serve requests close to current disk head position first, because seeking there is fastest)
• Real-time (guarantee that a request is serviced in a given time)
Q. "Description, advantages, disadvantages of each I/O Scheduler?" A.
1) Noop
Inserts all the incoming I/O requests to a First In First Out queue and implements request merging. Best used with storage devices that does not depend on mechanical movement to access data (yes, like our flash drives). Advantage here is that flash drives does not require reordering of multiple I/O requests unlike in normal hard drives.
Advantages:
• Serves I/O requests with least number of cpu cycles. (Battery friendly?)
• Best for flash drives since there is no seeking penalty.
• Good throughput on db systems.
Disadvantages:
• Reduction in number of cpu cycles used is proportional to drop in performance.
2) Deadline
Goal is to minimize I/O latency or starvation of a request. The same is achieved by round robin policy to be fair among multiple I/O requests. Five queues are aggressively used to reorder incoming requests.
Advantages:
• Nearly a real time scheduler.
• Excels in reducing latency of any given single I/O.
• Best scheduler for database access and queries.
• Bandwidth requirement of a process - what percentage of CPU it needs, is easily calculated.
• Like noop, a good scheduler for solid state/flash drives.
Disadvantages:
• When system is overloaded, set of processes that may miss deadline is largely unpredictable.
3) CFQ
Completely Fair Queuing scheduler maintains a scalable per-process I/O queue and attempts to distribute the available I/O bandwidth equally among all I/O requests. Each per-process queue contains synchronous requests from processes. Time slice allocated for each queue depends on the priority of the 'parent' process. V2 of CFQ has some fixes which solves process' i/o starvation and some small backward seeks in the hope of improving responsiveness.
Advantages:
• Considered to deliver a balanced i/o performance.
• Easiest to tune.
• Excels on multiprocessor systems.
• Best database system performance after deadline.
Disadvantages:
• Some users report media scanning takes longest to complete using CFQ. This could be because of the property that since the bandwidth is equally distributed to all i/o operations during boot-up, media scanning is not given any special priority.
• Jitter (worst-case-delay) exhibited can sometimes be high, because of the number of tasks competing for the disk.
4) BFQ
Instead of time slices allocation by CFQ, BFQ assigns budgets. Disk is granted to an active process until it's budget (number of sectors) expires. BFQ assigns high budgets to non-read tasks. Budget assigned to a process varies over time as a function of it's behavior.
Advantages:
• Believed to be very good for usb data transfer rate.
• Believed to be the best scheduler for HD video recording and video streaming. (because of less jitter as compared to CFQ and others)
• Considered an accurate i/o scheduler.
• Achieves about 30% more throughput than CFQ on most workloads.
Disadvantages:
• Not the best scheduler for benchmarking.
• Higher budget assigned to a process can affect interactivity and increased latency.
5) SIO
Simple I/O scheduler aims to keep minimum overhead to achieve low latency to serve I/O requests. No priority quesues concepts, but only basic merging. Sio is a mix between noop & deadline. No reordering or sorting of requests.
Advantages:
• Simple, so reliable.
• Minimized starvation of requests.
Disadvantages:
• Slow random-read speeds on flash drives, compared to other schedulers.
• Sequential-read speeds on flash drives also not so good.
6) V(R)
Unlike other schedulers, synchronous and asynchronous requests are not treated separately, instead a deadline is imposed for fairness. The next request to be served is based on it's distance from last request.
Advantages:
• May be best for benchmarking because at the peak of it's 'form' VR performs best.
Disadvantages:
• Performance fluctuation results in below-average performance at times.
• Least reliable/most unstable.
Q. "Best I/O Scheduler?"
A.There is nothing called "best" i/o scheduler. Depending on your usage environment and tasks/apps been run, use different schedulers. That's the best i can suggest.
However, considering the overall performance, battery, reliability and low latency, it is believed that
SIO > Noop > Deadline > VR > BFQ > CFQ, given all schedulers are tweaked and the storage used is a flash device.
Xperia Ray->iPhone 4s->Nexus 5
Click to expand...
Click to collapse

Pilz said:
Here is some info I found by searching the forum posted by another member. I take no credit for this post because I did not write it:
Click to expand...
Click to collapse
Most of those are CPU Governors, not GPU Governors. Yeah theres "powersave" and "performance" but thats common knowledge.

zephiK said:
Most of those are CPU Governors, not GPU Governors. Yeah theres "powersave" and "performance" but thats common knowledge.
Click to expand...
Click to collapse
You're right, I read governor and immediately thought CPU

Pilz said:
You're right, I read governor and immediately thought CPU
Click to expand...
Click to collapse
its okay, we all have those days. But yeah to OP, use what is the default.
No need to change GPU Governors and not a good idea to use FauxClock for a kernel other than Faux Kernel.
Franco hid the option to change GPU Governor to simplify things for the user. I'm sure we've all been there where we used a kernel that has 10 pages of configurations from VRAM, Memory, CPU, GPU, Colors, Page Swap, etc. All of that confuses the user on what to set, and if they set it improperly they'll blame the kernel for not meeting their standards etc.
Just a simple underclock of GPU to 389-500 MHz would be better than setting a GPU Governor to "powersave." In my eyes, dont sacrifice performance for better battery but seek a compromise between performance and battery so that both sides will be happy. That way you'll maximize battery life while maintaining performance

Great answer thank you so much!
Sent from my Nexus 6

[DISCUSSION] [CPU governors] [I/O schdulers and more]

I have created this thread to discuss what cpu and gpu governors are best for battery life, why do you use such governor or scheduler and etc!
Feel free for posting your own opinion,battery results!
But dont forget to wrtie which KERNEL do you use.
Usefull information:
CPU governors:
1: OnDemand
2: OndemandX
3: Performance
4: Powersave
5: Conservative
6: Userspace
7: Min Max
8: Interactive
9: InteractiveX
10: Smartass
11: SmartassV2
12: Scary
13: Lagfree
14: Smoothass
15: Brazilianwax
16: SavagedZen
17: Lazy
18: Lionheart
19: LionheartX
20: Intellidemand
21: Hotplug
22: BadAss
23: Wheatley
24: Lulzactive
25: Pegasusq/Pegasusd
26: hotplugx
27: AbissPlug
28: MSM DCVS
29: IntelliActive
30: Adaptive
31: Nightmare
32: ZZmove
1: OnDemand Governor:
This governor has a hair trigger for boosting clockspeed to the maximum speed set by the user. If the CPU load placed by the user abates, the OnDemand governor will slowly step back down through the kernel's frequency steppings until it settles at the lowest possible frequency, or the user executes another task to demand a ramp.
OnDemand has excellent interface fluidity because of its high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand is commonly chosen by smartphone manufacturers because it is well-tested, reliable, and virtually guarantees the smoothest possible performance for the phone. This is so because users are vastly more likely to ***** about performance than they are the few hours of extra battery life another governor could have granted them.
This final fact is important to know before you read about the Interactive governor: OnDemand scales its clockspeed in a work queue context. In other words, once the task that triggered the clockspeed ramp is finished, OnDemand will attempt to move the clockspeed back to minimum. If the user executes another task that triggers OnDemand's ramp, the clockspeed will bounce from minimum to maximum. This can happen especially frequently if the user is multi-tasking. This, too, has negative implications for battery life.
2: OndemandX:
Basically an ondemand with suspend/wake profiles. This governor is supposed to be a battery friendly ondemand. When screen is off, max frequency is capped at 500 mhz. Even though ondemand is the default governor in many kernel and is considered safe/stable, the support for ondemand/ondemandX depends on CPU capability to do fast frequency switching which are very low latency frequency transitions. I have read somewhere that the performance of ondemand/ondemandx were significantly varying for different i/o schedulers. This is not true for most of the other governors. I personally feel ondemand/ondemandx goes best with SIO I/O scheduler.
3: Performance Governor:
This locks the phone's CPU at maximum frequency. While this may sound like an ugly idea, there is growing evidence to suggest that running a phone at its maximum frequency at all times will allow a faster race-to-idle. Race-to-idle is the process by which a phone completes a given task, such as syncing email, and returns the CPU to the extremely efficient low-power state. This still requires extensive testing, and a kernel that properly implements a given CPU's C-states (low power states).
4: Powersave Governor:
The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.
5:Conservative Governor:
This biases the phone to prefer the lowest possible clockspeed as often as possible. In other words, a larger and more persistent load must be placed on the CPU before the conservative governor will be prompted to raise the CPU clockspeed. Depending on how the developer has implemented this governor, and the minimum clockspeed chosen by the user, the conservative governor can introduce choppy performance. On the other hand, it can be good for battery life.
The Conservative Governor is also frequently described as a "slow OnDemand," if that helps to give you a more complete picture of its functionality.
6: Userspace Governor:
This governor, exceptionally rare for the world of mobile devices, allows any program executed by the user to set the CPU's operating frequency. This governor is more common amongst servers or desktop PCs where an application (like a power profile app) needs privileges to set the CPU clockspeed.
7: Min Max
well this governor makes use of only min & maximum frequency based on workload... no intermediate frequencies are used.
8: Interactive Governor:
Much like the OnDemand governor, the Interactive governor dynamically scales CPU clockspeed in response to the workload placed on the CPU by the user. This is where the similarities end. Interactive is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.
Unlike OnDemand, which you'll recall scales clockspeed in the context of a work queue, Interactive scales the clockspeed over the course of a timer set arbitrarily by the kernel developer. In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. This can eliminate the frequency bouncing discussed in the OnDemand section. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. This is another pro-battery life benefit of Interactive.
However, because Interactive is permitted to spend more time at maximum frequency than OnDemand (for device performance reasons), the battery-saving benefits discussed above are effectively negated. Long story short, Interactive offers better performance than OnDemand (some say the best performance of any governor) and negligibly different battery life.
Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above.
9: InteractiveX Governor:
Created by kernel developer "Imoseyon," the InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to better balance battery vs. performance. The InteractiveX governor's defining feature, however, is that it locks the CPU frequency to the user's lowest defined speed when the screen is off.
10: Smartass
Is 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 352Mhz (or if your min frequency is higher than 352 – why?! – it will cap it to your min frequency). Lets take for example the 528/176 kernel, it will sleep at 352/176. No need for sleep profiles any more!"
11: SmartassV2:
Version 2 of the original smartass governor from Erasmux. Another favorite for many a people. The governor aim for an "ideal frequency", and ramp up more aggressively towards this freq and less aggressive after. It uses different ideal frequencies for screen on and screen off, namely awake_ideal_freq and sleep_ideal_freq. This governor scales down CPU very fast (to hit sleep_ideal_freq soon) while screen is off and scales up rapidly to awake_ideal_freq (500 mhz for GS2 by default) when screen is on. There's no upper limit for frequency while screen is off (unlike Smartass). So the entire frequency range is available for the governor to use during screen-on and screen-off state. The motto of this governor is a balance between performance and battery.
12: Scary
A new governor wrote based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It will give the same performance as conservative right now, it will get tweaked over time.
13: Lagfree:
Lagfree is similar to ondemand. Main difference is it's optimization to become more battery friendly. Frequency is gracefully decreased and increased, unlike ondemand which jumps to 100% too often. Lagfree does not skip any frequency step while scaling up or down. Remember that if there's a requirement for sudden burst of power, lagfree can not satisfy that since it has to raise cpu through each higher frequency step from current. Some users report that video playback using lagfree stutters a little.
14: Smoothass:
The same as the Smartass “governor” But MUCH more aggressive & across the board this one has a better battery life that is about a third better than stock KERNEL
15: Brazilianwax:
Similar to smartassV2. More aggressive ramping, so more performance, less battery
16: SavagedZen:
Another smartassV2 based governor. Achieves good balance between performance & battery as compared to brazilianwax.
17: Lazy:
This governor from Ezekeel is basically an ondemand with an additional parameter min_time_state to specify the minimum time CPU stays on a frequency before scaling up/down. The Idea here is to eliminate any instabilities caused by fast frequency switching by ondemand. Lazy governor polls more often than ondemand, but changes frequency only after completing min_time_state on a step overriding sampling interval. Lazy also has a screenoff_maxfreq parameter which when enabled will cause the governor to always select the maximum frequency while the screen is off.
18: Lionheart:
Lionheart is a conservative-based governor which is based on samsung's update3 source.
The tunables (such as the thresholds and sampling rate) were changed so the governor behaves more like the performance one, at the cost of battery as the scaling is very aggressive.
19: LionheartX
LionheartX is based on Lionheart but has a few changes on the tunables and features a suspend profile based on Smartass governor.
20: Intellidemand:
Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. Unlike what some users believe, this governor is not the replacement for OC Daemon (Having different governors for sleep and awake). The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode. We can see some 'traces' of interactive governor here. Frequency scale-up decision is made based on idling time of CPU. Lower idling time (= 70%, cpu is scaled up 2 steps - to 800.
If current frequency =1200, Every down_sampling_time Us if cpu load < 70%, cpu is scaled down 1 step - to 1000.
25: Pegasusq/Pegasusd
The Pegasus-q / d is a multi-core based on the Ondemand governor and governor with integrated hot-plugging.
Ongoing processes in the queue, we know that multiple processes can run simultaneously on. These processes are active in an array, which is a field called "Run Queue" queue that is ongoing, with their priority values ​​arranged (priority will be used by the task scheduler, which then decides which process to run next).
To ensure that each process has its fair share of resources, each running for a certain period and will eventually stop and then again placed in the queue until it is your turn again. If a program is terminated, so that others can run the program with the highest priority in the current queue is executed.
26: hotplugx
It 'a Hotplug modified and optimized for the suspension in off-screen
27: AbissPlug
It 'a Governor derived hotplug, it works the same way, but with the changes in savings for a better battery.
28: MSM DCVS
a very efficient and wide range of Dynamic Clock and
Voltage Scaling (DCVS) which addresses usage models from
active standby to mid and high level processing requirements.
A Krait CPU can smoothly scale from low power, low
leakage mode to blazingly fast performance.
Believe it's a governor that is mfg'd by qualcomm to utilize new on chip features.
MSM is the prefix for the SOC (MSM8960) and DCVS is Dynamic Clock and Voltage Scaling. Makes sense, MSM-DCVS
29: IntelliActive
Based off Google's Interactive governor with the following enhancements:
1. self-boost capability from input drivers (no need for PowerHAL assist)
2. two phase scheduling (idle/busy phases to prevent from jumping directly to max freq
3. Checks for offline cpus and short circuits some unnecessary checks to improve code execution paths
30: Adaptive
This driver adds a dynamic cpufreq policy governor
designed for latency-sensitive workloads and also for demanding
performance.
This governor attempts to reduce the latency of clock
increases so that the system is more responsive to
interactive workloads in loweset steady-state but to
to reduce power consumption in middle operation level level up
will be done in step by step to prohibit system from going to
max operation level.
31: Nightmare
A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery.
In addition to the SoD is a prevention because it usually does not hotplug.
32: ZZmove
ZZmove Governor optimized for low power consumption with the screen off, with particular attention to the limitation of consumption applications in the background with the screen off, such as listening to music. It has three settings: battery saver, balanced and performance. In addition to a performance boost, there is also the governor zzmove optimized.
I/O schedulers:
1) Noop
Inserts all the incoming I/O requests to a First In First Out queue and implements request merging. Best used with storage devices that does not depend on mechanical movement to access data (yes, like our flash drives). Advantage here is that flash drives does not require reordering of multiple I/O requests unlike in normal hard drives.
Advantages:
Serves I/O requests with least number of cpu cycles. (Battery friendly?)
Best for flash drives since there is no seeking penalty.
Good throughput on db systems.
Disadvantages:
Reduction in number of cpu cycles used is proportional to drop in performance.
2) Deadline
Goal is to minimize I/O latency or starvation of a request. The same is achieved by round robin policy to be fair among multiple I/O requests. Five queues are aggressively used to reorder incoming requests.
Advantages:
Nearly a real time scheduler.
Excels in reducing latency of any given single I/O.
Best scheduler for database access and queries.
Bandwidth requirement of a process - what percentage of CPU it needs, is easily calculated.
Like noop, a good scheduler for solid state/flash drives.
Disadvantages:
When system is overloaded, set of processes that may miss deadline is largely unpredictable.
3) CFQ
Completely Fair Queuing scheduler maintains a scalable per-process I/O queue and attempts to distribute the available I/O bandwidth equally among all I/O requests. Each per-process queue contains synchronous requests from processes. Time slice allocated for each queue depends on the priority of the 'parent' process. V2 of CFQ has some fixes which solves process' i/o starvation and some small backward seeks in the hope of improving responsiveness.
Advantages:
Considered to deliver a balanced i/o performance.
Easiest to tune.
Excels on multiprocessor systems.
Best database system performance after deadline.
Disadvantages:
Some users report media scanning takes longest to complete using CFQ. This could be because of the property that since the bandwidth is equally distributed to all i/o operations during boot-up, media scanning is not given any special priority.
Jitter (worst-case-delay) exhibited can sometimes be high, because of the number of tasks competing for the disk.
4) BFQ
Instead of time slices allocation by CFQ, BFQ assigns budgets. Disk is granted to an active process until it's budget (number of sectors) expires. BFQ assigns high budgets to non-read tasks. Budget assigned to a process varies over time as a function of it's behavior.
Advantages:
Believed to be very good for usb data transfer rate.
Believed to be the best scheduler for HD video recording and video streaming. (because of less jitter as compared to CFQ and others)
Considered an accurate i/o scheduler.
Achieves about 30% more throughput than CFQ on most workloads.
Disadvantages:
Not the best scheduler for benchmarking.
Higher budget assigned to a process can affect interactivity and increased latency.
5) SIO
Simple I/O scheduler aims to keep minimum overhead to achieve low latency to serve I/O requests. No priority quesues concepts, but only basic merging. Sio is a mix between noop & deadline. No reordering or sorting of requests.
Advantages:
Simple, so reliable.
Minimized starvation of requests.
Disadvantages:
Slow random-read speeds on flash drives, compared to other schedulers.
Sequential-read speeds on flash drives also not so good.
6) V(R)
Unlike other schedulers, synchronous and asynchronous requests are not treated separately, instead a deadline is imposed for fairness. The next request to be served is based on it's distance from last request.
Advantages:
May be best for benchmarking because at the peak of it's 'form' VR performs best.
Disadvantages:
Performance fluctuation results in below-average performance at times.
Least reliable/most unstable.
7) Anticipatory
Based on two facts
i) Disk seeks are really slow.
ii) Write operations can happen whenever, but there is always some process waiting for read operation.
So anticipatory prioritize read operations over write. It anticipates synchronous read operations.
Advantages:
Read requests from processes are never starved.
As good as noop for read-performance on flash drives.
Disadvantages:
'Guess works' might not be always reliable.
Reduced write-performance on high performance disks.
Credits go to Google and XDA forum for provided information!

