Database Develop

[Q] [Kernel dev] CPU frequency scaling overhead

Hi, I have a question that I hope some experienced kernel developers can help me with:
When a dynamic scaling CPU governor is used, will the number of defined CPU frequency steps in the kernel affects the performance of frequency scaling?
In other words, when a CPU scales from a low frequency to a high frequency, will a higher amount of intermediate frequency steps in between them slows down the ramping up of CPU frequency?

cleekee said:
Hi, I have a question that I hope some experienced kernel developers can help me with:
When a dynamic scaling CPU governor is used, will the number of defined CPU frequency steps in the kernel affects the performance of frequency scaling?
In other words, when a CPU scales from a low frequency to a high frequency, will a higher amount of intermediate frequency steps in between them slows down the ramping up of CPU frequency?
Click to expand...
Click to collapse
It depends on the governor pretty much... Some governors ramp up step-by-step. Some will take a big jump. You'd have to look at your governor to decide.

pulser_g2 said:
It depends on the governor pretty much... Some governors ramp up step-by-step. Some will take a big jump. You'd have to look at your governor to decide.
Click to expand...
Click to collapse
I see. Thank you!

Post your SetCPU / No Frills Settings (governor, min/max frequency, i/o scheduler)

Post your SetCPU / No Frills Settings (governor, min/max frequency, i/o scheduler)
Share your SetCPU or No Frill CPU settings .. You can share the following things..
Minimum and Maximum frequency
Governor used
I/o scheduler used
Profiles (if any)

I, myself am using...
Governor = SmartassV2
Max freq. = 806 MHz
Min freq. = 122Mhz
Scheduler - sio
Profiles = None

added a heat profile which turns on when the temp is over 35°C and sets the MHz to 320-600
Had some reboots because of the heat these days :S
Sent from my HTC Desire C using xda app-developers app

I have no schedule and no profiles
Sent from my HTC Desire C using xda premium

smoza said:
I have no schedule and no profiles
Sent from my HTC Desire C using xda premium
Click to expand...
Click to collapse
Pon de mínimo 320-480

Perfect balance..
Max 700
Min 100
Smartassv2
Max 850 while playing games
And a heat profile
Using cm10 and NOPE

aashay960 said:
Perfect balance..
Max 700
Min 100
Smartassv2
Max 850 while playing games
And a heat profile
Using cm10 and NOPE
Click to expand...
Click to collapse
What is a heat profile?

LaKsHaY1997 said:
What is a heat profile?
Click to expand...
Click to collapse
If battery temperature more than 39 C, max frequency to 400..
Thats what I use

aashay960 said:
If battery temperature more than 39 C, max frequency to 400..
Thats what I use
Click to expand...
Click to collapse
If battery temp is over 39 C I shove it in the freezer !!
I've always insisted performance/sio is best . After being literally forced screaming and kicking to try his preferred settings I now like interactive/row for daily and performance/deadline for benching

whoamigriffiths said:
If battery temp is over 39 C I shove it in the freezer !!
I've always insisted performance/sio is best . After being literally forced screaming and kicking to try his preferred settings I now like interactive/row for daily and performance/deadline for benching
Click to expand...
Click to collapse
I use these settings for daily use not for benchmarking (which I RARELY do). So according to you what should be a comfortable temperature to set? Also, does the country make a difference? If it does, the climate in india is very hot right now
Performance/sio = Bad battery life + Frequent overheating?? Is this true?

aashay960 said:
I use these settings for daily use not for benchmarking (which I RARELY do). So according to you what should be a comfortable temperature to set? Also, does the country make a difference? If it does, the climate in india is very hot right now
Performance/sio = Bad battery life + Frequent overheating?? Is this true?
Click to expand...
Click to collapse
I imagine country has an awful lot to do with the cpus temp . I'm in the UK and I really don't recall ever going over 38 degrees C (more like 36)
And yes performance/sio will be bad battery life cos if its my phone its ramped to 828min /828 max and being tortured for 12 hours at a time
as I said in the uk I've never had issues with overheating

whoamigriffiths said:
I imagine country has an awful lot to do with the cpus temp . I'm in the UK and I really don't recall ever going over 38 degrees C (more like 36)
And yes performance/sio will be bad battery life cos if its my phone its ramped to 828min /828 max and being tortured for 12 hours at a time
as I said in the uk I've never had issues with overheating
Click to expand...
Click to collapse
I've tried different settings and 39 is the point where it starts to 'feel' hot. So then setcpu works its magic and i stop working if its not impotant, screen off, and then I'm back

I live in Ireland and today for the first time ever I got a SetCpu notification because of overheating ha, although it was a hot day
Sent from my HTC Desire C

DillaDawg said:
I live in Ireland and today for the first time ever I got a SetCpu notification because of overheating ha, although it was a hot day
Sent from my HTC Desire C
Click to expand...
Click to collapse
SetCpu gives notifications? Didn't knew that.

