Database Info

getting swapfile working on /data partition

Im trying out a theory. I running JAC Hero 2.3 and wanna try running the swapfile on the /data partition. I moved app_s over to /system/sd and used swapper app to create the swapfile but android doesnt seem to use it. when i run free It says Total/used/free are all 0 but the swap file is 34 meg. I tried putting it in a sub folder and chown root.root on the folder before setting up and still no luck. Anyone have any ideas why it wont work on /data or how to get it to work on /data?

Once you run swapper go into the setting and change the location of your swap file from /sdcard/swapfile.swp to /system/sd/swap.swp ( see sxfx post[url]

you don't want to do that. Swapping involves a lot of writing and erasing, it'll wear out your internal chip and you'll start experiencing reduced capacity, write cycles for nand are even less than for flash memory!

jubeh said:
you don't want to do that. Swapping involves a lot of writing and erasing, it'll wear out your internal chip and you'll start experiencing reduced capacity, write cycles for nand are even less than for flash memory!
Click to expand...
Click to collapse
not to mention, swapon as implemented (on every build i've tried) doesn't work on a swapfile stored on a yaffs2 partition

jubeh said:
you don't want to do that. Swapping involves a lot of writing and erasing, it'll wear out your internal chip and you'll start experiencing reduced capacity, write cycles for nand are even less than for flash memory!
Click to expand...
Click to collapse
Actually /sdcard/ is your fat32 portion of your sd card, /system/sd/ is the ext2/3 of your sd card.
Also I have done a bunch of research on this write/read fiasco just because of android.
And even if you set a swap file to your SD sure it will shorten your life of the card but it will still last you at least 2 years.
I have been using USB devices on linux as swap locations forever now and I still have thumb drives that have been used and abused for months and months as a swap place and they are still pulling strong.
As for the internal chip, Im not sure what you mean by that?

Even if you could put swap on the internal flash, its not going to be faster.
Putting swap on the internal flash will make things slower as the internal flash is about 3 to 5 times slower than a class 6 sdcard.

you're comparing using a flash drive for swap in a full blown computer that probably has around 1-4gb of ram, the swap file is hardly ever touched, unless you're running a lot of applications at a time. Dream has only 90 mb available to dalvik, and rosie is a big fat... lady... plus linux/dalvik manage memory in a different way, so files are often dropped to swap and they dont stay there for long (maybe in a 256 swap, but not in a 32 mb one).
the OP also is talking about moving his swap to his internal storage (chip, nand, whatever), as he thinks it's having no effect working from the sd card. Personally, i think that both a2sd and swapper are flawed. They're overcompensating for an os that was not meant to run on that device, and the real work should be in porting (as in developing, not just file-swapping as most "devs" do here) a launcher app that we can feel comfortable with running on a stock android system with stock (or slightly improved) libraries and that we can call comparable to rosie. Just look at ahome or dxtop or openhome, they're good, solid, great looking home replacements that work as well or better than rosie, but they run out of the stock libraries. I wonder why nobody has made a free, open source home replacement app yet

jubeh said:
you're comparing using a flash drive for swap in a full blown computer that probably has around 1-4gb of ram, the swap file is hardly ever touched, unless you're running a lot of applications at a time. Dream has only 90 mb available to dalvik, and rosie is a big fat... lady... plus linux/dalvik manage memory in a different way, so files are often dropped to swap and they dont stay there for long (maybe in a 256 swap, but not in a 32 mb one).
the OP also is talking about moving his swap to his internal storage (chip, nand, whatever), as he thinks it's having no effect working from the sd card. Personally, i think that both a2sd and swapper are flawed. They're overcompensating for an os that was not meant to run on that device, and the real work should be in porting (as in developing, not just file-swapping as most "devs" do here) a launcher app that we can feel comfortable with running on a stock android system with stock (or slightly improved) libraries and that we can call comparable to rosie. Just look at ahome or dxtop or openhome, they're good, solid, great looking home replacements that work as well or better than rosie, but they run out of the stock libraries. I wonder why nobody has made a free, open source home replacement app yet
Click to expand...
Click to collapse
You make a very good point about computer having 1-4gigs of ram and not needing a swap file.
Honestly I almost never run a swap file on a computer that has more then 1gig of ram.
Plus90% of the time when I do run a swap file is when Im running a live distro of linux of a cd, but also 90% of the time I run the distro from the flash drive instead of cd cause its much faster.
So now imagine how many reads/writes I abuse that flash drive with by running a full OS on it.
Also I don't understand how a2sd or swapper is flawed? Just because they do their job? I mean it's not really our fault that they made the G1 with a little less memory spaces then we would like it to have.
But that's exactly why we have tools like swapper and a2sd. Plus no one is really forced to run these roms on the G1 phone and those of us that do realize that we have to take extra steps in creating tools to help it.
And that's not only true for the G1 but anywhere in the computer world these days.