If you found new cpu and gpu governors or i/o schedulers with explanation just pm me(provide the link to post/site/thread)

reserved

Good thread
i am on hellscore kernel ver.b8.0
my setting
min cpu 652 max 1497 Hellsactive cpu governor , max cpu online at on time =3
UV=-35000uv
i/o=1024 KB AND fiops (when i set noop it's change )
i can't reach SOT More than 3h
what should i change

7sen said:
Good thread
i am on hellscore kernel ver.b8.0
my setting
min cpu 652 max 1497 Hellsactive cpu governor , max cpu online at on time =3
UV=-35000uv
i/o=1024 KB AND fiops (when i set noop it's change )
i can't reach SOT More than 3h
what should i change
Click to expand...
Click to collapse
Have you tried hellscore kernel app?(it supports n5)
Sent from my Nexus 5 using XDA Free mobile app

I'm using Hellscore 8.5-L with hellsactive governor. It's nice and smooth, with a medium battery life (can be improved with a few tweaks). Best I/O scheduler is FIOPS IMO.
otavio

What are the adventages of fiops compared to deadline ? I saw some comparisons showing that fiops has few higher scores in read / write tests, but what about battery management ? :/

I use UBER-L kernel with optipop rom and settings below :
- CPU max core = 2
- CPU freq min = 652 MHz
- CPU freq max = 1728 MHz
- CPU Governor = uberdemand
- Multicore power saving = aggressive
- CPU undervolt = -30 mV
- I/O scheduler = FIOPS
- I/O read-ahead = 2048 KB
- GPU governor = ondemand
- GPU max freq = 320 MHz
- GPU down threshold = 50
- GPU up treshold = 75
I can use my phone for 2 days with internet navigation, sms, calls and game each days.
GPS and wifi are disabled when i don't need it.

airbat said:
I use UBER-L kernel with optipop rom and settings below :
- CPU max core = 2
- CPU freq min = 652 MHz
- CPU freq max = 1728 MHz
- CPU Governor = uberdemand
- Multicore power saving = aggressive
- CPU undervolt = -30 mV
- I/O scheduler = FIOPS
- I/O read-ahead = 2048 KB
- GPU governor = ondemand
- GPU max freq = 320 MHz
- GPU down threshold = 50
- GPU up treshold = 75
I can use my phone for 2 days with internet navigation, sms, calls and game each days.
GPS and wifi are disabled when i don't need it.
Click to expand...
Click to collapse
How much time of SoT?
Sent from my Nexus 5 using XDA Free mobile app

Synapse tell me this :
Total = 100 %
sleep = 78,3 %
awake = 21,7 %
Most significant CPU states are :
300 MHz = 30%
652 MHz = 20 %
960 MHz = 5 %
1190 MHz = 5 %
1728 MHz = 38,8 %
I can't monitor GPU states actually son i can't tell which states are the most used.

Ah memories, i remember these from my XMP days, was a bit of a shock when i came on to N5 to find only 3-4 governors but then again i learned how to modify the existing governs for my liking. Most kernels ship with their own custom governors like elementalX. As for scheduling i switch between BFQ and noop.

I use ElementalX kernel.
Recommended governor.
However, by using BFQ as i/o scheduler and a larger read ahead value, this is the only way I've been able to avoid the audio/video playback buffer jitter that seems to be a lollipop introduced issue.
It isn't a perfect fix but seems to help a lot with smooth audio/video playback. Any latency that I can report is not so much a disadvantage. I can type fast and accurately still, and the frustration with not being able to listen to music without constant interruption was worse than any lag in responsiveness i have introduced. Gaming would probably suffer, but I don't game at all.

kgs1992 said:
Hey,
To the best of my understanding, they are I/O schedulers based on certain algorithms.
It's easy to explain if you know how queues are implemented.
noop is just a First In First Out standard queue of I/O operations.
cfq (Completely Fair Scheduling) is similar to the Round Robin algorithm and basically allots a fixed execution time for each I/O operation (they are implemented as a circular queue)
deadline is like a priority queue with an aging concept. Basically it adds a dealine for each I/O operation & implements a priority queue
Furthermore, there are 2 queues, one for read & one for write operations.
I'm sorry if this doesn't make sense, you just asked a technical question & I don't know how to explain better than this!
EDIT: Okay, I didn't see the link, most of the info I gave is present there.
EDIT: Here's an analogy, if people were queuing up to buy ice cream:
noop would implement the first come first serve rule.
cfq would let each person to buy one ice cream at a time & go back to the end of the queue if he wants another.
deadline would keep a separate queue for certain people (like older people & people who have been waiting for too long; somewhat setting a priority) & would serve the separate queue first.
Tried my best.
Click to expand...
Click to collapse
Here is an interesting explanation about schedulers. Credit to him.

FIOPS is hands on the best scheduler for the N5.
http://www.phoronix.com/scan.php?page=news_item&px=MTAzOTU
This new I/O scheduler is designed around the following assumptions about Flash-based storage devices: no I/O seek time, read and write I/O cost is usually different from rotating media, time to make a request depends upon the request size, and high through-put and higher IOPS with low-latency. With these flash characteristics in mind, he wrote FIOPS.
Click to expand...
Click to collapse
Pair FIOPS with f2fs, and you've got a winner.

JayR_L said:
FIOPS is hands on the best scheduler for the N5.
http://www.phoronix.com/scan.php?page=news_item&px=MTAzOTU
Pair FIOPS with f2fs, and you've got a winner.
Click to expand...
Click to collapse
agreed, have that setup right now
this thing flies

By the way, OP, I don't want to troll your thread, but just stating "XDA" in your sources. This doesn't credit the author.
So I'll do it for you.
http://forum.xda-developers.com/showthread.php?t=2222345
And he in turn just copied and pasted from various parts of the net, as he says in post number 8.
So please people, do some of your own research before believing everything you see on the net.

