Thursday, December 3, 2015

Ricky Febrian

All About Governors and HotPlugging and its effect from various kernel for Redmi 1s

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CPU Governors explained with there in performance,Battery life. Know which saves more battery and which governor give you Max performance.
All information about CPU and GPU Governor and Hot-plugging in taken from xda
Listed below are governors included in The Beast Kernel for Redmi 1s List will go up.
Lets Begin

CPU Governor's
1. OnDemand : is one of the original and oldest governors.
it will quickly ramp up to the maximum CPU frequency when the load placed on your CPU reaches the set threshold. It has excellent performance because of this high-frequency bias, but it 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OnDemand was commonly chosen by smartphone manufacturers in the past because it is well-tested and reliable, but it is outdated now and is being replaced by Google's Interactive governor
2. Performance : The performance governor locks the phone's CPU at maximum frequency. Not battery friendly.
3. Powersave : The opposite of the Performance governor, it locks the CPU frequency at the lowest frequency set by the user. Not Performance friendly LAG LAG LAG.
4. Conservative : Governor  prefer to set the lowest possible clock speed as often as possible.
The conservative governor can give best performance with good battery life.
5. Userspace : Its rare for mobile devices. Forget it.
6. 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 hot-plugging.
Created by Faux
7. Smartmax :  By default this is configured for Battery Saving so this is not for gamers
Input events from the touchscreen will boost the cpu for a specific time to a specific frequency. Developed by XDA user Maxwen
8. Yankactive : A slightly modified interactive based governor by
Include more battery tweaks - so expect better Battery Saving
9. Nightmare : A good Balance between performance and battery.
10. Impulse : Improved version of interactive governor. Aim to have a balance between battery and performance just like interactive but has some tweaks to save battery. modified by neobuddy89.
So if you are using interactive governor try this.
11. Darkness : Based on nightmare governor but more simple and fast.
12. Alucard : Alucard is based on ondemand governor but tweaked to bring better battery life and performance. It has been known to be battery friendly without sacrificing much performance.
Created by Alucard_24.
13. Interactive: Interactive is prepared to intermediate clockspeeds between the minimum and maximum CPU frequencies. It is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.

GPU Governor's
1. 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.
2. MSM-Adreno: 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. Still a balanced governor for everyday usage. 
3. Userspace: This governor basically allows the user is able to set a desired frequency for the GPU to run at. 
4. 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.
5. Powersave: Like the CPU governor, this keeps your GPU running at the lowest possible frequency. Best battery life, extreme lag in games.
6. Simple: It's a new governor for the gpu frequency scaling. It will allow a more fine grained control over how the gpu scales up and down then the previous ones. Depending how you tune it, it can be better for battery life or performance. 
7. Ondemand: Much like the CPU governor, Ondemand will ramp up the frequency when a load is detected. A good balance between performance and battery savings. This is a widely used governor in qualcomm devices.

CPU Hotplugging drivers:
1. mpdecision: Qualcomm's default hotplugging driver. One of the most widely used hotplug drivers in all android devices. 
2. msm_hotplug: Great battery life, a custom qualcomm based hotplugging driver by myflux. It is a popular choice for many users. 
3. intelliplug: Great balance between battery life and performance. It is also a popular hotplug driver from faux123. 
4. Alucard: A great hotplugging driver by Alucard. It is known to be very battery friendly on devices.
5. Adreno Idler: It is an idling algorithm, an efficient workaround for msm-adreno-tz overheads. Main goal is to lower the power consumption while maintaining high-performance.

I/O Scheduler:
1. CFQ: Well Balanced I/O Performance, Beneficial for multi-core processors and good for multitasking.
Media scanning is slow
2. Tripndroid : One of the best based on noop, deadline and vr, Best I/O performance and better multitasking.
3. FIOPS : Fair IOPS - Good for Battery life,faster app launching, increase in UI perfomance on the other hand sometimes can make phone lag, not for heavy multitasking.
4. ZEN: Based on vr scheduler but efficient and stable than vr. not a good performance scheduler.
For Size
Stability Use 128kB read-head value
Performance Use 2048kB read-head value
SD Card < 8GB Use 128kB read-head value
SD Card < 16GB Use 1024kB read-head value
SD Card 64GB+ Use 2048kB read-head value