dwang said:
Even if you could put swap on the internal flash, its not going to be faster.
Putting swap on the internal flash will make things slower as the internal flash is about 3 to 5 times slower than a class 6 sdcard.
Click to expand...
Click to collapse
I'd like to spread swap over the sd and internal storage if possible -- should make paging a lot less evident if priorities are set up properly.

dwang said:
Even if you could put swap on the internal flash, its not going to be faster.
Putting swap on the internal flash will make things slower as the internal flash is about 3 to 5 times slower than a class 6 sdcard.
Click to expand...
Click to collapse
internal memory is faster. class 6 guarantees 6mbs read/write times but doesnt mean the bus can support those times. if you run a test copying something to /system/sd and to /data you will see /data is faster. as for those saying it will degrade the internal memory, that is not the case being the flash memory inside is designed to have much much much more read/write cycles. Think about it in a stock G1, this is where dalvik-cache is writen to as well as email, sms, user settings, cache for browser and uTube. Do not confuse internal flash memory to sd card flash memory

Are you sure about that? This guy has some test results and it indicates that a class 6 sdcard is much faster than the internal flash.
http://forum.xda-developers.com/showpost.php?p=4059520&postcount=15
MonkySlap said:
internal memory is faster. class 6 guarantees 6mbs read/write times but doesnt mean the bus can support those times. if you run a test copying something to /system/sd and to /data you will see /data is faster. as for those saying it will degrade the internal memory, that is not the case being the flash memory inside is designed to have much much much more read/write cycles. Think about it in a stock G1, this is where dalvik-cache is writen to as well as email, sms, user settings, cache for browser and uTube. Do not confuse internal flash memory to sd card flash memory
Click to expand...
Click to collapse

dwang said:
Are you sure about that? This guy has some test results and it indicates that a class 6 sdcard is much faster than the internal flash.
http://forum.xda-developers.com/showpost.php?p=4059520&postcount=15
Click to expand...
Click to collapse
That's interesting. Going to have to try that test out. I just noticed when xfering stuff to /data it was faster then to /system/sd. If it is then touche my friend.....touche

[g1] Partitioning The Ram?

I understand that this probably will get moved and placed elsewhere under some long post but I'd like to make an individual thread and catch the eyes of people who wouldn't go through those threads to find this.
Any who can we partition the Ram like we did the sd card for apps?
Why?
To set and limit core apps and fix force closings [possibly] and making space for third party apps to run smoothly.
I don't know if it is possible but I do think it is a beautiful idea.

No, there's no way to accomplish anything like that(at least nothing I've ever heard of and I'm a software engineer)

I'm glad that you feel your idea is more important than everyone elses.
No, you can't partition RAM.

i don't know about android OS but ram drives can be created in linux
ram drive is important for ssd users and is created with tmpfs in fstab

There already are memory usage limits set for different types of applications. You can see this in init.rc. But it's not practical to "partition" the memory or limit the memory used by backgroud apps. As you can see the default policy is actually biased towards background services, etc.

samygent said:
i don't know about android OS but ram drives can be created in linux
ram drive is important for ssd users and is created with tmpfs in fstab
Click to expand...
Click to collapse
Yes, they can be created in Android. That is what compcache uses. But from what I read in the OP, that isn't what he is looking for. Maybe I misunderstood him but it sounded like he wanted to limit certain applications from being able to use too much memory. A RAM drive is available to the OS to manage, right? I don't know of any way to stop a specific application from using a RAM drive.

could he be talking about like how the spl partitions data cache and system?

you mount the ram drive like a normal disk and copy whatever files you want on that partition but sadly everything is lost when you reboot
i would like to try it but i don't want to brick my phone by messing up with my fstab

I think i understand he's question. Would it be possible to use g1 internal memory only for hungry tasks and swap partition for the rest ?
I wish it was but sadly it not possible. I hate it too when some silly task take internal memory space with is way faster then sd swap speed
and now that i think about it , ram drive would'nt really help simply because android applications take very low space on drive

samygent said:
you mount the ram drive like a normal disk and copy whatever files you want on that partition but sadly everything is lost when you reboot
i would like to try it but i don't want to brick my phone by messing up with my fstab
Click to expand...
Click to collapse
I was trying to do it based on some stuff I googled. I can't get it to work. It may not have support for it by default. It could be that Compcache loads what it needs to so that it can create a Ramdisk.
Post the steps that you would use and I will try it. It won't brick my phone, I'll just have to wipe and reload which is no big deal.