JayR_L said:
By the way, OP, I don't want to troll your thread, but just stating "XDA" in your sources. This doesn't credit the author.
So I'll do it for you.
http://forum.xda-developers.com/showthread.php?t=2222345
And he in turn just copied and pasted from various parts of the net, as he says in post number 8.
So please people, do some of your own research before believing everything you see on the net.
Click to expand...
Click to collapse
Oops
My fault
Sorry
Sent from my Nexus 5 using XDA Free mobile app

Dr.Pepper said:
If you found new cpu and gpu governors or i/o schedulers with explanation just pm me(provide the link to post/site/thread)
Click to expand...
Click to collapse
Oh yeah, I've found a lot of them here... :good:

Good thread. Wish pple would concentrate on the real life use of the phone and forget about benchmark. Noop, on demand, and Westwood. are the best trio when used together. Used them for years, with tests of others, but this works for me. Using Marchmellow and EX Kernel

[KERNEL][TW/LP][13.10.15][SM-T700][SM-T705] IronKernel V2.5 STweaks

Hey guys, I'm back with a new KERNEL for both Variants of the Tab S 8.4 (T700 and T705)!
Some guys probably know me from the IronRom . I decided myselfe to create a custom kernel for our really great Tab s 8.4, I'm getting better and better at this stuff, I don't thought that
It is basically the normal kernel with some modifications for better performance and hopefully also batterylife. It is for the stock kitkat (4.4.2) touchwiz and not for cyanogenmod or something else.
I excuse all devs here visiting my github page, it is such a mess (with the commits)! I know it, but I'm doing this the first time, so hopefully you will forgive me.
The kernel is pretty stable, I just call it a beta version, because I can't test the T700 and T705 version, so if with thisone also all works great -> stable
IF YOU FOLLOW MY STEPS BELOW, YOU WILL MAY LOSE YOUR WARRANTY, KNOX WILL DISPLAY 0x1! I'M NOT RESPONSIBLE FOR ANY DAMAGED DEVICE!
You can try to use the kernel adiutor app, or just the preinstalled sTweaks, but not both at the same time! This will cause problems.
Features of my Kernel::​- Built with latest Linaro Toolchain 4.9.3 made by christopher83
- Latest Kernel version 3.4.109, includes all important linux patches, patched it form 3.4.39 up to 3.4.109 (was a lot of work)
- Choose between different CPU governors: Interactive (default), Powersave, Performance, Userspace, Conservative, Intellidemand, Intelliactive, Ondemand, Adaptive, Abyssplug, AbyssplugV2, Badass, DanceDance, ZZmove, Nightmare, Wheatley, Lionheart, Darkness, PegasusQ and Intellimm
- Built with latest ramdisk sources from samsung
- Kernelsource from T805XXU1BOG2
- Underclock to 200MHz and Overclock to 2.0GHz
- GPU works from 100MHz to 733MHz (default)
- I/O schedulers: ROW (Default), CFQ, No-op, Deadline, Test, BFQ, FIOPS, SIO, VR, ZEN, FIFO and SIOplus
- Readahead can be set
- KSM (Kernel Samepage Merging)
- Gentlefairsleeper and ARCH power
- Android Logger
- Init.d Support
- data and cache f2fs support!
- Busybox support
- Full STweaks support
- Charging Control
- Cpufreq voltcontrol
- ZRam and Swap
- Allow ADB-Insecure
- Low Memory Kill
- TCP (Network) control: Cubic (default), Reno, Bic, Westwood, Highspeed, Hybla, HTCP, Vegas, Veno, Scalable, LP, Yeah and Illinois
- SeLinux is set to permissive
- Compiled as small as it could be (just around 6MB)
Download:​In the second post
Googy-Max STweaks​
Bugs/Problems:​-sTweaks can't enable the right GPU over and underclock freqency
-Some other stweaks stuff, you will see
-Didn't tried the voltage table​
Instructions:​
If you want to install the Kernel, follow this:
1. Install a custom recovery for your tablet, like this one here: TWRP Recovery
2. Follow the instructions on the page above, until you get a working recovery
3. Download the Kernel from below and copy it to your external SD Card
4. Reboot to your recovery by pressing volume up, home button and power button at the same time.
5. Install zip, and select the kernel
6. Wipe cache and dalvik cache (recommand)
7. Reboot
Support:​If you like my work, please hit a thanks down on my posts. A thanks is enough!:highfive: If you really really really really really like my work, you can donate something to me, but it is not necessary. I created a paypal account, just in case, someone would give me a small donation. :good:
As I said, you don't have to give me something, but this keeps me motivated to built better roms and keep updating everything. It's your choice, and I'm very thankfull for every donation! No matter how big it is! Thank you so much for supporting me, cheers and have a nice day :fingers-crossed:​
Donators for the Kernel:​
Credits/Thanks:​- Samsung for sources
- @Christopher83 for the compiler
- @UpInTheAir for the work he already did in his own kernel (could use some of his commits on github (opensource) and see what he did when I didn't know what I did wrong). He also inspired me to work on my own stuff and kernel, thank you very much!
- @googy_anas, without him, I would not have a working kernel here, he did so much for me and also for his own kernel! He
let me use everything he already did, I got so much stuff from his page and included it in my kernel. I'm so thankfull for all the support he gave to me! I know a thank you isn't enough, but I wanted to write it here.
- @googy_anas (again ) and @kryten2k35 for the great stweaks app and that I can use your modification in the app (I don't edited it) Thank you so much!
- @faux123 for all the great stuff he did for the kernels
- @Yank555
- @AndreiLux
- @Halaszk87
If you want to take my work and need it somewhere, or do other things with it, please ask me first for the permission. Otherwise you are not allowed to take it! Thank you !
XDA:DevDB Information
Stock Based Kernel for Tab S 8.4, Kernel for the Samsung Galaxy Tab S
Contributors
Tkkg1994, @googy_anas
Source Code: https://github.com/Tkkg1994/IronKernel
Kernel Special Features:
Version Information
Status: Stable
Current Stable Version: V2.5
Stable Release Date: 2015-10-13
Current Beta Version: 1.0
Beta Release Date: 2015-02-20
Created 2015-02-20
Last Updated 2015-10-12

Changelog:
Kitkat
Ironkernel Beta V1.0 20.02.2015:
- Initial Release!
Ironkernel V1.1 26.02.2015:
-Temporarly removed Intelli-Plug
-Added voltcontroll for CPU
-Added Stweaks support and Stweaks app (all credits and stuff goes to @googy_anas and @Kryten2k35
-Hell lot of improvements
-Init.d support and busybox support
-GPU overclock to 733MHz
-CPU overclock to 2.1GHz (sorry, I couldn't get it stable )
-Fast charge control
-for more what I had done, visit here: Commits IronKernel
IronKernel V1.2 01.03.2015:
- Built with latest toolchain (2015.02) by christopher83
- Use frandom from now
- Enable dynamic page writeback with earlysuspend
- Better battery charging control (kernel and stweaks)
- Auto install the right sTweaks version
- Reduce overestimating rq->avg_idle
- Optimize find_busiest_queue()
- Some CPUfreq optimizations
- Dynamic sync control with earlysuspend support
- Lowmemorykiller: implement task's adj rbtree
- Check free memory when tasks switch to background
- Dynamic FSync
- SOO Much more but I don't remember all
- After flashing the kernel, it will be successfull, but then show an error (becaus of mounting partition) don't worry, just reboot. Just ignore it
Changelog V1.3.5 08.03.15:
- Prerelease of V1.3 was on the ironrom
- Script auto-removes all knox containors/apps
- cpufreq: Retain only online cpus in managed_policy->cpus
- cpufreq: make the "scaling_cur_freq" sysfs entry pollable
- cpufreq: Make the "scaling_governor" sysfs node pollable
- cpufreq: Save and restore min and max frequencies
- fix some missing stuff with default governor
- cpufreq: Notify governors when cpus are hot-[un]plugged
- Updated nightmare and zzmoove governors
- net: ipv6: Add a sysctl to make optimistic addresses useful candidates
- fs/proc/task_mmu.c: add user-space support for resetting mm
- net: ipv6: allow choosing optimistic addresses with use_optimistic
- sched/idle: Avoid spurious wakeup IPIs
- cpufreq: Return directly in __cpufreq_get if policy is NULL
- new relation between governors
- ARM: 8226/1: cacheflush: get rid of restarting block
Changelog V1.4 23.03.15:
- It is simply to much to write everything here.. what I did
- Wolfson Control for the sound on our Tab S
- Added voltage control (doesen't work 100%)
- sched: Add an rq migration call-back to sched_class
- sched: Account for blocked load waking back up …
- sched: Normalize tg load contributions against runnable time
- sched: Refactor update_shares_cpu() -> update_blocked_avgs()
- sched/fair: Set se->vruntime directly in place_entity()
- sched: provide per cpu-cgroup option to notify on migrations
- sched: Make sure to not re-read variables after validation
- sched: Add WAKEUP_PREEMPTION feature flag, on by default
And this goes on for like 2 or 3 pages lol So the changelog is tooooooo long.
Lollipop
Changelog V2.0 08.07.15:
- @Richcar confirmed that it works (trust him )
- updated to linux 3.4.108 mainstream
- f2fs update
- add tripndroid scheduler
- add row scheduler
- add and enable UKSM (ultra kernel samepage merging)
- update ramdisk to latest versions
- more things I may forgot
- ONLY for touchwiz lollipop! You MUST have a EO3 base or higher (your rom)
Changelog V2.0.5 16.07.15:
- Fixed "slow" charging (Thanks to AndreiLux and UpInTheAir!)
- Incrased sound so it will be a louder by default
- Some other small ramdisk fixes
- Update to OF1 and OF2 ramdisk
- You have to be on latest samsung based roms (as OEx or OFx) otherwise not booting!
Changelog V2.5 13.10.15:
- Merged latest OG2 source, adapted by OE9 source from T705, fully rebased kernel!
- Update to 5.2 toolchain compiled by myself!
- this kernel is now up-to-date with T800/T805 kernel!
- updated to 3.4.109 linux
- ftrace: Make all inline tags also include notrace
- compiler-gcc4.h: correct verion check for __compiletime_error
- compiler.h: add __visible
- compiler{,-gcc4}.h, bug.h: Remove duplicate macros
- some more optimisations concerning compiler
- msm: cpufreq: Only apply driver limits for scaling_min/max_freq writes
- drivers: cpufreq: Send a uevent when governor changes
- cpufreq: Save user policy min/max instead of policy min/max during hotplug
- cpufreq: Fix broken uevents for cpufreq governor and cpu devices
- cpufreq: Always allow update of user policy
- drivers: cpufreq: Upstream optimizations
- cpufreq: Export user_policy min/max
- cpufreq: Add policy notifiers
- cpufreq: Simplify cpufreq_add_dev()
- some more cpufreq things that I made
- cpufreq_stats: do not remove sysfs files if frequency table is not present
- sched/numa: Rewrite the CONFIG_NUMA sched domain support
- sched/numa: Fix the new NUMA topology bits
- sched/numa: Don't scale the imbalance
- sched/debug: Fix printing large integers on 32-bit platforms
- sched: Remove stale power aware scheduling remnants and dysfunctional knobs
- f2fs: update to latest version
- uksm: disabled by default
- fixed some Random reboots people had
- added pegasusq cpugovernor
- arm/crypto: Add optimized AES and SHA1 routines
- added cifs, nfs, exportfs, cdrom, all ramdisk support (joystick too)
- ARM: 7626/1: arm/crypto: Make asm SHA-1 and AES code Thumb-2 compatible
- ARM: 7723/1: crypto: sha1-armv4-large.S: fix SP handling
- ARM: 8119/1: crypto: sha1: add ARM NEON implementation
- ARM: 8120/1: crypto: sha512: add ARM NEON implementation
- a lot of other crypto optimisations (like 10 patches)
- cpufreq: Move get_cpu_idle_time() to cpufreq.c
- workqueue: set delayed_work->timer function on initialization
- workqueue: don't use WQ_HIGHPRI for unbound workqueues
- workqueue: factor out worker_pool from global_cwq
- workqueue: use @pool instead of @gcwq or @Cpu where applicable
- workqueue: separate out worker_pool flags
- workqueue: introduce NR_WORKER_POOLS and for_each_worker_pool()
- workqueue: reimplement WQ_HIGHPRI using a separate worker_pool
- hashtable: introduce a small and naive hashtable
- workqueue: use new hashtable implementation
- workqueue: drop @bind from create_worker()
- much more workqueue updates, to see them all, please visit here: Github Kernel Updates