This has been my setup for a while now:
SetCPU:
Min/Max: 75/750 MHz
Governor: Lulzactive
I/O Scheduler: row
Profiles:
a) 100 priority: Screen Off: 200 Min-300 Max: Lulzactive: row
b) 99 priority: Charging: 600 Min-750 Max: Lulzactive: row
My CPU can't handle over 750 Mhz... but I really don't need much CPU speed anyway

i'm quite new to these things with the no-frills app. I need someone who can tell me which options are best for saving up battery while still being able to do some basic stuff without any effort from the device (and to play some games from time to time ). I have no idea what all of the schedulers do
here they are if someone can explain what each does :
abyssplug
ondemandq
lagfree
lazy
smartassv2
interactivex
pegasusq
hotplug
conservative
userspace
powersave
lionheart
ondemand
performance
and the things at the right :
noop
deadline
row
cfg
btw today I flashed goldenkernel v2 on my s3 mini (mainly because of the ability to have more battery life), but don't know what setup to make in no-frills in order to save battery and keep my phone with good performance.
Please HELP !!

koragg97 said:
i'm quite new to these things with the no-frills app. I need someone who can tell me which options are best for saving up battery while still being able to do some basic stuff without any effort from the device (and to play some games from time to time ). I have no idea what all of the schedulers do
here they are if someone can explain what each does :
abyssplug
ondemandq
lagfree
lazy
smartassv2
interactivex
pegasusq
hotplug
conservative
userspace
powersave
lionheart
ondemand
performance
and the things at the right :
noop
deadline
row
cfg
btw today I flashed goldenkernel v2 on my s3 mini (mainly because of the ability to have more battery life), but don't know what setup to make in no-frills in order to save battery and keep my phone with good performance.
Please HELP !!
Click to expand...
Click to collapse
READ HERE: http://bit.ly/1dwdKpf
By the way, next time post in your device's forum, this is for HTC Desire C.

atomomega said:
READ HERE: http://bit.ly/1dwdKpf
By the way, next time post in your device's forum, this is for HTC Desire C.
Click to expand...
Click to collapse
thanks and sorry about the post but i completely forgot to check out if this article is for my s3 mini. when i found it i was so happy that i could ask my question here that forgot about everything else

my config
i am using xperia m dual(C2004) below are my config

karthikgoud said:
i am using xperia m dual(C2004) below are my config
Click to expand...
Click to collapse
Actually this is a desire c forum.. But I'll post mine too (as a old desire c user)
Xperia sp (c5303) on cm11
Sent from my C5303 using XDA Free mobile app

overclocking

Is there any way to overclock this device's cpu or gpu or even change governors?

revery0 said:
Is there any way to overclock this device's cpu or gpu or even change governors?
Click to expand...
Click to collapse
I hope this will help you: http://forum.xda-developers.com/asc...7en-rom-v1-0-emui-2-3-4-4-2-23-10-14-t2916016

This rom has modified governors and does not gives you the ability to change anything or adjust the cpu speed...

revery0 said:
Is there any way to overclock this device's cpu or gpu or even change governors?
Click to expand...
Click to collapse
We don't have a kernel that supports overclocking or has different governors implemented, so that's a no...

GawDroid said:
We don't have a kernel that supports overclocking or has different governors implemented, so that's a no...
Click to expand...
Click to collapse
Actually we do.. the stock kernel allows to overclock ( optimum performance power plan )

revery0 said:
Actually we do.. the stock kernel allows to overclock ( optimum performance power plan )
Click to expand...
Click to collapse
AFAIK, the power plan modifies the cpu frequency stepping, but still it doesn't allow surpassing the maximum CPU frequency of 1795 MHz.
And the only governor in our kernel is a version of hotplug.
Here's how it works in my understanding:
Quote: The “hotplug” governor scales CPU frequency based on load, similar to “ondemand”. It scales up to the highest frequency when “up_threshold” is crossed and scales down one frequency at a time when “down_threshold” is crossed.
The powerplan can modify the up- and down- threshold steps (so the device can use max frequency sooner and stay on higher frequencies longer), but that doesn't affect max frequency at all.

