Develop Bugs

[DISCUSSION] The poor IO performance of the SGS

This thread is for the discussion about the bounty and how to fix the poor IO performance
--> Bounty thread <--

A shellscript that do
-mount partition
-make a tarball of all data from this partion
-copy this tarball to /sdcard
-umount partion und format to new fs
-mount partion with new fs
-untar the tarball from /sdcard
for all relevant partion should be simple to write. After this the init.rc must modified to mount the new fs and not the old rfs. If the file is the same for all eclair firmwares, only this one has to change. The shellscript move the init.rc to init.rc.bak and copy the modified version.
This script can be started from an update.zip(I dont know if this possible). Or modify a recovery image, to start the script by a menu selection(this is possible).
I think this can be provide a simple solution for endusers. Unclear for me is why samsung use the rfs. This filesystem is optimized for flashdisks. It sounds like the internal nand has no wearleveling and a not flash optimized filesystem can damage the internal nand by rapid use to quickly.
I plan to test out how an external sdcard can provide the full os, not only partial like the speedhack. The init.rc file must modified to switch directly after start to the init.rc file on external sdcard. The init.rc from external sdcard start the the system from external sdcard. This variant reduce the modification on the phone and if the flashdisk is dead, the SGS is not a brick.
gr, Steffen from Germany

What types of file systems does the stock kernel support? Can it boot from ext2 as it can from this rfs?
Also: apparently the Nexus One uses the YAFFS2 file system for its root file system, which is made for use on NAND memory. Although it's probably easier to get kernel, tools and scripts to work for an ext2 based solution, we should probably look at getting a YAFFS2 fix eventually for best reliability.

I put up a quick guide over here which uses the playlogo hack. It's working perfectly for me and my phone is as smooth as butter!
http://forum.xda-developers.com/showpost.php?p=7571976&postcount=161

bub181 said:
I put up a quick guide over here which uses the playlogo hack. It's working perfectly for me and my phone is as smooth as butter!
http://forum.xda-developers.com/showpost.php?p=7571976&postcount=161
Click to expand...
Click to collapse
What firmware are you on?

As far as i remember, it is possible to ajust the times to which the filesystem (ext2,3,4?) syncs... If you increase that time, i would mean less writings to the nand - which again makes it last longer..
EDIT: spell correction.

andrewluecke said:
I'm concerned about this. People who are contributing to this bounty should consider:
1) Who decides if the fix is done? How exactly are you going to test? You can cause lag on every phone if you open enough crap, so how you going to test this? Or will you use a synthetic benchmark such as Quadrant?
2) Who verifies that the fix is safe. It's all good that you might end up with a solution where all lag is gone. But you might end up with a solution with no wear levelling which sucks up battery power because whenever the phone is idle it's performing online defragmentation.
3) Is battery life a consideration?
4) Remember, erasing flash memory also has a cost, which is why early SSD drives without trim slowed down a lot after a while, because they wouldn't erase it when the system was idle. So the fastest solution might be fast initially, but might write a lot of excess crap, which could affect long term results. Hence (1).
Before anyone explores a solution for this bounty, these questions must be answered, because disturbingly, I haven't heard 1 mention of SLC, Movinand or write cycle yet. I've only heard "RFS".
Furthermore, I've only heard "EXT", not "profiling tool" (has anyone actually profiled applications yet to isolate where the slowdown is). So, I think this bounty needs a bit more discussion.
It might also just be something simple, such as implementing something similar to Trim potentially (I myself aren't familiar with the architecture). Yes I want a solution too, but I want to ensure it's done properly.
Click to expand...
Click to collapse
We need to decide on how to test it!

My experience with lag
Hi Guys
The lag can be observed in two places:
1- While moving between windows in system apps (e.g. settings) or 3rd party apps (games, utilities). This lag keeps fluctuating, so sometime you would get it and sometimes you would not, and I DONT KNOW WHY
The above is definitely due to inefficient coding by Samsung
2- Second type of lag is when you try to start an App and you need to wait for a couple of seconds between the time you click on the App icon till the time you actually get a response (the App loads)
The above is inefficient coding by either Samsung or 3rd party App programmers. I DONT KNOW WHO
I believe that the first one could be solved, but there is no way in solving the second one as apparently the Android market does not enforce rules on 3rd pary programmers to make sure their apps are up to standard
On the other hand, i noticed that the second type of lagging was non-existant in Apple Store even for large applications/games because they enforce certain coding standards (as compared to Asphalt5 which is a big game and lags like hell when you want to load it)
Does what i am saying make sense, or is it that improving or patching the Samsung OS itself will solve all lagging problems for both the firmware and 3rd party Apps ????????????????