Governors and I/O Scheduler:
Original Thread: Governor Explained, all credits go to @stempox
1: OnDemand
2: OndemandX
3: Performance
4: Powersave
5: Conservative
6: Userspace
7: Min Max
8: Interactive
9: InteractiveX
10: Smartass
11: SmartassV2
12: Scary
13: Lagfree
14: Smoothass
15: Brazilianwax
16: SavagedZen
17: Lazy
18: Lionheart
19: LionheartX
20: Intellidemand
21: Hotplug
22: BadAss
23: Wheatley
24: Lulzactive
25: Pegasusq/Pegasusd
26: hotplugx
27: AbissPlug
28: MSM DCVS
29: IntelliActive
30: Adaptive
31: Nightmare
32: ZZmove
1: OnDemand Governor:
This governor has a hair trigger for boosting clockspeed to the maximum speed set by the user. If the CPU load placed by the user abates, the OnDemand governor will slowly step back down through the kernel's frequency steppings until it settles at the lowest possible frequency, or the user executes another task to demand a ramp.
OnDemand has excellent interface fluidity because of its high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand is commonly chosen by smartphone manufacturers because it is well-tested, reliable, and virtually guarantees the smoothest possible performance for the phone. This is so because users are vastly more likely to ***** about performance than they are the few hours of extra battery life another governor could have granted them.
This final fact is important to know before you read about the Interactive governor: OnDemand scales its clockspeed in a work queue context. In other words, once the task that triggered the clockspeed ramp is finished, OnDemand will attempt to move the clockspeed back to minimum. If the user executes another task that triggers OnDemand's ramp, the clockspeed will bounce from minimum to maximum. This can happen especially frequently if the user is multi-tasking. This, too, has negative implications for battery life.
2: OndemandX:
Basically an ondemand with suspend/wake profiles. This governor is supposed to be a battery friendly ondemand. When screen is off, max frequency is capped at 500 mhz. Even though ondemand is the default governor in many kernel and is considered safe/stable, the support for ondemand/ondemandX depends on CPU capability to do fast frequency switching which are very low latency frequency transitions. I have read somewhere that the performance of ondemand/ondemandx were significantly varying for different i/o schedulers. This is not true for most of the other governors. I personally feel ondemand/ondemandx goes best with SIO I/O scheduler.
3: Performance Governor:
This locks the phone's CPU at maximum frequency. While this may sound like an ugly idea, there is growing evidence to suggest that running a phone at its maximum frequency at all times will allow a faster race-to-idle. Race-to-idle is the process by which a phone completes a given task, such as syncing email, and returns the CPU to the extremely efficient low-power state. This still requires extensive testing, and a kernel that properly implements a given CPU's C-states (low power states).
4: Powersave Governor:
The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.
5:Conservative Governor:
This biases the phone to prefer the lowest possible clockspeed as often as possible. In other words, a larger and more persistent load must be placed on the CPU before the conservative governor will be prompted to raise the CPU clockspeed. Depending on how the developer has implemented this governor, and the minimum clockspeed chosen by the user, the conservative governor can introduce choppy performance. On the other hand, it can be good for battery life.
The Conservative Governor is also frequently described as a "slow OnDemand," if that helps to give you a more complete picture of its functionality.
6: Userspace Governor:
This governor, exceptionally rare for the world of mobile devices, allows any program executed by the user to set the CPU's operating frequency. This governor is more common amongst servers or desktop PCs where an application (like a power profile app) needs privileges to set the CPU clockspeed.
7: Min Max
well this governor makes use of only min & maximum frequency based on workload... no intermediate frequencies are used.
8: Interactive Governor:
Much like the OnDemand governor, the Interactive governor dynamically scales CPU clockspeed in response to the workload placed on the CPU by the user. This is where the similarities end. Interactive is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.
Unlike OnDemand, which you'll recall scales clockspeed in the context of a work queue, Interactive scales the clockspeed over the course of a timer set arbitrarily by the kernel developer. In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. This can eliminate the frequency bouncing discussed in the OnDemand section. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. This is another pro-battery life benefit of Interactive.
However, because Interactive is permitted to spend more time at maximum frequency than OnDemand (for device performance reasons), the battery-saving benefits discussed above are effectively negated. Long story short, Interactive offers better performance than OnDemand (some say the best performance of any governor) and negligibly different battery life.
Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above.
9: InteractiveX Governor:
Created by kernel developer "Imoseyon," the InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to better balance battery vs. performance. The InteractiveX governor's defining feature, however, is that it locks the CPU frequency to the user's lowest defined speed when the screen is off.
10: Smartass
Is 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 352Mhz (or if your min frequency is higher than 352 – why?! – it will cap it to your min frequency). Lets take for example the 528/176 kernel, it will sleep at 352/176. No need for sleep profiles any more!"
11: SmartassV2:
Version 2 of the original smartass governor from Erasmux. Another favorite for many a people. The governor aim for an "ideal frequency", and ramp up more aggressively towards this freq and less aggressive after. It uses different ideal frequencies for screen on and screen off, namely awake_ideal_freq and sleep_ideal_freq. This governor scales down CPU very fast (to hit sleep_ideal_freq soon) while screen is off and scales up rapidly to awake_ideal_freq (500 mhz for GS2 by default) when screen is on. There's no upper limit for frequency while screen is off (unlike Smartass). So the entire frequency range is available for the governor to use during screen-on and screen-off state. The motto of this governor is a balance between performance and battery.
12: Scary
A new governor wrote based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It will give the same performance as conservative right now, it will get tweaked over time.
13: Lagfree:
Lagfree is similar to ondemand. Main difference is it's optimization to become more battery friendly. Frequency is gracefully decreased and increased, unlike ondemand which jumps to 100% too often. Lagfree does not skip any frequency step while scaling up or down. Remember that if there's a requirement for sudden burst of power, lagfree can not satisfy that since it has to raise cpu through each higher frequency step from current. Some users report that video playback using lagfree stutters a little.
14: Smoothass:
The same as the Smartass “governor” But MUCH more aggressive & across the board this one has a better battery life that is about a third better than stock KERNEL
15: Brazilianwax:
Similar to smartassV2. More aggressive ramping, so more performance, less battery
16: SavagedZen:
Another smartassV2 based governor. Achieves good balance between performance & battery as compared to brazilianwax.
17: Lazy:
This governor from Ezekeel is basically an ondemand with an additional parameter min_time_state to specify the minimum time CPU stays on a frequency before scaling up/down. The Idea here is to eliminate any instabilities caused by fast frequency switching by ondemand. Lazy governor polls more often than ondemand, but changes frequency only after completing min_time_state on a step overriding sampling interval. Lazy also has a screenoff_maxfreq parameter which when enabled will cause the governor to always select the maximum frequency while the screen is off.
18: Lionheart:
Lionheart is a conservative-based governor which is based on samsung's update3 source.
The tunables (such as the thresholds and sampling rate) were changed so the governor behaves more like the performance one, at the cost of battery as the scaling is very aggressive.
19: LionheartX
LionheartX is based on Lionheart but has a few changes on the tunables and features a suspend profile based on Smartass governor.
20: Intellidemand:
Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. Unlike what some users believe, this governor is not the replacement for OC Daemon (Having different governors for sleep and awake). The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode. We can see some 'traces' of interactive governor here. Frequency scale-up decision is made based on idling time of CPU. Lower idling time (<20%) causes CPU to scale-up from current frequency. Frequency scale-down happens at steps=5% of max frequency. (This parameter is tunable only in conservative, among the popular governors)
To sum up, this is an intelligent ondemand that enters browsing mode to limit max frequency when GPU is idling, and (exits browsing mode) behaves like ondemand when GPU is busy; to deliver performance for gaming and such. Intellidemand does not jump to highest frequency when screen is off.
21: Hotplug Governor:
The Hotplug governor performs very similarly to the OnDemand governor, with the added benefit of being more precise about how it steps down through the kernel's frequency table as the governor measures the user's CPU load. However, the Hotplug governor's defining feature is its ability to turn unused CPU cores off during periods of low CPU utilization. This is known as "hotplugging."
22: BadAss Governor:
Badass removes all of this "fast peaking" to the max frequency. On a typical system the cpu won't go above 918Mhz and therefore stay cool and will use less power. To trigger a frequency increase, the system must run a bit @ 918Mhz with high load, then the frequency is bumped to 1188Mhz. If that is still not enough the governor gives you full throttle. (this transition should not take longer than 1-2 seconds, depending on the load your system is experiencing)
Badass will also take the gpu load into consideration. If the gpu is moderately busy it will bypass the above check and clock the cpu with 1188Mhz. If the gpu is crushed under load, badass will lift the restrictions to the cpu.
23: Wheatley:
Building on the classic 'ondemand' governor is implemented Wheatley governor. The governor has two additional parameters:
target_residency - The minimum average residency in µs which is considered acceptable for a proper efficient usage of the C4 state. Default is 10000 = 10ms.
allowed_misses - The number sampling intervals in a row the average residency is allowed to be lower than target_residency before the governor reduces the frequency. This ensures that the governor is not too aggressive in scaling down the frequency and reduces it just because some background process was temporarily causing a larger number of wakeups. The default is 5.
Wheatley works as planned and does not hinder the proper C4 usage for task where the C4 can be used properly .
For internet browsing the time spend in C4 has increased by 10% points and the average residency has increased by about 1ms. I guess these differences are mostly due to the different browsing behaviour (I spend the last time more multi-tabbing). But at least we can say that Wheatley does not interfere with the proper use of the C4 state during 'light' tasks. For music playback with screen off the time spend in C4 is practically unchanged, however the average residency is reduced from around 30ms to around 18ms, but this is still more than acceptable.
So the results show that Wheatley works as intended and ensures that the C4 state is used whenever the task allows a proper efficient usage of the C4 state. For more demanding tasks which cause a large number of wakeups and prevent the efficient usage of the C4 state, the governor resorts to the next best power saving mechanism and scales down the frequency. So with the new highly-flexible Wheatley governor one can have the best of both worlds.
Obviously, this governor is only available on multi-core devices.
24: Lulzactive:
Lulzactive:
This new find from Tegrak is based on Interactive & Smartass governors and is one of the favorites.
Old Version: When workload is greater than or equal to 60%, the governor scales up CPU to next higher step. When workload is less than 60%, governor scales down CPU to next lower step. When screen is off, frequency is locked to global scaling minimum frequency.
New Version: Three more user configurable parameters: inc_cpu_load, pump_up_step, pump_down_step. Unlike older version, this one gives more control for the user. We can set the threshold at which governor decides to scale up/down. We can also set number of frequency steps to be skipped while polling up and down.
When workload greater than or equal to inc_cpu_load, governor scales CPU pump_up_step steps up. When workload is less than inc_cpu_load, governor scales CPU down pump_down_step steps down.
Example:
Consider
inc_cpu_load=70
pump_up_step=2
pump_down_step=1
If current frequency=200, Every up_sampling_time Us if cpu load >= 70%, cpu is scaled up 2 steps - to 800.
If current frequency =1200, Every down_sampling_time Us if cpu load < 70%, cpu is scaled down 1 step - to 1000.
25: Pegasusq/Pegasusd
The Pegasus-q / d is a multi-core based on the Ondemand governor and governor with integrated hot-plugging.
Ongoing processes in the queue, we know that multiple processes can run simultaneously on. These processes are active in an array, which is a field called "Run Queue" queue that is ongoing, with their priority values ​​arranged (priority will be used by the task scheduler, which then decides which process to run next).
To ensure that each process has its fair share of resources, each running for a certain period and will eventually stop and then again placed in the queue until it is your turn again. If a program is terminated, so that others can run the program with the highest priority in the current queue is executed.
26: hotplugx
It 'a Hotplug modified and optimized for the suspension in off-screen
27: AbissPlug
It 'a Governor derived hotplug, it works the same way, but with the changes in savings for a better battery.
28: MSM DCVS
a very efficient and wide range of Dynamic Clock and
Voltage Scaling (DCVS) which addresses usage models from
active standby to mid and high level processing requirements.
A Krait CPU can smoothly scale from low power, low
leakage mode to blazingly fast performance.
Believe it's a governor that is mfg'd by qualcomm to utilize new on chip features.
MSM is the prefix for the SOC (MSM8960) and DCVS is Dynamic Clock and Voltage Scaling. Makes sense, MSM-DCVS
29: IntelliActive
Based off Google's Interactive governor with the following enhancements:
1. self-boost capability from input drivers (no need for PowerHAL assist)
2. two phase scheduling (idle/busy phases to prevent from jumping directly to max freq
3. Checks for offline cpus and short circuits some unnecessary checks to improve code execution paths
30: Adaptive
This driver adds a dynamic cpufreq policy governor
designed for latency-sensitive workloads and also for demanding
performance.
This governor attempts to reduce the latency of clock
increases so that the system is more responsive to
interactive workloads in loweset steady-state but to
to reduce power consumption in middle operation level level up
will be done in step by step to prohibit system from going to
max operation level.
31: Nightmare
A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery.
In addition to the SoD is a prevention because it usually does not hotplug.
32: ZZmove
ZZmove Governor optimized for low power consumption with the screen off, with particular attention to the limitation of consumption applications in the background with the screen off, such as listening to music. It has three settings: battery saver, balanced and performance. In addition to a performance boost, there is also the governor zzmove optimized.
I/O Scheduler: Thread:I/O Scheduler explained
The Scheduler is an algorithm that, given a set of requests for access to a resource, establishing a temporal order for the execution of such requests, favoring those that meet certain criteria in order to optimize access to that resource.
The difference between the various scheduler is the focus on certain criteria rather than on others.
The choice of a given scheduler does not produce visible changes so as to the choice of the governor, but still provides some improvements.
As usual schedulers are personally tested to find one that best suits your needs.
Deadline
It aims to provide a deadline, a deadline for all requests in order to avoid undesirable phenomena such as the "starvation" or the eternal waiting for some requests that occurs when one or more background processes are left indefinitely in the queue the ready, because there is always at least one of the highest priority ready process.
V (r)
The next request is performed according to the distance from the last request. In the network running good opinions about this scheduler.
No-op
Push all requests in a single queue simply by their arrival order, grouping together those contiguous.
SIO
E 'the scheduler simpler, does not make any type of sort, is intended only for the purpose of obtaining a low-latency, ie to reduce the amount of time that elapses between the instant at which the request is generated and that in which the request is satisfied.
CFQ
Order requests of different processes in queues for each queue type and assigns a specific interval of time whose duration depends on the priorities assigned to processes. Can be considered the Ondemand the scheduler, the scheduler is in fact more balanced, doing its job in an honest manner.
BFQ
It 's based on CFQ but, instead of the intervals of time, assigns a part of the bandwidth of the disc to each process running in a proportional manner.
Anticipatory
Order requests based on criteria predictive, that puts the demands paused for a short period of time in anticipation that more of this to come to aggregate them.
ADAPTIVE ANTICIPATORY SCHEDULER
For the anticipatory scheduler, we scale up the anticipation timeout (antic expire) using the latency scaling factor over time. When the virtual disk latencies are low a small scaling of the timeout is sucient to prevent deceptive idleness, whereas when the latencies are high a larger scaling of the timeout value may be required to achieve the same. Note that such dynamic setting of the timeout value ensures that we attain a good trade-o between throughput (lost due to idling) and deceptive idleness mitigation. Setting a high value for the scaling factor (increasing idling time) only happens when the disk service latencies themselves are higher. This may not necessarily cause a signicant loss in throughput, because submitting a request from another process instead of idling is not going to improve throughput if the virtual disk itself does not get any faster than it is at the current period. A higher anticipation timeout might also be capable of absorbing process scheduling eects inside the VM. The results for the adaptive anticipatory scheduler are shown in Figure 2. The read time with our modied implementation (third bar in the dierent scheduler combinations) shows that it is possible to mitigate the eects of deceptive idleness by adapting the timeout. An interesting related observation is that the level to which the improve- ment is possible varies for dierent Domain-0 schedulers; noop - 39%, anticipatory - 67% and cfq - 36%. This again points to the fact that the I/O scheduler used in Domain-0 is important for the VM's ability in enforcing I/O scheduling guarantees. Dierent Domain-0 I/O schedulers likely have a dierent service latency footprint inside the VMs, contributing to dierent levels of improvement.
ROW
Row stands for READ Over WRITE which is the main requests dispatch policy of this algorithm. The ROW IO scheduler was developed with the mobile devices needs in mind. In mobile devices we favor user experience upon everything else, thus we want to give READ IO requests as much priority as possible. In mobile devices we won't have as much parallel threads as on desktops. Usually it's a single thread or at most 2 simultaneous working threads for read & write. Favoring READ requests over WRITEs decreases the READ latency greatly.
The main idea of the ROW scheduling policy is: If there are READ requests in pipe - dispatch them but don't starve the WRITE requests too much. Bellow you'll find a small comparison of ROW to existing schedulers. The test that was run for these measurements is parallel read and write.
FIOS
Flash-based solid-state drives (SSDs) have the potential to eliminate the I/O bottlenecks in data-intensive applications However the large performance discrepancy between Flash reads and writes introduces challenges for fair resource usage. Further, existing fair queuing and quanta-based I/O schedulers poorly manage the I/O anticipation for Flash I/O fairness and efficiency. Some also suppress the I/O parallelism which causes substantial performance degradation on Flash. This paper develops FIOS, a new Flash I/O scheduler that attains fairness and high efficiency at the same time. FIOS employs a fair I/O time-slice management with mechanisms for read preference, parallelism, and fairness-oriented I/O anticipation. Evaluation demonstrates that FIOS achieves substantially better fairness and efficiency compared to the Linux CFQ scheduler, the SFQ(D) fair queuing scheduler, and the Argon quanta-based scheduler on several Flash-based storage devices (including a CompactFlash card in a low-power wimpy node). In particular, FIOS reduces the worst-case slowdown bya factor of 2.3 or more when the read-only SPECweb workload runs together with the write-intensive TPC