Hi!
This scripts is not overclock, but change/lock clock speed.
You need root, and any Script runner app.
Ddr_gpu=lock max speed ddr and gpu
ddr_gpu_cpu=lock max speed ddr, gpu and cpu
ddr_gpu_cpu_4core=lock max speed ddr, gpu, cpu and lock 4 core cpu
ddr_gpu_cpu_core_4core_stock=revert all to stock.
This scripts not pernement, if you restart the phone, all settings revert back to stock.
Ps: please when you download this files, delete the .zip.

No-Frills CPU Control
This apk controls your CPU on device.
Sent from my HUAWEI P7-L07 using XDA Free mobile app

Ziółek said:
No-Frills CPU Control
This apk controls your CPU on device.
Click to expand...
Click to collapse
Won't allow overclocking max frequency either... Just increasing min freq, and decreasing max freq.
Pretty much useless on P7, since we only have 1 governor and 3 I/O schedulers to chose from.

GawDroid said:
Won't allow overclocking max frequency either... Just increasing min freq, and decreasing max freq.
Pretty much useless on P7, since we only have 1 governor and 3 I/O schedulers to chose from.
Click to expand...
Click to collapse
Where I wrote that this app allowed overclocking ? It control CPU min and max frequency but only in factory fixed range.

Ziółek said:
Where I wrote that this app allowed overclocking ? It control CPU min and max frequency but only in factory fixed range.
Click to expand...
Click to collapse
Easy, Ziółek You never said it did.
However, since No-Frills doesn't do any good in the terms of overclocking, why posting about it in the overclocking thread
Would you agree?
pozdro z Wro

GawDroid said:
Easy, Ziółek You never said it did.
However, since No-Frills doesn't do any good in the terms of overclocking, why posting about it in the overclocking thread
Would you agree?
pozdro z Wro
Click to expand...
Click to collapse
Agree I referred only to the post with scripts
pozdro z Wawy :good:

No-frills not work correctly on p7...can't lock max speed and 4cpu clock, and can't lock gpu and ddr clock...
But this scripts do.
Try and check with cooltool.

Nexus 5 Voltage How Low Can You Go.

When I start my day with my phone my ultimate goal is to get the most out of my battery. I have a Nexus 5 which is great phone but one downside is that the battery which is 2300mah can barely get you through the day. One way to help this issue is to under volt your CPU, the nexus 5 has a snapdragon 800 CPU clocked at 2.26GHz which is power CPU but at times it can run a bit hot and use more juice than it needs. By Under Volting your CPU your device will run much cooler without losing performance. (Warning if you go too low with the voltages your device will freeze and randomly reboot. ). The voltages than the nexus 5 ships with are a bit high I've been able to under volt up to -75mah without losing any performance however your experience may be different. To under-volt your device you need to have a rooted phone with a custom kernel installed. Franco, ElementalX, and Codeblue are few a few of the many kernels you can use with the nexus 5. I've been using ElementalX as my kernel for a while now, although Franco is also a good one. I use the ElementalX kernel app to manage my voltages, its a paid app but its definitely worth it. you could also use the Kernel tweaker app to manager voltages as well. I've set the governer to elementalx and i set the max cpu freq to 1574MHz, and the max screen off frequency is set to 729MHz. Don't go to extremes take small steps. Please let us know your results here.
This is what i have so far.
300MHz = 650mV
422MHz = 650mV
652MHz = 700mV
729MHz = 720mV
883MHz = 740mV
960MHz = 750mV
1036MHz = 760mV
1190MHz = 780mV
1267MHz = 790mV
1497MHz = 830mV
1574MHz = 845mV
1728MHz = 875mV
1958MHz = 945mV
2265MHz = 1000mV
Edit:
my pvs is 2
300MHz = 650mV
422MHz = 650mV
652MHz = 700mV
729MHz = 710mV
883MHz = 730mV
960MHz = 740mV
1036MHz = 750mV
1190MHz = 770mV
1267MHz = 780mV
1497MHz = 835mV
1574MHz = 840mV
1728MHz = 875mV
1958MHz = 965mV
2265MHz = 975mV

I have franco kernel, I will try your settings, Report later !