Apple has codingstandards that eliminates loading time? Thats impressive...
Sent from my GT-I9000 using XDA App

may I suggest contacting XDA user TKirton over on the Hero CDMA portal. He's written a fantastic implementation of Apps2sd which works across many platforms. He has great insight and knowledge of Android and linux filesystems and may be a good person to get on board with this.

Ramdisk/swap

What are the possibilities of using our 2gb of ddr program storage and re allocating it as system ram?
Even if it isn't pure flash (slow speed) I imagine it would be better then nothing, we could always store programs on the sdcard.
Sent from my GT-I9000 using XDA App

android53 said:
What are the possibilities of using our 2gb of ddr program storage and re allocating it as system ram?
Click to expand...
Click to collapse
very good, this post actually explains how to make a swap file (on /cache which is fast nand!).
if you want a swap partition you could a) use part of the 2gb /data partition for a new swap partition which you create in a project-voodoo like manner -> not very easy to do as you would have to repartition /data before boot OR b) just make a 2nd partition on your external sd card to swap on. a lot of people (me included) actually did this with their htc magic.
but to be honest i don't think that you will gain any speed improvements with this, on the contrary your system will be slower an more laggy... i found swap even worse on the magic with ~90mb of user-available-ram. if you want to try it nevertheless, it think the swap file on /cache would be a good start!

jodue said:
very good, this post actually explains how to make a swap file (on /cache which is fast nand!).
if you want a swap partition you could a) use part of the 2gb /data partition for a new swap partition which you create in a project-voodoo like manner -> not very easy to do as you would have to repartition /data before boot OR b) just make a 2nd partition on your external sd card to swap on. a lot of people (me included) actually did this with their htc magic.
but to be honest i don't think that you will gain any speed improvements with this, on the contrary your system will be slower an more laggy... i found swap even worse on the magic with ~90mb of user-available-ram. if you want to try it nevertheless, it think the swap file on /cache would be a good start!
Click to expand...
Click to collapse
If we go for b, will the sgs detect and use the swap partition or do we need to do something else.. I still use my htc magic along side my sgs
Sent from my GT-I9000 using XDA App

i have tried using a swap file, but i didnt c any improvements, and the usage was about 500kb only

I recall that on liquid we managed to use a ramzswap module, which fakes a zipped swap partition in ram. It causes cpu to work a bit more, but it was still efficient.

Elvoski said:
If we go for b, will the sgs detect and use the swap partition or do we need to do something else.. I still use my htc magic along side my sgs
Click to expand...
Click to collapse
you would have to repartition our external sd to have a second (linux swap) partition.
then use mkswap to set the partition up and after that call swapon. swapon has to be redone every time you restart but you could place it in a playlogos1 script to automate that.
captive said:
I recall that on liquid we managed to use a ramzswap module, which fakes a zipped swap partition in ram. It causes cpu to work a bit more, but it was still efficient.
Click to expand...
Click to collapse
compcache?! ... i guess this would also be a good trade off for our galaxy s because the cpu is definitely not the bottleneck here...
btw. a good read about swap & compcache from the cyanogenmod wiki: swap & compcache

android53 said:
What are the possibilities of using our 2gb of ddr program storage and re allocating it as system ram?
Sent from my GT-I9000 using XDA App
Click to expand...
Click to collapse
Bad, bery bad idea, MoviNand is not in any way releated to DDR. It's waaaay slower.
Also, RAM is designed for virtually unlimited data read/write counts.
NAND memory is not.
What would be the benefit of using swap space? Nothing. Data is being read/written in filesystem in the end. No improvement in performance. (It could be seriously degraded).
This behavior is totally against Android core design principles. Android doesnt use swap because it doesnt need to. Programs not fitting into "RAM" are being closed with their state remembered. When program is re-launched it is loaded from filesystem and its state is being restored.
If we had "swap" space, it would become really messy. Just imagine:
System wants to close program X, resident in swap, it needs to:
- restore program from swap to RAM (talk about additional ram needed)
- close program, resulting writing state to FS.

