Hi, just another cpu governor question:
Smartass VS Interactive, 122/710
Ive notice this behavior with these two via OS Monitor:
Interactive: This mod seems to adjust the cpu frequency based on current cpu usage, from 122 to 710 (and some steps between these two, again based on usage) - is my thinking correct?. Same should be for sleep, where is no cpu usage, therefore 122mhz or so.
Smartass - based on interactve, expected to be better: This one is also adjusting the cpu frequency when needed, but in ON mode its from 480 to 710 and when sleep its from 122 to 352.
When I know these two information (assuming they are correct) the interactive governor seems to be better for battery saving with same performance (idle system for few seconds - 480mhz vs 122mhz). Or is there any significant performance difference when interactive got such a huge scaling range? Did I miss something relevant when comparing these two?
Copy-Pasting a post from arco which explains Smartass:
"Smartass caps the frequency when screen on to 480 MHz to ensure responsiveness. This also helps with video playback being smooth, as it otherwise will begin to stutter when the frequency is lower than this."
The Interactive governor is designed to reach maximum speed with no lag, so there should not be any need to raise minimum speed just because the screen is on, but the smartass governor has been optimised for android so it must be a good choice.
Personally, I am testing the Conservative governor which should take about 2 seconds to get from min to max speed, and I am not seeing any difference from on-demand.
Standby battery life is improved by dropping min speed, you don`t NEED to change anything else.
I have been investigating this matter for 2 weeks now. Using SetCPU to set the governor and CPU Spy for monitoring, here's what I typically get on my Nexus S with Netarchy Kernel.
Ondemand
1000Mhz: 3%
800: 1%
400: 0%
200: 0%
100: 12%
Deep Sleep: 84%
Conservative
1000: 2%
800: 3%
400: 3%
200: 0%
100: 8%
Deep Sleep: 84%
Smartass
1000: 2%
800: 5%
600: 5%
400: 2%
200: 0%
100: 3%
Deep Sleep: 83%
Smartass looks more responsive but drains more battery. Surprisingly, ondemand should drain less battery than conservative.
What do you guys get?
Avoid the Conservative Governor - I am only using it for fun. It saves a small amount of power by picking up speed slowly, but wastes more by dropping speed even slower. I can improve that by messing with the source, but in standard form it is pretty hopeless.
SmartAss lets you drop speed in standby to ridiculously low levels without losing performance when the sceen is on. I couldn`t recommend anything else.
Ooops
There is a bug in the Conservative Governor : it is wasting power because it will not reduce CPU clock until CPU usage is below 10% (default).
Suggested fix:
--- /usr/src/ez/drivers/cpufreq/cpufreq_conservative.c 2011-04-25 01:51:20.000000000 +0100
+++ /usr/src/buzz35/drivers/cpufreq/cpufreq_conservative.c 2011-07-29 18:10:12.184895733 +0100
@@ -30,7 +30,7 @@
*/
#define DEF_FREQUENCY_UP_THRESHOLD (80)
-#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
+#define DEF_FREQUENCY_DOWN_THRESHOLD (70)
/*
* The polling frequency of this governor depends on the capability of
@@ -524,9 +524,9 @@
/*
* The optimal frequency is the frequency that is the lowest that
* can support the current CPU usage without triggering the up
- * policy. To be safe, we focus 10 points under the threshold.
+ * policy. To be safe, we should focus 10 points under the threshold.
*/
- if (max_load < (dbs_tuners_ins.down_threshold - 10)) {
+ if (max_load < dbs_tuners_ins.down_threshold) {
freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
this_dbs_info->requested_freq -= freq_target;
The conservative governor was designed to keep CPU usage between 20% and 80%, which seems fairly wasteful.
In early 2009 the code was changed to make it more like OnDemand, and the lower limit was (accidentally?) lowered to 10% (default). That "mistake" is still present in the 3.0 kernel so clearly no-one uses the conservative governor, but if they did I recommend setting the lower limit to 10% below the UPPER limit of 80% (or even 90%) to stand any chance of using less power than with on-demand.