not gonna mess with fstab for the moment but you can try this
create a dir somewhere, mkdir -p /system/ram
and then
mount -t tmpfs -o size=5M,mode=0744 tmpfs /system/ram
you now have a 5mb ram drive
copy something on it to test

samygent said:
not gonna mess with fstab for the moment but you can try this
create a dir somewhere, mkdir -p /system/ram
and then
mount -t tmpfs -o size=5M,mode=0744 tmpfs /system/ram
you now have a 5mb ram drive
copy something on it to test
Click to expand...
Click to collapse
It might have to wait until I get off Hero but I will try it.

i'm using hero
funny thing is , i created a 100 mb ram drive, copy something on it and umount it. swap is almost full and 35mb free on internal ram
then tried to start hero browser and it started in about less then 2 secs

samygent said:
i'm using hero
funny thing is , i created a 100 mb ram drive, copy something on it and umount it. swap is almost full and 35mb free on internal ram
then tried to start hero browser and it started in about less then 2 secs
Click to expand...
Click to collapse
Interesting. Try setting it as a swap device. Are you sure it created it from RAM? Is there really 100Mb of RAM free?

yup my hero is a lot faster now
create ram partition, copy big ass file ( 80 mb hero file ) phone is very slow
ram and swap are used up to 100%
umount the ram partition , 50 mb free on internal ram and 50 mb used on swap partition
internal ram goes down to 1-2 mb free space after a few seconds but phone is very damn fast and swap is still filled up to 50 mb

samygent said:
yup my hero is a lot faster now
create ram partition, copy big ass file ( 80 mb hero file ) phone is very slow
ram and swap are used up to 100%
umount the ram partition , 50 mb free on internal ram and 50 mb used on swap partition
internal ram goes down to 1-2 mb free space after a few seconds but phone is very damn fast and swap is still filled up to 50 mb
Click to expand...
Click to collapse
You are basically just forcing the phone to use all swap instead of RAM. Some people set their swapiness to 100, which makes the phone use swap whenver possible. It's strange that swap would perform better than internal RAM. I have some ideas for making Hero run better but I can't get Compcache running on JACxHEROski. Which Hero are you running?

miketaylor00 said:
You are basically just forcing the phone to use all swap instead of RAM. Some people set their swapiness to 100, which makes the phone use swap whenver possible. It's strange that swap would perform better than internal RAM. I have some ideas for making Hero run better but I can't get Compcache running on JACxHEROski. Which Hero are you running?
Click to expand...
Click to collapse
You need to do it via rzstool

And her I thought I was an idiot for not being able to get get compcache running thru the userinit....

I'm sorry to hear that this seams like it can't be done currently but I'm glad I at least created some good conversation amongst everyone.
My whole idea for this was to partition the core apps and limit them/section them to only a certain amount of space to avoid them from force closing since they could have an appropriate amount of dedicated ram to keep them going clean and strong then after all that was taken care of third party apps could have a little space left to run a lot better.
I guess I'm more so just thinking about sectioning off the ram to apps then third party apps.

First off, don't get compcache running through userint.sh edit the user.conf file.

not clear to me from search what is current state of swap && / || CCache

Can anyone direct me to a guide somewhere?
I'd like to make an ext partition? Or would I? Is Swapper 2 just as fast? Tradoffs? Anyone run into their sd card wearing out yet?

bueler?
The message you have entered is too short. Please lengthen your message to at least 10 characters.

The consensus seem to be "do not use" except as 'last resort', and only needed on phones with 256MB or less of mem.
I wrote this, and I am waiting for a technical review from some experts in this field.
http://forum.xda-developers.com/showthread.php?t=897823