Avg sot ?

doctor_droid said:
Avg sot ?
Click to expand...
Click to collapse
I can manage about 5-6 hours but Ive made other changes as well I haven't only undervolted

apatel321 said:
I can manage about 5-6 hours but Ive made other changes as well I haven't only undervolted
Click to expand...
Click to collapse
Anything above 5hrs sot is good

doctor_droid said:
Anything above 5hrs sot is good
Click to expand...
Click to collapse
I keep my brightness at the minimum with adaptive brightness enabled also my max CPU is set to 1190MHz, I do mostly web browsing I

cranknet said:
I have franco kernel, I will try your settings, Report later !
Click to expand...
Click to collapse
Just wondering which governor are you using with the Franco kernel.

apatel321 said:
I keep my brightness at the minimum with adaptive brightness enabled also my max CPU is set to 1190MHz, I do mostly web browsing I
Click to expand...
Click to collapse
That is sweet do you live in total dark and browsing html pages LOL

apatel321 said:
Just wondering which governor are you using with the Franco kernel.
Click to expand...
Click to collapse
I'm using Interactive.

nedooo said:
That is sweet do you live in total dark and browsing html pages LOL
Click to expand...
Click to collapse
Most of the time adaptive brightness keeps the brightness at the right level however I I do wish you could adjust the sensitivity of it

[update] I was experiencing some random reboots
It wasn't as stable as it should be

apatel321 said:
Most of the time adaptive brightness keeps the brightness at the right level however I I do wish you could adjust the sensitivity of it
Click to expand...
Click to collapse
Sorry for my sarcasm
BTW back to topic I use Code_Blue kernel and I lower voltage -35 wirh Synapse and my voltage is from 740mV for 300MHz to 990mV for 2265MHz

nedooo said:
Sorry for my sarcasm
BTW back to topic I use Code_Blue kernel and I lower voltage -35 wirh Synapse and my voltage is from 740mV for 300MHz to 990mV for 2265MHz
Click to expand...
Click to collapse
You should be able to go as low as 650mV for both 300MHz and 422MHz., without experience unstable behavior.

pvs bin?

varuntis1993 said:
pvs bin?
Click to expand...
Click to collapse
Mine showed 3 on synapse.

varuntis1993 said:
pvs bin?
Click to expand...
Click to collapse
its 2

Just remember in a couple weeks if you notice stability issues or your phone rebooting, it's probably because of these changes.
Personally I value 100% stability, and I'm already able to achieve the same battery lifeout of default clocks and voltages as well as stock ROM and kernel. Such as these 5-6 hour SoT examples using 40% Adaptive Brightness.
http://imgur.com/a/vQpoz
http://imgur.com/a/sdx3a
Also I think you'll find lowering the voltages by 5-10% doesn't make a noticeable difference in battery usage, thought it should run cooler and throttle less.

apatel321 said:
You should be able to go as low as 650mV for both 300MHz and 422MHz., without experience unstable behavior.
Click to expand...
Click to collapse
Going to give this a try. I've had good success undervolting other handsets.

With latest code blue and adiutor app cannot set 650mv for 300mhz and 422mhz, lowest i can go is 700mhz not sure why though. Thank you anyway, I'm trying this out.
Enviado desde mi Nexus 5

It's the kernel the lowest you can go with code blue is 700

HUGE RENDERING, FPS and SMOOTHNESS improvement on OOS.

I don't know if it works on OOS versions but it does, on the OB12. You need to be rooted to be doing this.
Lower the input boost to 1036 on the big and 556 on the small first. Now, change the governor of the big cluster to conservative and the small to ondemand or conservative , benefit!
To see the improvement in FPS, you need to go to developer options and switch on profile GPU rendering. For those who didn't understand this: lower the graph is, higher the fps. Hit thanks if helped

Where to change these settings?

Any kernel manager would do. I'd recommend kernel aduitor

chinmai560621 said:
Any kernel manager would do. I'd recommend kernel aduitor
Click to expand...
Click to collapse
Just change the option of GPU GOVERNER to simple_on demand one from the above mentioned app. It will work smooth.. works for me..:good:?

ashokspidy said:
Just change the option of GPU GOVERNER to simple_on demand one from the above mentioned app. It will work smooth.. works for me..:good:?
Click to expand...
Click to collapse
I'd recommend to leave it on msm-adreno.