Related
Right now I'm at 1.35GHz with Francos stock settings, so 700 for the minimum. Should I expect to see much of a loss in battery life? And what is the difference between the different governors? I could never find much info about them.
The OC itself dosent affect battery, it's how much time your phone is in whatever state(350, 700, 1350, etc..) also setting the minimum to 700 is either really good or really bad for battery, if you turn on your screen ever 5 minutes then it will be better to have it at 700 but if you only turn on your screen once every couple hours you will get much better battery with the absolute minimum. As for governors
Code:
interactive - Instead of sampling the cpu at a specified rate, the governor will scale the cpu frequency up when coming out of idle. When the cpu comes out of idle, a timer is configured to fire within 1-2 ticks. If the cpu is 100% busy from exiting idle to when the timer fires then we assume the cpu is underpowered and ramp to MAX speed.
smartass - Is an improved version of interactive governor
ondemand – Available in most kernels, and the default governor in most kernels. When the CPU load reaches a certain point (see “up threshold” in Advanced Settings), ondemand will rapidly scale the CPU up to meet demand, then gradually scale the CPU down when it isn't needed.
conservative – Available in some kernels. It is similar to the ondemand governor, but will scale the CPU up more gradually to better fit demand. Conservative provides a less responsive experience than ondemand, but can save battery.
performance – Available in most kernels. It will keep the CPU running at the “max” set value at all times. This is a bit more efficient than simply setting “max” and “min” to the same value and using ondemand because the system will not waste resources scanning for CPU load.
powersave – Available in some kernels. It will keep the CPU running at the “min” set value at all times.
userspace – A method for controlling the CPU speed that isn't currently used by SetCPU. For best results, do not use the userspace governor.
brazilianwax - Very agresive version of smartass
interactiveX - Tweaked Interactive governor by Imoseyon by adding more features like suspend/wake profile
ondemandX - Tweaked and ported from 2.6.38 base Ondemand governor by Imoseyon by adding more features like suspend/wake profile
This is taken from the lord module kernel from the desire HD forum as it has a list of many governors, you may have to try a couple governors until you find one that balances speed and battery life for your personal needs, on more governor on our devices is hotplug which will turn off one of the CPU cores when the screen is off.
A couple weeks ago, I installed SetCPU to help with battery life. It did great! But, I didn't see the amazing improvement that I thought I would.
So, I did some research and found out about Profiles. Profiles are settings that you can make that will be applied when certain conditions are met.
Below are the profiles that I have created on my Nitro. I have seen 11 to 12 hours of medium use from my phone with these settings. If you have any suggestions on changes, please let me know. I'd like to find the absolute best settings and share them for everybody.
Profile Name: Screen Off
Conditions: Screen Off
CPU Max: 384Mhz
CPU Min: 192Mhz
Governor: powersave
Priority: 90, Exclusive
Profile Name: Charging Any
Conditions: Charging Any
CPU Max: 1512Mhz
CPU Min: 192Mhz
Governor: ondemand
Priority: 85, Exclusive
Profile Name: In Call
Conditions: In Call
CPU Max: 810Mhz
CPU Min: 192Mhz
Governor: ondemand
Priority: 80, Exclusive
Profile Name: Battery <= 10%
Conditions: Battery <= 10%
CPU Max: 594Mhz
CPU Min: 192Mhz
Governor: conservative
Priority: 75, Exclusive
Profile Name: Battery <= 25%
Conditions: Battery <= 25%
CPU Max: 972Mhz
CPU Min: 192Mhz
Governor: conservative
Priority: 70, Exclusive
Profile Name: Battery <= 50%
Conditions: Battery <= 50%
CPU Max: 1242Mhz
CPU Min: 192Mhz
Governor: ondemand
Priority: 65, Exclusive
Profile Name: Battery <= 75%
Conditions: Battery <= 75%
CPU Max: 1350Mhz
CPU Min: 192Mhz
Governor: ondemand
Priority: 60, Exclusive
By setting the profiles base on battery percentage like that, you are sacrificing the speed to improve battery life. It works in some cases but has side-effect in many other cases:
- Firstly, for some tasks that requires high CPU, apparently you need more time at lower speed, so power consumption for CPU is the same but more power needed for longer screen on -> worse battery life
- Secondly, the more profiles you use, the longer it takes for SetCPU to decide and change CPU speed, so the responsiveness is lower
For you screen off profile, if you use powersave governor, your CPU always runs at min speed, so setting the max speed at 384 MHz is meaningless.
