Develop Bugs

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.
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android53 said:
What are the possibilities of using our 2gb of ddr program storage and re allocating it as system ram?
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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!
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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
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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
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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.
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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
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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/
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[Q] Dalvik cache to sd-ext

would this free up space I am using VR Kingdom and is it advisable

Yes, it can, however, if your device is performing sufficiently as-is, I wouldn't move the dalvik. Do a little bit more research. I haven't heard of anyone claiming huge performance increases by moving the dalvik to SD.

dougjamal said:
Yes, it can, however, if your device is performing sufficiently as-is, I wouldn't move the dalvik. Do a little bit more research. I haven't heard of anyone claiming huge performance increases by moving the dalvik to SD.
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Thanks will do

Only IF
I am trying to move my dalvik or upsize the folder (which is limited to 160MB on mu EVO 4G) because once the dalvik threshold has been acheived you will receive the dreaded "There is insufficient room on the device" error message when trying to install applications

dougjamal said:
Yes, it can, however, if your device is performing sufficiently as-is, I wouldn't move the dalvik. Do a little bit more research. I haven't heard of anyone claiming huge performance increases by moving the dalvik to SD.
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Click to collapse
You don't move dalvik to the SD card for performance increases. If anything, it slows it down (particularly on boot). The only reason to move it is for extra space.

Mine has shown zero performance loss on MIUI and better performance when I was on Blazing Roms Fusion. MUCH better performance. Moving Dalvik on Fusion freed up 200MB of internal space, which would ONLY result in better performance.
It's like Windows after a temp/cache file cleanup and defrag.

Can anyone chime in on wether my used/free memory amounts look normal? I have 181 apps in total and a2sd running, an 8gb card. I do have navigon installed which the maps suck up 1.5gb of my SD card. I am not having any issues, just want to make sure I didn't screw anything up.. Thanks for any input/advice.
ROM
367MB (total)
147 MB (free)
Internal
446 MB (total)
309 MB (free)
SD
7 GB (total)
3.9 GB (free)
SD(a2sd)
959 MB (total)
672 MB (free)
**Edit**
Disregard, looks like I'm in good shape. Thanks.

[Q] something better than link2sd for stock rom?

I'm using the stock kernel and, of course, facing issues with the small internal memory. I'm using link2sd, but it still leaves a fair amount of data in the internal memory (ie, 16 mb for Asphalt 6, 14 mb for Facebook, 13 mb for Flash, a couple of mb for many other apps), so I'm always with a somewhat limited space for applications.
So I wonder if there is something capable of moving far more data to the SD card, so I don't need to worry about having enough room for apps. I was looking at https://play.google.com/store/apps/details?id=com.spazedog.mounts2sd but it mentions init.d support, and googling about all that stuff doesn't really explain it in more layman terms.
Thanks in advance

You cant be using Link2Sd properly then. It leaves virtually nothing in the internal memory. I had a 32gb SD card full of games and still had about 200mb free internal memory. When you create a link are you trying to move the apps to SD afterwards as they should show as being on internal?

Well, I have it set up to link automatically on application install, and to link application, dalvik-cache and libraries. The install locationis set to external and I have ticked the check boxes to relink libraries and dex files at startup.
To test it, I've unistalled Facebook and reinstalled. Once the app finishes installing, I get the link2sd notification that it's linking it to the SD. I login to my account and once I go to the application settings to check the app size, it reports a total of 31,33 MB, of which 23,56 MB correspond to the aplication and 7,77 MB to data. And has the option to move to the SD so it's certainly in the internal memory.
Link2SD storage info reports the internal memory (380 Mb total, 15% free), the Sd card (12% free) and the sd card's second partition, at /data/sdext2, with 712 MB total, of which 390Mb are used.

Sorry for bumping, but is the link2sd behaviour I'm describing normal behaviour then?

juanml82 said:
Sorry for bumping, but is the link2sd behaviour I'm describing normal behaviour then?
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Yes, it does appear to be normal behaviour. Try going into the Link2SD app and see if it says whether the app is linked or not. I've had instances where my apps don't get linked even after running the process. When you check the application size in settings (not in Link2SD), the application size will remain unchanged as I think Link2SD treats your partition as internal storage and therefore it still shows the application as it's full size as opposed to how much of it is actually on your internal storage
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It's nice to be important, but it's more important to be nice.

Heapsiza and Jit question

I'm running the Pacman ROM and it runs pretty good, but I want to maximize performance. I have some questions that I hope one of you will answer.
1. Is the Heapsize set with the ROM that gets flashed, or is it internal? What number is it set at, and what number do I want it at?
2. I am S-OFF and I'd like to know more about activating the a2sd Jit. Unfortunately there isn't much info for the Evo on this. What is DalvikDM Jit and what does it do?
3. I'm looking at the Low Memory Killer Commands on the a2sd help, but I'm not sure if I need to adjust anything here because I've done this with Android Tuner and if screws everything up. I'm probably doing it wrong. Can you tell me about this and where I might like to set it at with a2sd.
Thanks for reading my post.