What if I'm on RR 5.8.2 and ElementalX? I have ondemand governor option for little but don't have conservative for big cluster.

karliyo said:
What if I'm on RR 5.8.2 and ElementalX? I have ondemand governor option for little but don't have conservative for big cluster.
Click to expand...
Click to collapse
This is exclusive for OOS. In fact, the interactive is supposed to be better than the rest but it's not the case on OOS which is why I made this thread.

chinmai560621 said:
This is exclusive for OOS. In fact, the interactive is supposed to be better than the rest but it's not the case on OOS which is why I made this thread.
Click to expand...
Click to collapse
Oh alright. Little governor ondemand seems quite fine right now.
By the way, are both governors interactive by default?

karliyo said:
Oh alright. Little governor ondemand seems quite fine right now.
By the way, are both governors interactive by default?
Click to expand...
Click to collapse
Has to be. Unless you use blu_spark kernel. It uses blu_activ.

How do these changes affect the battery life?

chinmai560621 said:
Has to be. Unless you use blu_spark kernel. It uses blu_activ.
Click to expand...
Click to collapse
You mean interactive and not blu_active?
I do recommend you guys taking a look at AKT.. There are alot of peformance oriented and balanced profiles that are already better with smoothness then stock.. Also Franco has some magic with stock settings!

chinmai560621 said:
I don't know if it works on OOS versions but it does, on the OB12. You need to be rooted to be doing this.
Lower the input boost to 1036 on the big and 556 on the small first. Now, change the governor of the big cluster to conservative and the small to ondemand or conservative , benefit!
To see the improvement in FPS, you need to go to developer options and switch on profile GPU rendering. For those who didn't understand this: lower the graph is, higher the fps. Hit thanks if helped
Click to expand...
Click to collapse
Hi friend, shall I change both values of big and small? I mean maximum and minimum?

Same, cant find where to change the input values for those two.

rOck4n said:
Same, cant find where to change the input values for those two.
Click to expand...
Click to collapse
You'll see input boost in the bottom section of CPU in kernel adiutor. Core 1- 1036, core 3 -556 is what you've to do. It'll be 1324 default on both. I'm suggesting that for slightly better battery life

MarcTremonti said:
How do these changes affect the battery life?
Click to expand...
Click to collapse
Lower SOTs are obvious, but to what degree is what matters. As far as I see, it's not that much.

GUYS, I recommend not to use this anymore. Oneplus has a reason to not release the kernel with conservative on . This is because conservative is not optimized for battery while interactive is. If interactive weren't optimized for battery, it'd be better than conservative for sure. I get only 4 hr sot on conservative but 5.5 on interactive. Though this is not placebo, it has a negative impact on SOT .

When I change big cluster to conservative, those cores will always stay above 2 GHz, as shown in Kernel Adiutor.

chinmai560621 said:
GUYS, I recommend not to use this anymore. Oneplus has a reason to not release the kernel with conservative on . This is because conservative is not optimized for battery while interactive is. If interactive weren't optimized for battery, it'd be better than conservative for sure. I get only 4 hr sot on conservative but 5.5 on interactive. Though this is not placebo, it has a negative impact on SOT .
Click to expand...
Click to collapse
The thread is about more performance and you're discussing battery life....of course it will have a lower battery life, the question is are you happy when your quad-core phone stutters....

chinmai560621 said:
You'll see input boost in the bottom section of CPU in kernel adiutor. Core 1- 1036, core 3 -556 is what you've to do. It'll be 1324 default on both. I'm suggesting that for slightly better battery life
Click to expand...
Click to collapse
Got it, thank you. I did notice a slightly battery improvement after two cycles.

Little investigation..
chinmai560621 said:
GUYS, I recommend not to use this anymore. Oneplus has a reason to not release the kernel with conservative on . This is because conservative is not optimized for battery while interactive is. If interactive weren't optimized for battery, it'd be better than conservative for sure. I get only 4 hr sot on conservative but 5.5 on interactive. Though this is not placebo, it has a negative impact on SOT .
Click to expand...
Click to collapse
Good you realised that.. I did a little investigation on your tweak.. Apparently setting governor to conservative locks the frequency of big cluster to max possible, usually above 2 ghz and it will step down slowly ( by slow I mean really slow like 1-2 seconds). Thus causes you to have very less render times on gpu profile as shown in the xda portal post.. I opened up ex kernel manager and observed same freq in higher range.
After some time I just changed governor to interactive and changed minimum freq of big cluster to 2 ghz.. I observed the same render times as situation as time when conservative was set as governor...
So this tweak is nothing but type of placebo since ramping up freq can lead to faster processing
Edit.: Couple of people on xda portal have said the same.. I didn't check it..