CPU Schedulers - Galaxy S II Q&A, Help & Troubleshooting

Siyah kernel allows changing the scheduler, so now that i can do it i'm wondering what's the difference (especially performance wise) between the different schedulers. Can anybody explain this here or point me to a good guide? Thanks.

If you ask in this newly made thread you would probably get your answer.
http://forum.xda-developers.com/showthread.php?t=1325831

Related

[Q] Difference between NoFills and Set CPU

I searched but haven't seen this question been asked before.
What is the difference between No-frills and Set CPU for over-clocking the android device.
What are the advantages or disadvantages when comparing the 2.
Thanks...
SetCPU has more features and is nice for people who know what they're doing. No-Frills is easy to use and is capable to set different I/O schedulers (which i don't think SetCPU is able to do). I'm using No-Frills since i don't need all the other stuff and it is working perfectly.
I have no idea about the difference between these two at a technical level though, but both are stable and high quality, so you can't go wrong.

[Q] Which governer to choose? CM7...

Can someone explain to me what are the differences between all the governors in cyanogenmod 7? Which one do you use and which is by your opinion the best for best performance?
Matekofski said:
Can someone explain to me what are the differences between all the governors in cyanogenmod 7? Which one do you use and which is by your opinion the best for best performance?
Click to expand...
Click to collapse
1.Google for android governors
2.read info on them
3.check which one suits you
4.Apply
governor is personal choice thats why you have options
Matekofski said:
Can someone explain to me what are the differences between all the governors in cyanogenmod 7? Which one do you use and which is by your opinion the best for best performance?
Click to expand...
Click to collapse
1. Governors are dependent on kernels, not ROMs. Here is a short, but solid explanation about the most famous governors:
http://forum.xda-developers.com/showthread.php?t=843406
2. I'm using the interactiveX and smartass governors (I switch frequently).
As explained above, the best for performance has to be the performance governor. But it's also the lousiest for battery life (sometimes 50% or more decrease compared to other governors).
3. http://lmgtfy.com/?q=cpu+governors+explained
thank to you both...you got a thanks button sori that i didn't google it it's ondemand now...looks like a good governer...and smartass too...
heres another good reading
http://forum.xda-developers.com/showthread.php?t=1242323

Resurrection Remix 1.9 Governor I/O

Hi all, now i'm using vr- lulzactive with 100-1200 and stock voltages can somowone teach me what is the best governor and i/o for this rom?
cfq/ondemand are usually paired with siyah kernel
AleDB said:
Hi all, now i'm using vr- lulzactive with 100-1200 and stock voltages can somowone teach me what is the best governor and i/o for this rom?
Click to expand...
Click to collapse
This is difficult to say, as it depends on your hardware, apps, settings, region, carrier and usage ... and what is "best" for you (best performance or best battery life).
So, you may have to check out the available governors and schedulers yourself.
Here is a very good thread about io schedulers and governors => http://forum.xda-developers.com/showthread.php?t=1369817
If you don't read it already and want to know more.