For me, the only profile I use is the screen off profile with min = 192MHz, max = 432MHz, governor = ondemand, so that my phone will wake up faster when there's a call (otherwise you will have to wait a little bit before you can sliding Answer/Reject)
noemtfj said:
By setting the profiles base on battery percentage like that, you are sacrificing the speed to improve battery life. It works in some cases but has side-effect in many other cases:
- Firstly, for some tasks that requires high CPU, apparently you need more time at lower speed, so power consumption for CPU is the same but more power needed for longer screen on -> worse battery life
- Secondly, the more profiles you use, the longer it takes for SetCPU to decide and change CPU speed, so the responsiveness is lower
For you screen off profile, if you use powersave governor, your CPU always runs at min speed, so setting the max speed at 384 MHz is meaningless.
For me, the only profile I use is the screen off profile with min = 192MHz, max = 432MHz, governor = ondemand, so that my phone will wake up faster when there's a call (otherwise you will have to wait a little bit before you can sliding Answer/Reject)
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Click to collapse
I haven't seen any responsiveness problems... And I'd actually like having a phone that I don't have to charge ever 3 hours over one that is unnecessarily fast.
mattman86 said:
I haven't seen any responsiveness problems... And I'd actually like having a phone that I don't have to charge ever 3 hours over one that is unnecessarily fast.
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Click to collapse
His point was that scaling your CPU back so significantly isn't necessarily going to give you better battery life, and may even make it worse. When the phone is running at a slower speed, it takes longer to do certain things, which means your CPU/screen will be turned on for longer. Of course it entirely depends on what you're doing on the phone.
I think you might get just as good battery life by using interactive 1.2GHz all the time. People assume governors like interactive will destroy their battery but you'd be surprised.
mattman86 said:
I haven't seen any responsiveness problems... And I'd actually like having a phone that I don't have to charge ever 3 hours over one that is unnecessarily fast.
Click to expand...
Click to collapse
If you have to charge your phone every 3 hours without SetCPU then I suggest you buy a new phone or new battery rather than playing with SetCPU
drumist said:
His point was that scaling your CPU back so significantly isn't necessarily going to give you better battery life, and may even make it worse. When the phone is running at a slower speed, it takes longer to do certain things, which means your CPU/screen will be turned on for longer. Of course it entirely depends on what you're doing on the phone.
I think you might get just as good battery life by using interactive 1.2GHz all the time. People assume governors like interactive will destroy their battery but you'd be surprised.
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Click to collapse
I don't do much with my phone in the way of heavy gaming or video watching. I am going off of the last couple days of having SetCPU enabled and getting almost 15 hours of medium use out of my phone.
noemtfj said:
If you have to charge your phone every 3 hours without SetCPU then I suggest you buy a new phone or new battery rather than playing with SetCPU
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Click to collapse
It was an arbitrary number.
Does anybody find this kind of post meant to make peoples phones better helpful? It seems like every time I post something that I personally have found to make the Nitro even more awesome gets a tone of comments basically telling me that none of it will ever work. I'm sure that if people would just try the things I post, they would be happy.
my setcpu setting-> uninstall
i found it did more harm than good. jd ultimate handling screen dimming&wifi with simple ondemand gov works much better for me.
scott0 said:
my setcpu setting-> uninstall
i found it did more harm than good. jd ultimate handling screen dimming&wifi with simple ondemand gov works much better for me.