Can't wait to try this out on my t700

You might want to amend your OP. If you study the source code a little more and try understand things. You'll find there are no (actual) A7 100 MHz. A7 cores freq are doubled 100-650 (become 200-1300) MHz. A15 cores 800-1900+. Samsung have done it this way for IKS to work easily.
Some CPU control apps will just read the table but not able to differentiate between the A7 and A15 cores, and just display what's read from the frequency table.
You've made a good start, but 99% over those governors aren't suitable and/or optimized for Exynos. A "shotgun" approach isn't always the best way, but hey, this is your toy.

UpInTheAir said:
You might want to amend your OP. If you study the source code a little more and try understand things. You'll find there are no (actual) A7 100 MHz. A7 cores freq are doubled 100-650 (become 200-1300) MHz. A15 cores 800-1900+. Samsung have done it this way for IKS to work easily.
Some CPU control apps will just read the table but not able to differentiate between the A7 and A15 cores, and just display what's read from the frequency table.
You've made a good start, but 99% over those governors aren't suitable and/or optimized for Exynos. A "shotgun" approach isn't always the best way, but hey, this is your toy.
Click to expand...
Click to collapse
Now I understand that a little bit more. Because I added first a 100MHz support and added all stuff to get it work and than, it displayed me 50MHz and I thought, what the heck is going wrong here?
So I removed it again. Thank you for helping out here.
Suitable are they, but optimized not at the moment. You know, otherwise I wont have work left
And that's also why I call it a beta version at the moment.

Tkkg1994 said:
Now I understand that a little bit more. Because I added first a 100MHz support and added all stuff to get it work and than, it displayed me 50MHz and I thought, what the heck is going wrong here?
So I removed it again. Thank you for helping out here.
Suitable are they, but optimized not at the moment. You know, otherwise I wont have work left
And that's also why I call it a beta version at the moment.
Click to expand...
Click to collapse
No, a lot are not suitable, as they are written for krait SoC (4 main cores), just like intelli-plug etc. I found they were more of a hassle and eroded kernel stability, hence I never committed the changes for release. You might find otherwise, so no harm to try. Can be fun, and also a headache too
Snapdragon 810 will be using big.LITTLE architecture same as Exynos, so hopefully faux will port some of his work over. Although it will be HMP, maybe we can adapt to our IKS kernel.

UpInTheAir said:
No, a lot are not suitable, as they are written for krait SoC (4 main cores), just like intelli-plug etc. I found they were more of a hassle and eroded kernel stability, hence I never committed the changes for release. You might find otherwise, so no harm to try. Can be fun, and also a headache too
Snapdragon 810 will be using big.LITTLE architecture same as Exynos, so hopefully faux will port some of his work over. Although it will be HMP, maybe we can adapt to our IKS kernel.
Click to expand...
Click to collapse
Nobody says that we can't port it to 8 cores you know, it is a lot of work for sure, but not impossible.
I barely had problems with the governors, more with intelliplug.
But I think it is good that we don't have the same opinion.
Otherwise we would have 2 similar kernels here.

Tkkg1994 said:
Nobody says that we can't port it to 8 cores you know, it is a lot of work for sure, but not impossible.
I barely had problems with the governors, more with intelliplug.
But I think it is good that we don't have the same opinion.
Otherwise we would have 2 similar kernels here.
Click to expand...
Click to collapse
I don't think you understand me yet. We use IKS and 4 cores at once big.LITTLE . NOT HMP (all cores running). If you study the governors and what exactly the frequency/cores are actually doing in real time, you will find out and learn from it ... Just because something compiles and are able to switch between variables, does not make it compatible.
I never said or implied that anything was impossible, but you need to re-write (not adapt) a lot of code. In effect, create a "new" governor. This is fact, not my opinion
Best of luck with your project, keep at it !

UpInTheAir said:
I don't think you understand me yet. We use IKS and 4 cores at once big.LITTLE . NOT HMP (all cores running). If you study the governors and what exactly the frequency/cores are actually doing in real time, you will find out and learn from it ... Just because something compiles and are able to switch between variables, does not make it compatible.
I never said or implied that anything was impossible, but you need to re-write (not adapt) a lot of code. In effect, create a "new" governor. This is fact, not my opinion
Best of luck with your project, keep at it !
Click to expand...
Click to collapse
I read the wiki article
I think our Exynos5 5420 use HMP and can use all cores together if it uses it?
I was talking about the intelli-plug stuff not the governors. I hope samsung will release a S6 with exynos (only) and than we will get more support.
If you want to talk with me (and yes I like to) than PM?

Tkkg1994 said:
I read the wiki article
I think our Exynos5 5420 use HMP and can use all cores together if it uses it?
I was talking about the intelli-plug stuff not the governors. I hope samsung will release a S6 with exynos (only) and than we will get more support.
If you want to talk with me (and yes I like to) than PM?
Click to expand...
Click to collapse
Keep reading and learning Particularly what IKS is and does. Please don't take this the wrong way, this is relevant and you really need to learn how the basics of our 5420 kernel actually work.
There have been test HMP for Exynos 5420, BUT, no Android powered Exynos 5420 is ever capable of HMP. AndreiLux has explained why in various posts.
HMP kernels (such as I'm using with my Note Edge Skyhigh kernel) is completely different, but some things might be adapted with little work.
I just don't have the time to answer or clarify every single question (I don't pretend to always know), even by PM. It's just a matter of reading, learning, and trial by many errors.

UpInTheAir said:
Keep reading and learning Particularly what IKS is and does. Please don't take this the wrong way, this is relevant and you really need to learn how the basics of our 5420 kernel actually work.
There have been test HMP for Exynos 5420, BUT, no Android powered Exynos 5420 is ever capable of HMP. AndreiLux has explained why in various posts.
HMP kernels (such as I'm using with my Note Edge Skyhigh kernel) is completely different, but some things might be adapted with little work.
I just don't have the time to answer or clarify every single question (I don't pretend to always know), even by PM. It's just a matter of reading, learning, and trial by many errors.
Click to expand...
Click to collapse
I'm doing this the first time, so hopefully you and the others will understand that. I hope you can excuse me I have to learn many things I know that.
See you soon!

Changelog V1.1:
-Temporarly removed Intelli-Plug
-Added voltcontroll for CPU
-Added Stweaks support and Stweaks app (all credits and stuff goes to @googy_anas and @Kryten2k35
-Hell lot of improvements
-GPU overclock to 733MHz
-CPU overclock to 2.1GHz (sorry, I couldn't get it stable )
-for more what I had done, visit here: Commits IronKernel

Tkkg1994 said:
-Temporarly removed Intelli-Plug
-Added voltcontroll for CPU
-Added Stweaks support and Stweaks app (all credits and stuff goes to @googy_anas and @Kryten2k35
-Hell lot of improvements
-GPU overclock to 733MHz
-CPU overclock to 2.1GHz (sorry, I couldn't get it stable )
-for more what I had done, visit here: Commits IronKernel
Click to expand...
Click to collapse
Kernel update is awesome I love the GPU OC seems stable also went to 2GHZ CPU OC no issues I would go to 2.1GHZ but I think it may get unstable
TAPATALKED WITH MY XPE R IA Z
My Z3 app Ports to all devices

danny19901 said:
Kernel update is awesome I love the GPU OC seems stable also went to 2GHZ CPU OC no issues I would go to 2.1GHZ but I think it may get unstable
TAPATALKED WITH MY XPE R IA Z
My Z3 app Ports to all devices
Click to expand...
Click to collapse
Better let it at 2.0 GHz. Best for stability! Great you enjoy it

danny19901 said:
Kernel update is awesome I love the GPU OC seems stable also went to 2GHZ CPU OC no issues I would go to 2.1GHZ but I think it may get unstable
TAPATALKED WITH MY XPE R IA Z
My Z3 app Ports to all devices
Click to expand...
Click to collapse
N/A

fishdrop said:
N/A
Click to expand...
Click to collapse
Just putting N/A doesn't help much if you need help or something

New changelog:
IronKernel V1.2 01.03.2015:
- Built with latest toolchain (2015.02) by christopher83
- Use frandom from now
- Enable dynamic page writeback with earlysuspend
- Better battery charging control (kernel and stweaks)
- Auto install the right sTweaks version
- Reduce overestimating rq->avg_idle
- Optimize find_busiest_queue()
- Some CPUfreq optimizations
- Dynamic sync control with earlysuspend support
- Lowmemorykiller: implement task's adj rbtree
- Check free memory when tasks switch to background
- Dynamic FSync
- SOO Much more but I don't remember all
- After flashing the kernel, it will be successfull, but then show an error (becaus of mounting partition) don't worry, just reboot. Just ignore it