i was talking about this sort of thing with Ryza and Voodoo guy they said it was too much work
i'm forward with the idea of using a Swap drive in RAM or external SD
to prevent over usage on the internal SD

This means external SD would need to be powered up at all times -> battery drain (it is present with APPS2SD - or whatever this name was)

Wuld this mean that we would have extra ram available for running apps...like SGS task manager will show more than 311Mb RAM ?
If this is the case then I am very interestied, since I don't care about speed so much. I just need to run an app that currently can not run due to out-off-memmory (needs 130Mb of RAM) for pure presentation purposes

There is a app in market called swapper2 which can make use of the swap partition or creates a swap file for use. I had been using this app since my HTC MAGIC and now on SGS.
I'm currently using swap partition that had been created earlier in my class 6 SDCard. Works on both eclair or froyo kernels on SGS. So far I am not complaining, with swappiness 20, there is not much of memory hog or lag due to opening too many apps or single memory hogging apps (like flash on browser) on my XXJPK, the swap memory gets allocated and deallocated as you can tell from the swapper info feature.
But the battery effects is something to think about though, sdcards are cheap so I don't mind sacrificing it. The other way is to create a swap file on the rfs and use it if you value your sdcard. The screenshot provided is a normal usage of my device with a few apps running at background (Still gonna be 300+ RAM, nothing magical about it though) and I had also used minfree tweak on the kernel.
You can try and see if it helps in terms of performance for a few days. I cant vouch for the swapper a lot as I'm using it myself - I am more uncomfortable without it though. What Xan said does makes sense but there are rare times when the things that doesn't makes sense gives us surprises.
A good read up and comments from people who had tried and used it in different scenarios...
http://zerocredibility.wordpress.com/2009/08/24/why-android-swap-doesnt-make-sense/
Sent from my GT-I9000 using Tapatalk

[Q] Apps2sd Pros and Cons

Total noob question, but I'm gonna ask anyways. What are the pros and cons of storing apps on your sd card instead of the internal memory. I'm debating on whether or not I should use this feature. I know that it frees up internal memory, but at what cost? Does it free up any ram? Does it increase or decrease your phones performance? And bottom line....is it worth it? And do you use it? Thanks for the input

It's not exactly what you'd call a "newbie" question but at the same time by no means something you couldn't have google'd and found about, thus eliminating the need for this thread.
Apps2SD allows you to install android applications to the SD Card. For a phone like the Desire Z, which has a lot of internal storage (1GB dedicated to applications) it really has no use for this. I guess this was made fore phones that didn't have a lot of internal storage (like the HTC Desire for example). The downside to this is that SD apps will have slower loading times. (since SD Cards are slower than eMMC chips)
It's a great feature, but for our device it is useless as we have enough internal storage space for applications.

Slow SD cards could slow down your apps, and connecting and disconnecting micro SD card from computer can also cause issues with apps on the SD card.

Okay. Based on that info I'm going to opt out of using that feature then. And in the future I will be sure to use google before creating a thread. Thanks for the input!

Apps to SD card

Since source came out allowing kernel tweaks I've noticed some excitement over being able to move apps to SD card. I've never messed with this before but at the moment I'm in the process of moving my apps to my external SD card.
I've got a 32gb external storage and have about 20gb's left on it. My internal storage is low tho with about 2gb's left. A question I have is I believe I remember reading somewhere about some apps not running well off external SD.Is that a concern? Besides being able to move storage around......are there any other noticable pro's and con's that come with this.
By the way I'm running Dazed latest 1.5 with agats latest kernel running SmartassV2 overclocked to 1.3 using Tegrak. Where I work I have a terrible data signal/speed. After flashing the source kernel from Agat with a few tweaks I'm able to actually open apps I wasn't able to previously.
Awesome stuff.
[EDIT] Also, I always use Titanium Backup to restore my apps. Having apps on SD card..... does this effect in anyway I use TB afterwards.
Thanks
Never mind.... blackcanopy just answerd this in agats thread.
Mods you can close this.