kschang said:
The consensus seem to be "do not use" except as 'last resort', and only needed on phones with 256MB or less of mem.
I wrote this, and I am waiting for a technical review from some experts in this field.
http://forum.xda-developers.com/showthread.php?t=897823
Click to expand...
Click to collapse
I have 256MB ram
At the moment, Compcache is good enough, but I can't help but wonder how much better it could be with swap instead of Compcache.
edit: "For example, If you have a 256MB system (shows as 262MB due to 1024 vs. 1000 KB size difference) and have 130MB of apps and data/cache loaded, then that leaves about 130MB for the system to actually RUN programs. That sounds like a lot, but in reality that is not enough, since the system itself takes 50-80MB, and services will take up another 30-50MB, leaving almost nothing. "
quick review, you don't appear to be differentiating between RAM and Flash? Having more apps installed shouldn't increase RAM usage at all. Unless I gravely misunderstand the Android OS, if I install a new program, it resides in the system flash, not the RAM, until I run it, at which point it gets loaded to RAM. When the system needs memory and no swap or Compcache is in use, it writes the state of the application to the flash and removes it from RAM.
What the swap does is similar to what compcache does-- compresses apps that are currently in RAM, and moves them to the swap space. In the case of Compcache, this is in the RAM. But since you're compressing it, background apps don't take nearly as much RAM, and you get an app switching speedboost because the processor can uncompress the compcache'd program, "move" it to RAM, compress the currently running program in RAM, and "move" it to the compcache. Forgive me if you already said this, I can't read the entire thing at the moment.
As for swap, I'm not sure if the processor compresses before going to the hard swap file, I don't think that it does-- when android starts getting low on RAM, it moves what was in RAM, to the swap on the SD-card. Since it does this when the system is low on RAM, and not when the system runs out of RAM, you never notice it. Reading the app back from the SD card happens almost instantaneously, because the sd cards can be read from at a speed of at least 20MB/s, maybe more. When you're restoring an app to RAM, 20MB/s is plenty.
edit2: I'm sorry but this guide is too vague to be anything more than moderately informative. Comments like:
-"CompCache, or "compressed cache", is handled by the Linux kernel. It takes a portion of your memory, and use it as a cache space, but compressed. By using on-the-fly compression it is able to make your memory appear to be a bit larger than it actually is. However, the result is slower performance.
This is usually NOT tweakble without mod ROM such as Cyanogen Mod. The kernel also must support this feature, and not all do. This also slows your phone. "
-"...swap space by either creating a swap file or a swap partition. This adds a lot of read/write action to your SD card and may substantially decrease its usable life."
-"This really slows your phone."
People wouldn't be doing these things for no reason. Compcache does not "make your memory appear a bit larger", when it at least doubles the amount of usable RAM-- when you allocate 60MB, if you average 75% compression (I usually see between 65% and 80%), do you know how much RAM this effectively nets you? Over at least 60MB extra, usually about 80! So my phone goes from having 256MB ram to having 340 effectively. Having your processor overclocked minimizes any slowdown from the compression/decompression; I haven't noticed any slowdown, and having the "extra" RAM definitely has made my phone more able to multitask.
You basically discourage users from doing ANYTHING like swapping, compcaching, etc to their phone, saying it "slows it down" and "can substantially decrease your SD Card's life". My experience has been otherwise regarding slowing it down, and regarding the SD card, the only part that would actually go bad is the swap partition. If you put that at the end of the drive, when it goes bad, you'll know, and you can just move the partition back 300MB and put your 300MB swap there. We haven't heard of any users' cards going bad from this yet. Also, if you have a class 6+ SD Card, they implement wear leveling on the card, so you don't need to worry about wearing out any individual bits.
Sorry, I'm just not digging it.