THANKYOU !!! Why is it that most other developers can't use common sense and say right up front that their work will kill Knox.

hillg001 said:
THANKYOU !!! Why is it that most other developers can't use common sense and say right up front that their work will kill Knox.
Click to expand...
Click to collapse
This won't actually trip Knox counter...
By installing a custom recovery (pre-requisite to install kernel.zip) will already trip the counter, and not within the scope of most Developers concern. Wouldn't the user already have tripped the counter prior to flashing the kernel? Think about it. .. Having the warning in OP doesn't hurt though

Team-M8 AOSP kernel MM & LP 3.4.110, GCC 5.3 Antutu 78k+, Battery 5 days+

Team-M8 AOSP kernel
What is it?
This project was initially based on Unicornblood kernel from DirtyUnicorns (@smac0628), which is current with linux 3.4.110. She and I are working together on this project to make a better experience for users.
We aim to include as many tweaks as possible to this AOSP kernel while maintaining stability. We also make extensive efforts to properly give credit the authors of the many features we've added (picked only the original author's commits, instead of kanging entire files).
Settings have intentionally been chosen which favor battery life over performance. With that said, you can definitely squeak out a little better battery life, or you can have some fun and get killer performance instead.
Features:
Hotplugs (only enable one!, more on the way):
IntelliPlug
Great balance between battery life and performance. It is also a popular hotplug driver from faux123.
MSM Hotplug
Great battery life, a custom qualcomm based hotplugging driver by myflux. It is a popular choice for many users.
Alucard Hotplug
A great hotplugging driver by Alucard. It is known to be very battery friendly on devices.
Zen Decision
ZEN only onlines all cores when screen is on, it also takes thermal events into account and wont online any core back, if you're under 15% battery, or currently have a thermal event because of heat. So in the end it isn't a "real" hotplug driver, because it doesnt have any code for active hot plugging in it. That means you can't change its behavior.
Hybrid Hotplug/Governor (Disable all hotplugs if you're going to use this)
zzmoove
The ZZmoove Governor by ZaneZam is optimized for low power consumption when the screen off, with particular attention to the limitation of consumption applications in the background with the screen off, such as listening to music. The unique feature with ZZmoove is that it has predefined profiles and allows profile switching. This governor is still a WIP as the developer is constantly giving updates! Here are the available profiles:
Quote:
1) for Default (set governor defaults)
2) for Yank Battery -> old untouched setting (a very good battery/performance balanced setting DEV-NOTE: highly recommended!)
3) for Yank Battery Extreme -> old untouched setting (like yank battery but focus on battery saving)
4) for ZaneZam Battery -> old untouched setting (a more 'harsh' setting strictly focused on battery saving DEV-NOTE: might give some lags!)
5) for ZaneZam Battery Plus -> NEW! reworked 'faster' battery setting (DEV-NOTE: recommended too! )
6) for ZaneZam Optimized -> old untouched setting (balanced setting with no focus in any direction DEV-NOTE: relict from back in the days, even though some people still like it!)
7) for ZaneZam Moderate -> NEW! setting based on 'zzopt' which has mainly (but not strictly only!) 2 cores online
8) for ZaneZam Performance -> old untouched setting (all you can get from zzmoove in terms of performance but still has the fast down scaling/hotplugging behaving)
9) for ZaneZam InZane -> NEW! based on performance with new auto fast scaling active. a new experience!
10) for ZaneZam Gaming -> NEW! based on performance with new scaling block enabled to avoid cpu overheating during gameplay
11) for ZaneZam Relax -> NEW! based on moderate (except hotplug settings) with relaxed sleep settings
(since version 0.9 beta4: cpu temperature threshold of 65°C enabled if exynos4 cpu temperature reading support was compiled with the governor)
Click to expand...
Click to collapse
CPU Governors (more on the way):
A CPU governor in Android controls how the CPU raises and lowers its frequency in response to the demands the user is placing on their device. Governors are especially important in smartphones and tablets because they have a large impact on the apparent fluidity of the interface and the battery life of the device over a charge.
Abyssplugv2
AbyssPlugv2 is a rewrite of the original CPU governor. It also fixes the problem where the governor is set only for the first core, but now governs all cores right from whatever utility you use. There have been comments on the lack of stability with this governor.
alucard
A favourite choice and one of the original governors that Alucard_24 made. Alucard is based on ondemand but has been heavily tweaked to bring better battery life and performance. It has been known to be battery friendly without sacrificing much performance.
badass
Badass removes all of this "fast peaking" to the max frequency. To trigger a frequency increase, the system must run a bit with high load, then the frequency is bumped. If that is still not enough the governor gives you full throttle. (this transition should not take longer than 1-2 seconds, depending on the load your system is experiencing)
Badass will also take the gpu load into consideration. If the gpu is moderately busy it will bypass the above check and clock the cpu to max frequency, If the gpu is crushed under load, badass will lift the restrictions to the cpu
dancedance
Based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It is a performance focused governor but also blends with some battery savings.
darkness
It's based on nightmare but more simple and fast, basic configs but very complex structure. It is an updated nightmare gov and improved stability, so far it is quite stable in tests
elementalx
If you are an owner of a nexus device, you probably have heard of a governor named ElementalX. Named after the kernel, elementalX is based on interactive but with some additional performance tweaks. This governor focuses on performance and not battery savings!
hellsactive
A heavily modified intelliactive governor by @hellsgod that has been tweaked to improve battery life. Hellsactive is less aggressive compared to intelliactive so the battery life will be more like the original interactive.
intelliactive
Based off Google's Interactive governor with the following enhancements:
1. self-boost capability from input drivers (no need for PowerHAL assist)
2. two phase scheduling (idle/busy phases to prevent from jumping directly to max freq
3. Checks for offline cpus and short circuits some unnecessary checks to improve code execution paths. Therefore, it avoids CPU hotplugging.
This is a more performance oriented CPU governor that still has great battery life like the original Interactive.
intellidemand
Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode.
To sum up, this is an intelligent ondemand that enters browsing mode to limit max frequency when GPU is idling, and (exits browsing mode) by behaving like ondemand when GPU is busy; to deliver performance for gaming and such. Intellidemand does not jump to highest frequency when screen is off.
intellimm
A rewrite of the old Min Max governor and has 3 cpu states: Idle, UI and Max. Intelliminmax (intellimm) governor is designed to work with the newer SOCs with fixed voltage rails (ie MSM8974+ SOCs). It is designed to work within those fixed voltage ranges in order to maximize battery performance while creating a smooth UI operations. It is battery friendly and spends most of the time at lower frequencies.
nightmare
A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery. In addition to the SoD is a prevention because it usually does not hotplug.
ondemand
Ondemand is one of the original and oldest governors available on the linux kernel. When the load placed on your CPU reaches the set threshold, the governor will quickly ramp up to the maximum CPU frequency. It has excellent fluidity because of this high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand was commonly chosen by smartphone manufacturers in the past because it is well-tested and reliable, but it is outdated now and is being replaced by Google's Interactive governor.
smartmax
Ondemand is one of the original and oldest governors available on the linux kernel. When the load placed on your CPU reaches the set threshold, the governor will quickly ramp up to the maximum CPU frequency. It has excellent fluidity because of this high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand was commonly chosen by smartphone manufacturers in the past because it is well-tested and reliable, but it is outdated now and is being replaced by Google's Interactive governor.
yankactive
A slightly modified interactive based governor by Yank555.lu. It has battery tweaks added onto it so expect better battery life! Based on user reports, this governor behaves more battery friendly than the original interactive governor without sacrificing performance.
yankdemand
Full stock (JB) ondemand governor with changed default tunable values aimed at lower battery consumption
interactive
Google's own take on a CPU governor. Interactive scales the clockspeed over the course of a timer set by the kernel developer (or user). In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. It is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.
Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above.
Interactive is the default governor of choice for today's smartphone and tablet manufacturers.
performance
The performance governor locks the phone's CPU at maximum frequency.
The descriptions in this post were created by @gsstudios and can be found here:
http://forum.xda-developers.com/general/general/ref-to-date-guide-cpu-governors-o-t3048957
Voltage Control (UV/OV)
OC to 2880 MHz
UC to 268 MHz
Set Max frequency in Screen-Off state
As the name says, you get to set a different governer when screen is off. This will override what you chose in the governer choice. Pretty nifty arrangement so that you can flip from a performance governer when on screen and a power save governer when screen is off. This feature was added to the kernel because it was either the developers intention or by popular demand.
Force Fastcharge
A. When set, the phone will charge off of the PC USB ports as if it is connected to wall outlet. This does turn off your access to the phone internal memory and SD card. If you want to access the internal storage on PC then you have to turn this off.
NOTE – Weather to turn on or off, has to be done before connecting to PC. Changing this after connecting has no effect.
Kexec hardboot patch (can be flashed as primary bootimage in multirom)
GPU Governors:
cpubw_hwmon
A hardware (HW) monitor based governor that attempts to determine bandwidth needed by CPU and other hardware. This is a unique GPU governor that is highly customisable, however it is known to be unstable on some devices.
msm_cpufreq
The MSM CPUfreq governor determines the CPU to DDR bandwidth vote based on the current CPU frequency of all the active CPUs. In other words, this governor scales based on CPU usage which could mean more performance.
msm-adreno-tz
The default GPU governor used by qualcomm for their adreno GPUs. It is more performance orientated than ondemand therefore it gives better performance in games but less battery life.
userspace
This governor basically allows the user is able to set a desired frequency for the GPU to run at.
powersave
Like the CPU governor, this keeps your GPU running at the lowest possible frequency. Best battery life, extreme lag in games.
performance
As the name suggests, this keeps your GPU running at the max frequency. This is a governor if you want the best possible experience in games but you don't care about your battery life.
simple_ondemand
KCal display adjustments
IO Schedulers:
Input/output (I/O) scheduling is a term used to describe the method computer operating systems decide the order that block I/O operations will be submitted to storage volumes. I/O Scheduling is sometimes called 'disk scheduling'.
I/O schedulers can have many purposes depending on the goal of the I/O scheduler, some common goals are:
- To minimise time wasted by hard disk seeks.
- To prioritise a certain processes' I/O requests.
- To give a share of the disk bandwidth to each running process.
- To guarantee that certain requests will be issued before a particular deadline.
bfq
Instead of time slices allocation by CFQ, BFQ assigns budgets. Disk is granted to an active process until it's budget (number of sectors) expires. BFQ assigns high budgets to non-read tasks. Budget assigned to a process varies over time as a function of it's behavior.
Benefits:
- Has a very good USB data transfer rate.
- The best scheduler for playback of HD video recording and video streaming (due to less jitter than CFQ Scheduler, and others)
- Regarded as a very precise working Scheduler
- Delivers 30% more throughput than CFQ
- Being constantly updated
- Good for multitasking, more responsive than CFQ
Disadvantages:
- Not the best scheduler for benchmarks
- Higher budgets that were allocated to a process that can affect the interactivity and bring with it increased latency.
cfq
Completely Fair Queuing scheduler maintains a scalable per-process I/O queue and attempts to distribute the available I/O bandwidth equally among all I/O requests. Each per-process queue contains synchronous requests from processes. Time slice allocated for each queue depends on the priority of the 'parent' process. V2 of CFQ has some fixes which solves process' i/o starvation and some small backward seeks in the hope of improving responsiveness.
Benefits:
- Has a well balanced I / O performance
- Excellent on multiprocessor systems
- Regarded as a stable I/O scheduler
- Good for multitasking
Disadvantages:
- Some users report media scanning takes longest to complete using CFQ. This could be because of the property that since the bandwidth is equally distributed to all i/o operations during boot-up, media scanning is not given any special priority.
- Jitter (worst case delay) can sometimes be very high because the number of competing with each other process tasks
- Under constant load, the phone will experience increased I / O latency due to the way how the scheduler tries to create 'fairness'
deadline
The goal of the Deadline scheduler is to attempt to guarantee a start service time for a request. It does that by imposing a deadline on all I/O operations to prevent starvation of requests. It also maintains two deadline queues, in addition to the sorted queues (both read and write). Deadline queues are basically sorted by their deadline (the expiration time), while the sorted queues are sorted by the sector number.
Before serving the next request, the Deadline scheduler decides which queue to use. Read queues are given a higher priority, because processes usually block on read operations. Next, the Deadline scheduler checks if the first request in the deadline queue has expired. Otherwise, the scheduler serves a batch of requests from the sorted queue. In both cases, the scheduler also serves a batch of requests following the chosen request in the sorted queue.
Benefits:
- Nearly a real-time scheduler.
- Excels in reducing latency of any given single I/O
- Best scheduler for database access and queries.
- Does quite well in benchmarks, most likely the best
- Like noop, a good scheduler for solid state/flash drives
Disadvantages:
- If the phone is overloaded, crashing or unexpected closure of processes can occur
fifo
First in First Out Scheduler. As the name says, it implements a simple priority method based on processing the requests as they come in.
Benefits:
- Serves I/O requests with least number of cpu cycles.
- Is suitable for flash drives because there is no search errors
- Good data throughput on db systems
Disadvantages:
- Reducing the number of CPU cycles corresponds to a simultaneous decline in performance
- Not very good at multitasking
fiops
This new I/O scheduler is designed around the following assumptions about Flash-based storage devices: no I/O seek time, read and write I/O cost is usually different from rotating media, time to make a request depends upon the request size, and high through-put and higher IOPS with low-latency. FIOPS (Fair IOPS) ioscheduler tries to fix the gaps in CFQ. It's IOPS based, so it only targets for drive without I/O seek. It's quite similar like CFQ, but the dispatch decision is made according to IOPS instead of slice.
Benefits:
- Achieves high read and write speeds in benchmarks
- Faster app launching time and overall UI experience
- Good battery life
Disadvantages:
- Not very common in most kernels
- Not the most responsive IO scheduler (Can make phone lag)
- Not good at heavy multitasking
noop
Inserts all the incoming I/O requests to a First In First Out queue and implements request merging. Best used with storage devices that does not depend on mechanical movement to access data (yes, like our flash drives). Advantage here is that flash drives does not require reordering of multiple I/O requests unlike in normal hard drives.
Benefits:
- Serves I/O requests with least number of cpu cycles.
- Is suitable for flash drives because there is no search errors
- Good data throughput on db systems
- Good battery life
- Does great in benchmarks
- Also a very reliable IO scheduler
Disadvantages:
- Reducing the number of CPU cycles corresponds to a simultaneous decline in performance
- Not the most responsive I/O scheduler
- Not very good at multitasking (especially heavy workloads)
row
The ROW IO scheduler was developed with the mobile devices needs in mind. In mobile devices, we favor user experience upon everything else, thus we want to give READ IO requests as much priority as possible. In mobile devices we won't have as much parallel threads as on desktops. Usually it's a single thread or at most 2 simultaneous working threads for read & write. Favoring READ requests over WRITEs decreases the READ latency greatly. The main idea of the ROW scheduling policy is: If there are READ requests in pipe - dispatch them but don't starve the WRITE requests too much.
Benefits:
- Faster UI navigation and better overall phone experience
- Faster boot times and app launch times
Disadvantages:
- Not great for heavy multitasking
- Slower write speeds
sio
Simple I/O scheduler aims to keep minimum overhead to achieve low latency to serve I/O requests. No priority quesues concepts, but only basic merging. Sio is a mix between noop & deadline. No reordering or sorting of requests.
Benefits:
- It is simple and stable.
- Minimized starvation for inquiries
- Good battery life
Disadvantages:
- Slow random write speeds on flash drives as opposed to other schedulers.
- Sequential read speeds on flash drives are not as good as other IO schedulers
tripndroid
A new I/O scheduler based on noop, deadline and vr and meant to have minimal overhead. Made by TripNRaVeR
Benefits:
- Great at IO performance and everyday multitasking
- Well rounded and efficient IO scheduler
- Very responsive I/O scheduler (Compared to FIOPS)
Disadvantages:
- Not found in all kernels
- Performance varies between different devices (Some devices perform really well)
vr
Unlike other scheduling software, synchronous and asynchronous requests are not handled separately, but it will impose a fair and balanced within this deadline requests, that the next request to be served is a function of distance from the last request.
Benefits:
- Generally excels in random writes.
Disadvantages:
- Performance variability can lead to different results (Only performs well sometimes)
- Sometimes unstable and unreliable
zen
ZEN scheduler is based on the VR Scheduler. It's an FCFS (First come, first serve) based algorithm, but it's not strictly FIFO. ZEN does not do any sorting. It uses deadlines for fairness, and treats synchronous requests with priority over asynchronous ones. Other than that, it's pretty much the same as no-op blended with VR features.
Benefits:
- Well rounded IO Scheduler
- Very efficient IO Scheduler
- More stable than VR, more polished
Disadvantages:
- Performance variability can lead to different results (Only performs well sometimes)
- Not found in all kernels
LED Control
Z-Ram
Q. What is ZRAM?
A. ZRAM basically compresses unused apps within the system RAM. This allows the system to swap less needed processes to the zram partition for faster access at a later time, instead of killing them. This does take up some of your ram though, so I imagine that the value you are setting is determining exactly what percentage of your ram that the zram partition is allotted.
FSYNC
TCP Congestion Algorithms:
Congestion control strategies (or algorithms) are used by TCP, the data transmission protocol used by many Internet applications. The main goal of a TCP algorithm is to avoid sending more data than the network is capable of transmitting, that is, to avoid causing network congestion. Different algorithms respond differently to network loads, but they are all based on the same principle of avoiding network congestion.
Things to look out for in TCP algorithms include (but not exclusively):
- Download/Upload speeds - The higher the number, the better
- Latency - The lower the number, the better
bic
Binary Increase Congestion control (BIC):
BIC is optimized for high speed networks with high latency: so-called "long fat networks". It has a unique congestion window (cwnd) algorithm. This algorithm tries to find the maximum where to keep the window at for a long period of time, by using a binary search algorithm.
lp
Low Priority (LP):
A distributed algorithm whose goal is to utilize only the excess network bandwidth as compared to the "fair share" of bandwidth as targeted by TCP. The key mechanisms unique to TCP-LP congestion control are the use of one-way packet delays for early congestion indications and a TCP-transparent congestion avoidance policy.
highspeed
High speed (HSTCP):
High Speed TCP (HSTCP) is a new congestion control algorithm protocol for TCP. Standard TCP performs poorly in networks with a large bandwidth delay product. It is unable to fully utilize available bandwidth. HSTCP makes minor modifications to standard TCP's congestion control mechanism to overcome this limitation.
htcp
Hamilton TCP (HTCP):
HTCP is designed for high-speed, long distance networks that increases aggressiveness as the time since the previous loss increases. It is thought to be a more efficient TCP algorithm than BIC and HSTCP.
hybla
Hybla:
Penalizes connections that use satellite radio. Not usually used with phones.
illinois
Illinois is designed for high-speed, long-distance networks. A sender side modification to the standard TCP congestion control algorithm, it achieves a higher average throughput than the standard TCP and allocates the network resource fairly as the standard TCP.
scalable
Scalable calls for congestion window to be halved for each packet lost. Effectively, this process keeps halving the throughput until packet loss stops. Once the packet loss subsides, slow start kicks in to ramp the speed back up.
vegas
One of the smoothest TCP algorithms(next to cubic), it increases the timeout delay for packets, which allows more to be received, but at a higher rate. It also has set timeouts, which helps with speed because it's constantly being refreshed.
veno
Veno is closely related to Vegas, it is a combination of Vegas and Reno in order to enhance TCP performance over Wireless networks.
westwood
A newer version of Reno, and another commonly used one. It controls parameters better, helping out streaming and overall quality of browsing the internet. One of the most 'fair' algorithms out there, and is one of the most efficient algorithms to date.
yeah
A high speed TCP congestion control algorithm which uses a mixed loss/delay approach to calculate congestion windows. Its purpose is to target high efficiency, fairness, and minimizing link loss while keeping network elements load as low as possible.
reno
Basically the same as Tahoe, but if 3 of the same packets are received, it will halve the window, instead of reducing it to one. It changes the slow start threshold equal to that of the congestion window.
cubic
One of the best, most recommended TCP options available. Less aggressive, Inflects the windows prior to the event. Used in Linux.
Sweep to Wake, Sweep to Sleep, Double-tap to Wake (for these features, please build from branch master-s2w)
How do you get it?
That's a hard question to answer, surprisingly. You're free to flash the zip file below, but it's only the zImage. While this zip will include nearly everything you'll want or need, what you need for OC/UC is part actually of the dts. The dts is another piece that gets packed together with the zImage to make the boot.img. Unfortunately there's all sorts of ramdisk & permissions issues which can be caused by flashing a boot.img, so it's not recommended.
Please make a nandroid before doing anything! Backing up the boot partition takes all of a second and 16 megs of storage. Just do it! Also, do not hold us responsible for anything that happens to your device. It's worked fantastically for us, but you're flashing at your own risk.
Downloads for MM
Download for LP (no Sweep to Wake)
Download for LP (with Sweep to Wake)
The very best method of getting the kernel, is to have it compiled with the ROM itself (as with all kernels).
O.P. is a WIP. Will be adding and editing a lot, especially at first.
Special thanks to @izzaeroth for assisting with the Anykernel zip.
XDA:DevDB Information
Team-M8 AOSP kernel, Kernel for the HTC One (M8)
Contributors
fizbanrapper, smac0628, amirfida
Source Code: https://github.com/Team-M8/android_kernel_htc_msm8974/tree/master
Kernel Special Features:
Version Information
Status: Beta
Created 2015-11-10
Last Updated 2016-08-16