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Click to collapse
That what I've heard also... But I found that JD ran my battery down in about 6 hours without me even touching it one day.
If you have any suggestions on settings for it, I'd love to give them a try.
mattman86 said:
That what I've heard also... But I found that JD ran my battery down in about 6 hours without me even touching it one day.
If you have any suggestions on settings for it, I'd love to give them a try.
Click to expand...
Click to collapse
yeah, i guess it's diff for everybody, just like the roms eh, some get great batt perf on 1 and sucky on another and someone has exactly opposite.
anyhoo, my jd ultimate settings are
Status
advanced profile
graphical notification->quickbox
Controls
wifi enabled->wifi preferred
brightness min 20% mid 45% max 150% (gotta get the most of this screen in the sunlight!)
light sensor fast
cpu min 192 mid 918 max 1512
governor ondemand
schedules
none, i also turned off night schedule as i have the phone plugged in during those hours.
triggers
Apps enabled
Configure->configure apps allow on during screen off->pandora
Location enabled
****************i find it makes a world of difference to give jd =>3 days to get it all right.
make sure setcpu is out of the way as well.
credit goes to stempox just thought id post here too..
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
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
Credit:http://forum.xda-developers.com/showthread.php?t=1736168
Extremely comprehensive, thank you so much for this, I feel I understand this world a little bit more after your post. Definitely makes me want to look a little deeper and experiment. Thanks!
Sent from my SAMSUNG-SGH-I747 using xda premium
theraffman said:
Extremely comprehensive, thank you so much for this, I feel I understand this world a little bit more after your post. Definitely makes me want to look a little deeper and experiment. Thanks!
Sent from my SAMSUNG-SGH-I747 using xda premium
Click to expand...
Click to collapse
Same way i felt when i read the post! totally gonna help me when choosing goveners i always chose ondemand because people said it was the best now that i know the real meaning of each Governor it helps a lot
Great article, been searching for this information for while now.
Great post, thanks.
I've been wondering about the msm governor just because it's said to use all features of the chip. Anyone have any more information about it? One thing that comes to mind is the mention of voltage scaling in the name.. Would that mess with or override custom undervolt settings?
Sent from my SAMSUNG-SGH-I747 using xda app-developers app
SmartassV2 my fav
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paulebe525 said:
SmartassV2 my fav
Sent from my E15i using xda app-developers app
Click to expand...
Click to collapse
ondemand or interactive for the win
Ktoonservative is just too good!
After reading all this: Which governor comes stock with our OEM JellyBean ROM? Although I may like the performance, I hate the battery-life.
My device is now rooted, but I just want to know which governor I'm leaving behind.
Anonymously_Unknown said:
After reading all this: Which governor comes stock with our OEM JellyBean ROM? Although I may like the performance, I hate the battery-life.
My device is now rooted, but I just want to know which governor I'm leaving behind.
Click to expand...
Click to collapse
I think it's the last one on the list
Sent from my SGH-I747M using xda app-developers app
This is not my work, i adjusted a bit (take several Governor out) , so all credits go to droidphile.
i will myself accept THANKS
Explanation of Different Governors
1. GOVERNORS
These are the 9 governors we're talking about.