[ZIP]Flashable SIO Init.d Script + Optional Module Installation

So with the hubbub about io schedulers and stuff, I created two zips. One just creates an init.d script to force SIO to be the io scheduler on boot. The other installs the SIO module (thanks to batoo here for the module!) and creates an init.d that initiates and forces SIO on boot.
All the files are attached below, and you just have to flash them. There is no need to use an app to change the scheduler; I'd recommend telling the app to remove it's boot defaults.
Prerequistes
An unlocked Prime with CWM or TWRP is all that is really needed.
For those with a ROM/kernel that already has SIO as a module (ie Motley's kernel): use the sio-script zip.
For those with a ROM/kernel that does NOT have SIO incorporated: use the sio-script+module zip.
Credit goes to batoo who compiled and provided the SIO module. All I did was made it easily flashable without meddling in the terminal.
For those who are wondering why use this instead of an app to set SIO, there are a few reasons:
a) You can flash this with a ROM when you are starting from scratch.
b) Some apps don't set it while android is booting and only after you reach boot. This makes things significantly faster when your tablet is fresh started. And those that do set it with init.d probably take a little longer.
c) I don't really like an app messing with low-level boot instructions. That's just me.
Thanks st33med for giving noob like me an easy way to do this.
Quick question, how would i go about uninstalling this, would it be a matter of just deleting a script from init.d or would i need to do something else, the reaon i ask is that im having random reboots on andrrowooks latest rom while playing video over wifi, and im pretty sure ive narrowed it down to the enabling of sio through system tuner app.
Dont know if the issue is with the system tuner app or if the sio scheduler is conflicting with something else in my system, if so, i'd need to be able to uninstall, if that were the case
Prime seems to be playing nicely with cfq scheduler
Yeah just remove the 97siosched script or whatever it is called. It's in /system/etc/init.d/. If anything, noop would also give better performance now than CFQ with the motley kernel.
st33med said:
Yeah just remove the 97siosched script or whatever it is called. It's in /system/etc/init.d/. If anything, noop would also give better performance now than CFQ with the motley kernel.
Click to expand...
Click to collapse
Thanks man
Yeah ive been reading up on it, and been testing the shedulers while using cool tool, seems like noop likes to use the lower clock speeds more often when compared to cfq, i think in regard to battery, noop does a better job at using lower level clock speeds compared to others, seems to do a better job at keeping to a steady 102mhz while idle too
Am currently testing noop and and the conservative governer, but seems like there is minor performance hit, i dont think its a placebo, and im leaning towards it being mostly the governer, so ill leave it for a while, and set it back to interactive and see if i notice a performance boost
Theres quite a few governers and schedulers out there, wonder if we'll see any more of them head towards the primes way
Like banderos said, this is great, thanks for making this so easy to use!
st33med said:
Yeah just remove the 97siosched script or whatever it is called. It's in /system/etc/init.d/. If anything, noop would also give better performance now than CFQ with the motley kernel.
Click to expand...
Click to collapse
To clarify, you're suggesting noop + your init.d script for all kernels, or just if you're using motley kernel?
Komodo Rogue said:
Like banderos said, this is great, thanks for making this so easy to use!
To clarify, you're suggesting noop + your init.d script for all kernels, or just if you're using motley kernel?
Click to expand...
Click to collapse
Noop is a separate IO scheduler that comes as the default in the stock kernel. My script would replace the default io scheduler with SIO.
banderos101 said:
Thanks man
Yeah ive been reading up on it, and been testing the shedulers while using cool tool, seems like noop likes to use the lower clock speeds more often when compared to cfq, i think in regard to battery, noop does a better job at using lower level clock speeds compared to others, seems to do a better job at keeping to a steady 102mhz while idle too
Am currently testing noop and and the conservative governer, but seems like there is minor performance hit, i dont think its a placebo, and im leaning towards it being mostly the governer, so ill leave it for a while, and set it back to interactive and see if i notice a performance boost
Theres quite a few governers and schedulers out there, wonder if we'll see any more of them head towards the primes way
Click to expand...
Click to collapse
This makes sense. SIO is doing a little bit of sorting of database access in the stack, so it takes some CPU time. CFQ is the same, probably even more intensive since it's doing Round Robin on everything. Noop sticks by it's name, no operations. It's just a FIFO stack with io access.