Want to get the most out of your kernel?
What does that mean to you? Battery savings? Performance? Balance between them?
The "most" is a difficult question to even attempt to answer. Even assuming we could define "balance between them", I still could not give you a set of settings that would work well for everyone. Not only are you all using different variants, but you're using different builds of different ROMs with different gapps packages, different apps, different usage habits, and in different areas of the country.
You really have to get an understanding of what different things do, then decide for yourself how you should customize your settings. Trial and error!
How did I get those scores on antutu? Here's a response I provided to that very question later in the thread:
fizbanrapper said:
I don't recall the exact settings, but I'll give you general guidelines.
When I test any kernel, I think it's critical to level the playing field as much as possible. I run it on my primary ROM with PAC ROM. I run few apps on it and disable anything that might sync in the background.
Disable all hotplugs and thermal drivers. Make sure your phone has been booted for a good 5 minutes so that your thermal temps have had a chance to come back down. Since you've disabled your thermal drivers, there's a decent chance you'll get a force reboot half way through the test if you're starting off with a high cpu temp already.
Used one of the zzmoove governor profiles. I think I used zram and disabled fsync too.
If my memory serves me right, this got me to back to back scores of 52776 and 52713.
Click to expand...
Click to collapse

Want great battery life?
Set your governor's max frequency to 268000 (yankactive is pretty good for this).
Set max frequency policy to 268000. Do the same for screen off max as well as any applicable input boost settings.
Set multicore powersaving mode to aggressive.
Choose one hotplug and choose the most conservative settings available.
Don't worry, your device won't completely listen to your request to only run at 268000 under all circumstances. Unfortunately every kernel I've ever run for this device (Team-M8, CM, Candy, DU, Slim, Blissful, Furnace, PAC, and B14ckb1rd) all disrespect my wishes! Abyssplug governor is the only notable exception here.
I'll try to provide more detailed settings when I get more time.

First

Not first! ?....oh wait...
SECOND!?
Great work getting this all together with so many sweet options!

Congrats on releasing this new kernel. I've updated the governor/scheduler guide to include missing description on Yankdemand for people who were curious
gsstudios

gsstudios said:
Congrats on releasing this new kernel. I've updated the governor/scheduler guide to include missing description on Yankdemand for people who were curious
gsstudios
Click to expand...
Click to collapse
Thanks! That was fast! I've updated the OP with your description.

I flashed this on the latest AICP (Android Ice Cold Project) and it kills my data. I'm also on Verizon if that matters...

GohanBurner said:
I flashed this on the latest AICP (Android Ice Cold Project) and it kills my data. I'm also on Verizon if that matters...
Click to expand...
Click to collapse
I've never heard of that happening g from a kernel. Could it be something else causing this? Anyone else experiencing this?

It has to be, I flash the kernel from CandyRom over it and data works again. Flash this again data doesn't work...

GohanBurner said:
It has to be, I flash the kernel from CandyRom over it and data works again. Flash this again data doesn't work...
Click to expand...
Click to collapse
It should work ok if compiled with the ROM. It's one of the downsides of the flashable zip.

Can a boot.img version of this be created? Or would that be just as good as a zip?

GohanBurner said:
Can a boot.img version of this be created? Or would that be just as good as a zip?
Click to expand...
Click to collapse
Well the boot.img would contain even more aicp-specific stuff. So if it was compiled from aicp's source, it would be fine as a boot.img.
If I compiled a boot.img from a ROM I've synced, it would cause even more compatibility issues than the zip.

I don't mind switching ROMs to use this kernel, which one are you running? I assume this will work with CM, correct?