1) Ondemand
2) Ondemandx
3) Conservative
4) Interactive
5) SmartassV2
6) Intellidemand:
7) Lagfree
8) Userspacce
9) Performance
1) Ondemand:
Default governor in almost all stock kernels. One main goal of the ondemand governor is to switch to max frequency as soon as there is a CPU activity detected to ensure the responsiveness of the system. (You can change this behavior using smooth scaling parameters, refer Siyah tweaks at the end of 3rd post.) Effectively, it uses the CPU busy time as the answer to "how critical is performance right now" question. So Ondemand jumps to maximum frequency when CPU is busy and decreases the frequency gradually when CPU is less loaded/apporaching idle. Even though many of us consider this a reliable governor, it falls short on battery saving and performance on default settings. One potential reason for ondemand governor being not very power efficient is that the governor decide the next target frequency by instant requirement during sampling interval. The instant requirement can response quickly to workload change, but it does not usually reflect workload real CPU usage requirement in a small longer time and it possibly causes frequently change between highest and lowest frequency.
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) Conservative:
A slower Ondemand which scales up slowly to save battery. The conservative governor is based on the ondemand governor. It functions like the Ondemand governor by dynamically adjusting frequencies based on processor utilization. However, the conservative governor increases and decreases CPU speed more gradually. Simply put, this governor increases the frequency step by step on CPU load and jumps to lowest frequency on CPU idle. Conservative governor aims to dynamically adjust the CPU frequency to current utilization, without jumping to max frequency. The sampling_down_factor value acts as a negative multiplier of sampling_rate to reduce the frequency that the scheduler samples the CPU utilization. For example, if sampling_rate equal to 20,000 and sampling_down_factor is 2, the governor samples the CPU utilization every 40,000 microseconds.
4) Interactive:
Can be considered a faster ondemand. So more snappier, less battery. Interactive is designed for latency-sensitive, interactive workloads. Instead of sampling at every interval like ondemand, it determines how to scale up when CPU comes out of idle. The governor has the following advantages: 1) More consistent ramping, because existing governors do their CPU load sampling in a workqueue context, but interactive governor does this in a timer context, which gives more consistent CPU load sampling. 2) Higher priority for CPU frequency increase, thus giving the remaining tasks the CPU performance benefit, unlike existing governors which schedule ramp-up work to occur after your performance starved tasks have completed. Interactive It's an intelligent Ondemand because of stability optimizations. Why??
Sampling the CPU load every X ms (like Ondemand) can lead to under-powering the CPU for X ms, leading to dropped frames, stuttering UI, etc. Instead of sampling the CPU at a specified rate, the interactive governor will check whether to scale the CPU frequency up soon after coming out of idle. When the CPU comes out of idle, a timer is configured to fire within 1-2 ticks. If the CPU is very busy between exiting idle and when the timer fires, then we assume the CPU is underpowered and ramp to max frequency.
5) 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.
6) 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.
7) 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.
8) Userspace:
Instead of automatically determining frequencies, lets user set frequencies.
9) Performance:
Sets min frequency as max frequency. Use this while benchmarking!
So, Governors can be categorized into 3/4 on a high level:
1.a) Ondemand Based:
Works on "ramp-up on high load" principle. CPU busy-time is taken into consideration for scaling decisions. Members: Ondemand, OndemandX, Intellidemand, Lagfree.
1.b) Conservative Based:
Members: Conservative,
2) Interactive Based:
Works on "make scaling decision when CPU comes out of idle-loop" principle. Members: Interactive, InteractiveX, Smartass, SmartassV2,
3) Weird Category:
Members: Userspace, Performance.
__________________________________________________ __________________________________________________ ____________
II) QUESTION TIME
Q. "Ok. Enough of explanations. Tell me which governor is for performance and which one is for battery life."
A. Tough question! smartassV2 for a balance between performance and battery. For light weight tasks. To get maximum performance, use a tweaked ondemand or conservative, but never complain about battery. NOTE: If you don't know how exactly to do it, stay away from it or you will end up complaining about battery drain!
Q. "Hey, almost forgot. How do i change governors?"
A. Best way is to use apps such as system tuner,android tuner,kernel tuner etc.
Q. "How do i know which governor is best for me?"
A. It depends on what you need and your daily usage pattern. Performance or battery. Better choose a governor that's balanced for battery/performance. Or tweak a governor to give performance an upper-hand as compared to battery. We can always re-charge the phone: In car when off to work, or overnight. But we can not recharge performance!