We probably won't see anymore. There is deadline (which came with the ATP app, doesn't work well for us), bfq, vr, and a few others. But to be honest, on our device, SIO gives the best IO performance of them all but noop uses the least cpu time. CFQ is good for the other kernels besides motley's 3.0.6 kernel because they have low io and every program needs access at once. CFQ schedules and predicts which requests would take the most time and preempts them to another time in the close future. This allowed the browser to be smooth but load times would suffer a bit.
st33med said:
Noop is a separate IO scheduler that comes as the default in the stock kernel. My script would replace the default io scheduler with SIO.
Click to expand...
Click to collapse
*facepalm* I didn't realize SIO was an IO scheduler, I've never heard of that one before.
Here, have a good laugh at my expense Through the eyes of a technically oblivious tech enthusiast: Half the time I have no idea what the people around here are talking about, but I like flashable scripts, ESPECIALLY init.d scripts, because it seems like that's where all the action is. :highfive: I'll try using something in different combinations until I blindly stumble into a combination that I like. If it breaks, I fire up adb, and if it's faster than before and doesn't kill battery, then it's a keeper.
But I DO at least understand IO schedulers, cpu governors, and other basic things! And I agree with "c) I don't really like an app messing with low-level boot instructions. That's just me." I also prefer a flashable/delete-able script to some app that you have to keep installed.
st33med said:
We probably won't see anymore. There is deadline (which came with the ATP app, doesn't work well for us), bfq, vr, and a few others. But to be honest, on our device, SIO gives the best IO performance of them all but noop uses the least cpu time. CFQ is good for the other kernels besides motley's 3.0.6 kernel because they have low io and every program needs access at once. CFQ schedules and predicts which requests would take the most time and preempts them to another time in the close future. This allowed the browser to be smooth but load times would suffer a bit.
Click to expand...
Click to collapse
Does any of that change if you're using a good SD card for swap space? I'm getting one (for free!) this week, and wanted to try making a swap space partition.
Komodo Rogue said:
Does any of that change if you're using a good SD card for swap space? I'm getting one (for free!) this week, and wanted to try making a swap space partition.
Click to expand...
Click to collapse
I don't think Android would like using the SD card as swap. It's slower than the eMMC inside the machine. I wouldn't worry about swap, we have a gig of DDR2 memory and motley includes swap to the MMC card already. I don't know about IO schedulers for external memory (I think there are controllers on the card itself that do the work so no need for IO schedulers for them), but the IO scheduler we set only applies for internal memory.
st33med said:
I don't think Android would like using the SD card as swap. It's slower than the eMMC inside the machine. I wouldn't worry about swap, we have a gig of DDR2 memory and motley includes swap to the MMC card already. I don't know about IO schedulers for external memory (I think there are controllers on the card itself that do the work so no need for IO schedulers for them), but the IO scheduler we set only applies for internal memory.
Click to expand...
Click to collapse
I am actually looking for improve the perf of the prime of my wife. Talking about the swap, Motley use Zram that create a swap on the RAM directly. From my experience on my HTC Sensation using swap on my SD provide a better experience for multitasking and permit to have a bigger swap that perfectly fit for heavy use. I am just wandering if it's possible to partition the internal memory without unlock the bootloader.
bASKOU said:
I am actually looking for improve the perf of the prime of my wife. Talking about the swap, Motley use Zram that create a swap on the RAM directly. From my experience on my HTC Sensation using swap on my SD provide a better experience for multitasking and permit to have a bigger swap that perfectly fit for heavy use. I am just wandering if it's possible to partition the internal memory without unlock the bootloader.
Click to expand...
Click to collapse
Nope, you can't change the internal partition scheme without unlocking it.

[Q] Best Combination of Governors and I/O Schedulers for Every Need

To the experts, could you please provide us good combinations of CPU governors and I/O schedulers for every need, like for saving battery consumption or for good performance for lww and other same devices?btw im using CM10 wiht LuPus kernel in my LWW. thanks in advance!
Governor - I/O Scheduler
ironhide3.2 said:
To the experts, could you please provide us good combinations of CPU governors and I/O schedulers for every need, like for saving battery consumption or for good performance for lww and other same devices?btw im using CM10 wiht LuPus kernel in my LWW. thanks in advance!
Governor - I/O Scheduler
Click to expand...
Click to collapse
You should have checked this first - http://forum.xda-developers.com/showthread.php?t=1989824
It has a detailed description for many governors and i/o schedulers.

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