I know that different SD cards have different read/write speeds.
A lower class is intended for lesser resource draining tasks; viewing single low Q photos, maybe listening to an mp3, or simply used as slow portable storage.
A higher class allows smooth hq photo viewing, video loading.
And the highest classes, class 10 and UHS(ultra high speed) are where you can store and view large raw photo files, and load 1080p video flawlessly.
(The latter, uhs, simply does it much faster, reportedly up to 40mbps transfer. However I am unsure if UHS is supported by the E4GT)
Now with all this, I'm not sure where reading applications may lie...
To speculate:
Applications (in my understanding) vary greatly with read/write speeds, between one another and within themselves.
At boot the app may have no issues, but as it progresses it may act upon higher speed requests, and if your SD class is on the lower end, it may not run smoothly.
I'm unsure where apps compare to SD cards, but I would assume that some of my apps would require high r/w speeds.
This is mostly speculative because I am unsure what the internal SD read/write speeds are, and how they compare.
My point could be moot.
Anyway just thought I'd share what I've learned on SD cards this past week, sorry op if it's no help!
FF18 SFHub Rooted

[Q] Use Internal Storage as Virtual Memory on CM9?

Now that we can swap the space used by Internal Storage over to our External SD card, would it be possible to use the Internal Storage as some sort of extension to RAM?
We got 1.7GB of storage that's not doing much of anything. If all of it or even most of it could somehow be added on to useable memory, we could have more programs open at any one time and still not lag.
If this can be done, what's the best (safest/easiest) way to do it?

cooltrix said:
Now that we can swap the space used by Internal Storage over to our External SD card, would it be possible to use the Internal Storage as some sort of extension to RAM?
We got 1.7GB of storage that's not doing much of anything. If all of it or even most of it could somehow be added on to useable memory, we could have more programs open at any one time and still not lag.
If this can be done, what's the best (safest/easiest) way to do it?
Click to expand...
Click to collapse
Make it into swapfile, you mean?
If the kernel support swapfiles, yes it can be done ...
... BUT ...
... you will shorten the life of the Internal Storage, and possibly, significantly.
And when the Internal Storage dies... you can't replace it.
And, yes, it will die, sooner or later... it's not a question of "if" but a question of "when"... and I'm sure it will die much sooner if you put a swapfile in it...

pepoluan said:
Make it into swapfile, you mean?
If the kernel support swapfiles, yes it can be done ...
... BUT ...
... you will shorten the life of the Internal Storage, and possibly, significantly.
And when the Internal Storage dies... you can't replace it.
And, yes, it will die, sooner or later... it's not a question of "if" but a question of "when"... and I'm sure it will die much sooner if you put a swapfile in it...
Click to expand...
Click to collapse
How many read/write operations before it burns out, you reckon? Would it be more or less than a physical drive?
Coz if this was possible, it would be very nice to have 2GB mem. LOL

cooltrix said:
How many read/write operations before it burns out, you reckon? Would it be more or less than a physical drive?
Coz if this was possible, it would be very nice to have 2GB mem. LOL
Click to expand...
Click to collapse
A spinning-disk drive has no limit to its rewritability.
A very-high-quality flash memory cell can last 1'000'000 write cycles. But I don't believe that our Galaxy W use that kind of flash memory. So, a more common number is 100'000 write cycles. When you're talking about swapfile, you're talking about at least 100 swaps per day, and possibly more. If you do not tune other parameters so that Android will not use the flash unless it absolutely have to, you can easily go over 1'000 writes per day.
When the counter passes 100'000... well, I'll say prepare to buy a new phone because the internal storage is not replaceable...
_____ Galaxy W + Mutant ROM + xda app _____

pepoluan said:
A spinning-disk drive has no limit to its rewritability.
A very-high-quality flash memory cell can last 1'000'000 write cycles. But I don't believe that our Galaxy W use that kind of flash memory. So, a more common number is 100'000 write cycles. When you're talking about swapfile, you're talking about at least 100 swaps per day, and possibly more. If you do not tune other parameters so that Android will not use the flash unless it absolutely have to, you can easily go over 1'000 writes per day.
When the counter passes 100'000... well, I'll say prepare to buy a new phone because the internal storage is not replaceable...
_____ Galaxy W + Mutant ROM + xda app _____
Click to expand...
Click to collapse
So better to map that to External then, if at all possible?
Any ideas on how the system could use Internal storage to improve our Wonders?