Q. "I can feel slight lags here and there with a governor. For ex: while scrolling through app drawer/vertically scrolling browser, etc. I really love this governor and don't tell me to use another governor. Can i diminish this lag?"
A. Hmm well, you can. Basically what we have to do is make the governor "poll" less often to scale-down cpu. Increase down-sampling-time of your governor (whichever parameter that corresponds to), so that the cpu will stay longer on a frequency before scaling down. This should eliminate the lag.
Q. "Even though i don't have too much uv/oc, once in a while; may be once in two weeks, i experience a freeze/lock/reboot. I'm using governor X. How do i solve this?"
A. Well, a random reboot/freeze once in a while signifies that we're android/ enthusiast. If everything go smooth as silk, what's the fun? We could use stock rom/kernel/governor and be happy. A rare reboot or freeze is nothing to worry about. Just restart the phone.
Q. "OK. I want to tweak these governors according to my usage pattern, because i'm not happy with the default behavior of these governors".
A. You can tweak the governors using an init.d script to echo suitable values into:
/sys/devices/system/cpu/cpufreq/name-of-active-governor/name-of-the-paramater-to-tweak
screen-on will not drain too much battery like you think!
HIT THE THANKS IF THIS INFORMATION WAS HELPFULL
Same exact thing can be found here http://forum.xda-developers.com/showthread.php?t=1369817
So I suggest you give droidphile a "Thanks" aswell
i was wondering how the governors work on our devices ~
Thanks for your shareing! it's really helpful!
jasperlin1996 said:
i was wondering how the governors work on our devices ~
Thanks for your shareing! it's really helpful!
Click to expand...
Click to collapse
On a single core cpu, smartass v2 is always recommended for performance/battery balance.
If you got a S4 Dual or S4 Quad device on JB rom, that is another story. On-demand or even interactive actually works well.
TheEndHK said:
On a single core cpu, smartass v2 is always recommended for performance/battery balance.
If you got a S4 Dual or S4 Quad device on JB rom, that is another story. On-demand or even interactive actually works well.
Click to expand...
Click to collapse
thanks for your recommend!
I DID NOT CREATE THE ORIGINAL LIST OF 20 GOVERNORS BUT I DID ADD MORE AND I DID TAKE THE TIME TO DOUBLE CHECK EACH INDIVIDUAL GOVERNOR TO MAKE SURE THEY WERE CORRECT...I MADE THIS SOLELY SO PEOPLE DONT HAVE TO GO BACK TEN PAGES TO SEE IT...a big thanks to rEcEivEr for the original thread/post I found and all the other original OP's.
If you feel any are missing or if there are new ones I missed please let me know and we'll add them....hope this helps because I see plenty of people asking.
So let's get to it...
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: Dyninteractive
30: Sakuractive (Thanks to Sandman-007)
31: Ktoonservative (Thanks to EniGmA1987)
32: Zen (Thanks to EniGmA1987)
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: Dyninterative
Similar to interactive in almost every way possible except it "dyn"amically adapts its own tunables and settings depending on system load
30: Sakuractive: This driver mimics the frequency scaling behavior in "on demand" but with several key differences. First is that frequency transitions use the CPUFreq table directly, instead of incrementing in a percentage of the maximum available frequency. Second "sakuractive" will offline auxillary CPUs when the system is idle, and online those CPUs once the system becomes busy again. This last feature is needed for architectures which transition to low power states when only the "master" CPU is online, or for thermally constrained devices
31: Ktoonservative
There is so much going on with this governor I'd rather have the makers explain it themselves....so here you go
http://forum.xda-developers.com/showthread.php?t=2032956
32: Zen
It's an FCFS (First come, first serve) based algorithm. It does not do any sorting. It uses deadlines for fairness, and treats synchronous requests with priority over asynchronous ones.