Sleepycloud said:
I'm running the Pacman ROM and it runs pretty good, but I want to maximize performance. I have some questions that I hope one of you will answer.
1. Is the Heapsize set with the ROM that gets flashed, or is it internal? What number is it set at, and what number do I want it at?
2. I am S-OFF and I'd like to know more about activating the a2sd Jit. Unfortunately there isn't much info for the Evo on this. What is DalvikDM Jit and what does it do?
3. I'm looking at the Low Memory Killer Commands on the a2sd help, but I'm not sure if I need to adjust anything here because I've done this with Android Tuner and if screws everything up. I'm probably doing it wrong. Can you tell me about this and where I might like to set it at with a2sd.
Thanks for reading my post.
Click to expand...
Click to collapse
1. Is the Heapsize set with the ROM that gets flashed, or is it internal? What number is it set at, and what number do I want it at?
At runtime, the heap grows dynamically in size as the Dalvik VM requests system memory from the operating system. The Dalvik VM typically starts by allocating a relatively small heap. Then after each GC run it checks to see how much free heap memory there is. If the ratio of free heap to total heap is too small, the Dalvik VM will then add more memory to the heap (up to the maximum configured heap size).
That being said, the reason why you are not seeing "24 mb" on your DDMS screen is because the heap hasn't grown to its maximum size. This allows Android to make good use of the already small amount of memory that is available on handheld devices.
As for why your application is crashing on the emulator and not your phone, that does seem odd (are you sure the numbers are correct?). You should keep in mind, however, that memory is managed dynamically and that total memory utilization is determined based on a number of external factors (the speed/frequency at which garbage collection is performed, etc.).
Finally, for the reasons I mentioned above, it would be difficult to say for sure how well your application manages memory based on the single line of information you provided above. We'd really need to see some of your code. OutOfMemoryErrors are definitely worth worrying about, however, so I'd definitely look into your application's memory usage. One thing you might consider is to sample your bitmap images at runtime with calls to inSampleSize using the BitmapFactory class. This can help reduce the amount of memory required to load your drawable bitmaps. Either that or you could reduce the resolution of your drawables (although 20 kb each sounds fine to me).
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Click to collapse
2. I am S-OFF and I'd like to know more about activating the a2sd Jit. Unfortunately there isn't much info for the Evo on this. What is DalvikDM Jit and what does it do?http://android-developers.blogspot.com/2010/05/dalvik-jit.html

Diablo67 said:
1. Is the Heapsize set with the ROM that gets flashed, or is it internal? What number is it set at, and what number do I want it at?
2. I am S-OFF and I'd like to know more about activating the a2sd Jit. Unfortunately there isn't much info for the Evo on this. What is DalvikDM Jit and what does it do?http://android-developers.blogspot.com/2010/05/dalvik-jit.html
Click to expand...
Click to collapse
Now I understand why it's sometimes said to "let the ROM settle in for 15 minutes before you dig in," and "It gets faster after a day." Some previous versions of Jit "warm up to speed", but Dalvik Jit is almost instantaneous in response to a given command.

[Q] SD Card Partition SM-T800

Hey,
So, I've looked around and only found non-product specific related threads about sdcard partioning.
I would like know if it's worth doing a swap partition and anything else on the stock rom of the sm-T800.
Advice please.

ivyhole said:
Hey,
So, I've looked around and only found non-product specific related threads about sdcard partioning.
I would like know if it's worth doing a swap partition and anything else on the stock rom of the sm-T800.
Advice please.
Click to expand...
Click to collapse
Forget about creating a swap partition on your sd card. This device has 3gb of fast ram and has no need of a swap partition on the sd card. It's more likely to hinder and slow the device than benefit.
Not only that root will be needed.

ashyx said:
Forget about creating a swap partition on your sd card. This device has 3gb of fast ram and has no need of a swap partition on the sd card. It's more likely to hinder and slow the device than benefit.
Not only that root will be needed.
Click to expand...
Click to collapse
Cannot agree with this statement "This device has 3gb of fast ram and has no need of a swap partition on the sd card. "
The following statement maybe true " It's more likely to hinder and slow the device than benefit." But we need to test this first before we make claims.
Both statements are unsubstantiated without any metrics to support them. It's like saying "your computer has 3gb of fast RAM and has no need of ...." - how do we judge what "fast RAM" is, how much does "3gb" get you, what applications you run most often and how they perform, how much killing and kicking the OS does because it keeps running low on memory and follows an aggressive scheduler, and so on.
My personal experience is that both the OS and applications are written to expect very low levels of RAM and both the OS and the applications unload their data as soon as they can, resulting in unnecessary "reloading" over the internet, which further implies increased internet data usage, which, in some countries, eg Europe, we still pay for, dearly.
It is not funny at all when I travel abroad and take my tablet with me, enable Roaming only for a second to say check emails and view a few web pages (like booking.com trying to view / book a hotel room), and then switching Roaming off, however when I go back to read those pages 50% of the time they are gone! It seems that anything more than 3-4 tabs on the browser and they will go. Or maybe I should not have opened that speadsheet or whatever it was that I did and I cannot remember, maybe I looked at it the wrong way.
So let's find a way to improve this - we cannot increase the onboard RAM, but maybe since SD Cards are replaceable and cheap, we could give it a bit more RAM to play with, not sure how well that would work. There is a relevant thread hereabouts with instructions of how to do just that (if I could find it)