GohanBurner said:
I don't mind switching ROMs to use this kernel, which one are you running? I assume this will work with CM, correct?
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Click to collapse
At the moment I'm on bliss. That's what it was compiled from. That used candy kernel though too, mostly. Let me look for a good build for you to try.

Try this
https://www.androidfilehost.com/?fid=24052804347848888

Try it without the kernel zip first, to make sure it works without it. Then go back and flash to get the updates.

Scozzar said:
What Kernel manager would you guys recommend for this kernel? I use Trickster, but it doesn't have the ability to select all of the hotplug options. With Trickster, I can only seem to choose between mp-decision or intelliplug.
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I've been using kernel adiutor

Scozzar said:
Ah much better. I'm running all the Alucard hotplug and governor. Battery life isn't great, but I did just flash it twenty minutes ago.
Sent from my m8 using Tapatalk
Click to expand...
Click to collapse
Try zzmoove or a different hotplug. Alucard might not be the right choice for you.

@smac0628 is a current and equal contributor to this project. She's the one who put the work into Unicornblood. I'll update the OP shortly so that this is more clear.
Feel free to keep whining to @Mazda and the mods though. Though I don't think any of them care, it is entertaining.

[KERNEL][OREO-PIE][TREBLE] Schwifty Kernel [vR5] | AOSP | 12/12/18 |

The Schwifty Kernel (Yeahhh, Get Schwifty)
Hello guys welcome to the Schwifty Kernel! If you watch the show "Rick and Morty" you will understand why I named it this if you don't understand well either youtube it or just don't worry and enjoy the sh*t out the kernel anyways hehe. Alright lets get Schwifty, here's all the info about the kernel in a way that will help you decide how you want to set up your phone! The second post will contain changelogs and third post, well not sure yet. But enjoy!!​
Basic Specifications/Information:
Based On Axon 7 LoS 16.1 Kernel Source
Updated to the latest linux kernel source (3.18.126)
Built with Custom CrossTool-NG Toolchain (GCC: 8.2.0)
Allow 5-10 to settle in after booting up for better usage
Take the time to read all the information to get an understanding on the kernel (Will help with less bug reports)
If you report a bug please search before posting and give all information about your issue (Such as rom, kernel version, kernel setup... ect)
I will edit the page with dates when there is something new added such as govenors, schedulers ect...
I/O Scheduler Information - I/O:
NOOP - Inserts all the incoming I/O requests to a First In First Out queue and implements request merging. Best used with storage devices that does not depend on mechanical movement to access data (yes, like our flash drives). Advantage here is that flash drives does not require reordering of multiple I/O requests unlike in normal hard drives.
DEADLINE - The goal of the Deadline scheduler is to attempt to guarantee a start service time for a request. It does that by imposing a deadline on all I/O operations to prevent starvation of requests. It also maintains two deadline queues, in addition to the sorted queues (both read and write). Deadline queues are basically sorted by their deadline (the expiration time), while the sorted queues are sorted by the sector number. Before serving the next request, the Deadline scheduler decides which queue to use. Read queues are given a higher priority, because processes usually block on read operations. Next, the Deadline scheduler checks if the first request in the deadline queue has expired. Otherwise, the scheduler serves a batch of requests from the sorted queue. In both cases, the scheduler also serves a batch of requests following the chosen request in the sorted queue.
BFQ - Instead of time slices allocation by CFQ, BFQ assigns budgets. Disk is granted to an active process until it's budget (number of sectors) expires. BFQ assigns high budgets to non-read tasks. Budget assigned to a process varies over time as a function of it's behavior.
ZEN & ZEN v2 - Based on the Noop, Deadline and SIO I/O schedulers. It's an FCFS (First come, first serve) based algorithm, but it's not strictly FIFO. ZEN does not do any sorting. It uses deadlines for fairness, and treats synchronous requests with priority over asynchronous ones.
MAPLE(8/30) - is based on the Zen and Simple I/O schedulers. It uses ZEN's first-come-first-serve style algorithm with separate read/write requests and improved former/latter request handling from SIO. Maple is biased towards handling asynchronous requests before synchronous, and read requests before write. While this can have negative aspects on write intensive tasks like file copying, it slightly improves UI responsiveness. When the device is asleep, maple increases the expiry time of requests so that it can handle them more slowly, causing less overhead.
Governor Information - CPU:
Interactive - Interactive scales the clockspeed over the course of a timer set by the kernel developer (or user). In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. It is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency. Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above. Interactive is the default governor of choice for today's smartphone and tablet manufacturers.
Ondemand - Ondemand is one of the original and oldest governors available on the linux kernel. When the load placed on your CPU reaches the set threshold, the governor will quickly ramp up to the maximum CPU frequency. It has excellent fluidity because of this high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand was commonly chosen by smartphone manufacturers in the past because it is well-tested and reliable, but it is outdated now and is being replaced by Google's Interactive governor.
Performance - Sets the frequency at the maximum available frequency. This governor always returns UINT_MAX as frequency so that the DEVFREQ framework returns the highest frequency available at any time.
Powersave - Sets the frequency at the minimum available frequency. This governor always returns 0 as frequency so that the DEVFREQ framework returns the lowest frequency available at any time.
Userspace - Sets the frequency at the user specified one. This governor returns the user configured frequency if there has been an input to /sys/devices/.../power/devfreq_set_freq. Otherwise, the governor does not change the frequnecy given at the initialization.
GPU Governors:
Adreno Idler - It is an idling algorithm, an efficient workaround for msm-adreno-tz's overheads. Main goal is to lower the power consumptions while maintaining high-performance. Since msm-adreno-tz tends to *not* use the lowest frequency even on idle, Adreno idler replaces msm-adreno-tz's algorithm when it comes to calculating idle frequency(mostly by ondemand's method). The higher frequencies are not touched with this algorithm, so high-demanding games will (most likely) not suffer from worsened performance.
Simple - An open-source alternative to Qualcomm's closed-sourced governors. Developed by Faux123, it is highly customisable which will allow more fine-grained control over how the GPU scales up and down.
simple_ondemand[/b] - As the name implies, it is a simpler version of the CPU governor ondemand. simple_ondemand will ramp up the frequency when a load is detected. It has a good balance between performance and battery savings.
msm-adreno-tz - The default GPU governor used by Qualcomm for their adreno GPUs. It is based on the ondemand governor but is biased towards performance, therefore it should give better performance in games but less battery life.
Performance - As the name suggests, this keeps your GPU running at the max frequency. This is a governor if you want the best possible experience in games but you don't care about your battery life.
Powersave - Like the CPU governor, this keeps your GPU running at the lowest possible frequency. Best battery life, extreme lag in games.
Userspace - This governor basically allows the user is able to set a desired frequency for the GPU to run at.
cpubw_hwmon - A hardware monitor based governor that attempts to determine bandwidth (BW) needed by CPU and other hardware. Because it samples bandwidth using polling intervals, it has been made to be biased towards performance to compensate for the possible slower response times during heavy loads.
MSM Cpufreq - The MSM CPUfreq governor determines the CPU to DDR bandwidth vote based on the current CPU frequency of all the active CPUs. In other words, this governor scales based on CPU usage which could mean more performance.
Other Information:
Moved Core Control To Kernel - Moved core control from out-of-tree module into the kernel proper. Core control monitors load on CPUs and controls how many CPUs are available for the system to use at any point in time. This can help save power. Core control can be configured through sysfs interface.
Moved Core Control Trace Events To Scheduler
Added A Knob To Disable The core_ctl (Core Control) - The CPU hotplug tests does not work with core_ctl compiled statically into kernel. Provide an interface to disable the hotplug by core_ctl.
Updated the performance is cpufreq
Lots of UPSTREAM changes to cpuidle and schedulers
Some under and overclocks with how the phone idles and returns
Added a State Notifyier
Added CAD Project
Imported Boeffla Wakelock Blocker v1.1.0
Updated Kcal Support
Fixed Various Issues
Low Persistence Fixed For DayDream
Selinux Switcher Between Permissive & Enforcing (Please install the Magisk SELinux Manager)
And a whole lot of other sh*t, view the github to see all the changes
Credit:
@OrdenKrieger
@Unjustified Dev
@Skrem339
Tester:
@kingracer
@KevinX8
@Masterjuggler
@Choose an username...
@docentore
@Infy_AsiX
Disclaimer: I do not and will not take any responsibility towards anything that happens to your phone after flashing.
If you would like to donate a beer or a blunt feel free, its not obligated though! Each donation is appreciate by being added to OP!
​
XDA:DevDB Information
[KERNEL][OREO][AOSP] Schwifty Kernel | Custom | 6/8/17 |, Kernel for the ZTE Axon 7
Contributors
SaintZ93
Source Code: https://github.com/SaintZ13/schwifty_oreo_axon7
Kernel Special Features:
Version Information
Status: Stable
Current Stable Version: v1
Stable Release Date: 2018-06-24
Created 2018-06-25
Last Updated 2018-06-24

Install Instructions:
Boot To Recovery
Flash Schwifty Kernel
Wipe Dalvik & Cache
Re-flash Magisk
Downloads:
Stable Release: vR5 Changelog (12/12/18)
Download:
https://www.androidfilehost.com/?fid=11410963190603873368
Click to expand...
Click to collapse
MD5: ef8222968aaea32fed85245d53599c56
Kernel Size: 13.6MB
Stable Release: vR4 (Treble & Non-Treble)
Changelog (8/30/18)
Download:
https://androidfilehost.com/?w=files&flid=281523
Click to expand...
Click to collapse
MD5: Treble - 55fb1a7e7dade9f560725f5bc135e4d7
Non-Treble - 69d034f21ba8b39330633c1b96bf8c97
Kernel Size: 13MB
Stable Release: vR3 (Treble & Non-Treble)
Changelog (7/30/18)
Download:
Treble said:
https://www.androidfilehost.com/?fid=5862345805528062503
Click to expand...
Click to collapse
Non-Treble said:
https://www.androidfilehost.com/?fid=5862345805528062511
Click to expand...
Click to collapse
MD5: Treble - f30ef3e8220146331f657195d46bc8b8
Non-Treble - dc055bcc684df594820e741c3e912be2
Kernel Size: 10.6MB
Stable Release: vR2
Changelog (7/3/18)
Download:
https://www.androidfilehost.com/?fid=11050483647474833482
Click to expand...
Click to collapse
MD5: 5f275eb139681e005f28986c6649560b
Kernel Size: 10.9MB
Schwifty Kernel: Initial Release (6/24/18):
Download:
https://www.androidfilehost.com/?fid=674106145207498193
Click to expand...
Click to collapse
MD5: c30d7ed7c4e7b2843f3ae83e9e75509b
ROM Size: 10.9MB

Reserved

Trying this right now, so far it seems to be stable. Battery life seems to be less right now but that may be due to other factors I'm still investigating.

Nice,new kernel.But why should i use this,and not Hellsgate?

Predatorhaze said:
Nice,new kernel.But why should i use this,and not Hellsgate?
Click to expand...
Click to collapse
Although fast, hellsgate kernel hasn't been kind to my device's stability personally speaking.
This could be more stable, since it doesn't seem to add hoards of features (and potential complications with them).

Predatorhaze said:
Nice,new kernel.But why should i use this,and not Hellsgate?
Click to expand...
Click to collapse
Try searching Schwifty kernel on Google, this kernel isn't new If I remember correctly there were great reviews for this kernel on the other device(LG V20). I don't mean that Hellsgate is not as good, I'm just saying this kernel has its own unique advantages(while Hellsgate is a mighty kernel with loads of features and great performance, so it's also no worse)

About DAC
DAC is working in this kernel?

Very nice kernel, it's stable, the battery holds very nicely and it's powerfull, the UI doesn't lag.
Thanks for your work!

is F2FS supported?

leska said:
is F2FS supported?
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Click to collapse
I tried, it seems so. F2FS and encryption working on my device (exfat also).

Good battery life. Fast and smooth. Stable.
Thank u!

Running this kernel for for about 12 hours now. Seems solid and I find my device to be snappier vs HellsGate. Battery life appears to be solid as well.

del

can someone report about battery life? and does this include COFB(Conservative Optimized For Battery), and it optimized for battery ? (Everything from CAD kernel)

Could you please build this for stock B12? Everything except wifi and hotspot works.

hmm on my device the kernel is a real battery killer.. can barely reach 2.5h screen on time where hellsgate gives me double
switching back now...

Guido83 said:
hmm on my device the kernel is a real battery killer.. can barely reach 2.5h screen on time where hellsgate gives me double
switching back now...
Click to expand...
Click to collapse
What kernel/ROM did you flash this over?

EBeatFLA said:
What kernel/ROM did you flash this over?
Click to expand...
Click to collapse
AEX latest build

New build will be coming within the next couple of days guys, stay tuned! Check the github for new changes.