rancur3p1c said:
I have 256MB ram
Click to expand...
Click to collapse
Me too, me too...
At the moment, Compcache is good enough, but I can't help but wonder how much better it could be with swap instead of Compcache.
Click to expand...
Click to collapse
So try it. With CM612, I have CompCache AND Swap (through Swapper2 / 128 MB) turned on. It slows down every once in a while but my programs don't crash any more.
edit: "For example, If you have a 256MB system (shows as 262MB due to 1024 vs. 1000 KB size difference) and have 130MB of apps and data/cache loaded, then that leaves about 130MB for the system to actually RUN programs. That sounds like a lot, but in reality that is not enough, since the system itself takes 50-80MB, and services will take up another 30-50MB, leaving almost nothing. "
quick review, you don't appear to be differentiating between RAM and Flash? Having more apps installed shouldn't increase RAM usage at all. Unless I gravely misunderstand the Android OS, if I install a new program, it resides in the system flash, not the RAM, until I run it, at which point it gets loaded to RAM. When the system needs memory and no swap or Compcache is in use, it writes the state of the application to the flash and removes it from RAM.
Click to expand...
Click to collapse
At first I thought the same way you did, until I started looking in "diskusage".
According to diskusage, there is no separate RAM. 256MB is 256MB. App storage is where everything goes, and what's left is used to load services and such. The numbers I added up matches. I have 256 MB phone. 100 is for apps, which leaves about 150-160. System itself takes 50-80 (acore, gapps, phone, system...) then add a few services and you're down to 30-40 MB free to actually run the programs. The numbers seem to match up to what's shown at the bottom of "Manage Services".
I know it's weird, but perusal of Android developers kit doesn't contradict this understanding.
What the swap does is similar to what compcache does-- compresses apps that are currently in RAM, and moves them to the swap space. In the case of Compcache, this is in the RAM. But since you're compressing it, background apps don't take nearly as much RAM, and you get an app switching speedboost because the processor can uncompress the compcache'd program, "move" it to RAM, compress the currently running program in RAM, and "move" it to the compcache. Forgive me if you already said this, I can't read the entire thing at the moment.
As for swap, I'm not sure if the processor compresses before going to the hard swap file, I don't think that it does-- when android starts getting low on RAM, it moves what was in RAM, to the swap on the SD-card. Since it does this when the system is low on RAM, and not when the system runs out of RAM, you never notice it. Reading the app back from the SD card happens almost instantaneously, because the sd cards can be read from at a speed of at least 20MB/s, maybe more. When you're restoring an app to RAM, 20MB/s is plenty.
edit2: I'm sorry but this guide is too vague to be anything more than moderately informative. Comments like:
-"CompCache, or "compressed cache", is handled by the Linux kernel. It takes a portion of your memory, and use it as a cache space, but compressed. By using on-the-fly compression it is able to make your memory appear to be a bit larger than it actually is. However, the result is slower performance.
This is usually NOT tweakble without mod ROM such as Cyanogen Mod. The kernel also must support this feature, and not all do. This also slows your phone. "
-"...swap space by either creating a swap file or a swap partition. This adds a lot of read/write action to your SD card and may substantially decrease its usable life."
-"This really slows your phone."
People wouldn't be doing these things for no reason. Compcache does not "make your memory appear a bit larger", when it at least doubles the amount of usable RAM-- when you allocate 60MB, if you average 75% compression (I usually see between 65% and 80%), do you know how much RAM this effectively nets you? Over at least 60MB extra, usually about 80! So my phone goes from having 256MB ram to having 340 effectively. Having your processor overclocked minimizes any slowdown from the compression/decompression; I haven't noticed any slowdown, and having the "extra" RAM definitely has made my phone more able to multitask.
Click to expand...
Click to collapse
It also seriously depends on your SD card. I've read reports on Phandroid that said class 6 or 8 microSD cards would provide almost lag-free swaps, but that's on a G1 (which is already a slow phone).
You basically discourage users from doing ANYTHING like swapping, compcaching, etc to their phone, saying it "slows it down" and "can substantially decrease your SD Card's life". My experience has been otherwise regarding slowing it down, and regarding the SD card, the only part that would actually go bad is the swap partition. If you put that at the end of the drive, when it goes bad, you'll know, and you can just move the partition back 300MB and put your 300MB swap there. We haven't heard of any users' cards going bad from this yet. Also, if you have a class 6+ SD Card, they implement wear leveling on the card, so you don't need to worry about wearing out any individual bits.
Sorry, I'm just not digging it.
Click to expand...
Click to collapse
Constantly reading and writing the file will cause that area to get much heavier use and eventually cause it to fail the bootup "checking SD card". The only question is how much life is taken away.
I am running my Droid on 24% CompCache AND 128MB Swap right now. Occasional lag but otherwise runs quite well. It's also overclocked to 1.2 GHz with P3Droid's kernel. So I do practice somewhat of what I preach...

so if I have 512MB of ROM, and 256MB of RAM, and I fill up my ROM with programs, how much RAM do I have?
I don't follow how what you said can be.
SD Card writes-- SanDisk guarantees theirs for 100K writes to any given sector...that's good enough for the swap to not be a problem in the near future IMHO.

let's put it this way...
Here's the specs of Moto Droid from Motorola itself (http://developer.motorola.com/products/droid/)
RAM 256 MB
FLASH ROM 512 MB
USER STORAGE AVAILABLE (MAX) 256 MB
So the REST of the ROM clearly is to hold the Android OS itself. The actual programs you can load for running? 256MB. That's app storage.
I've always wondered if there's a way to read the actual ROM contents and enumerate that... But that's for another topic.

Found this useful post: boot process of Android OS
http://www.androidenea.com/2009/06/android-boot-process-from-power-on.html
Furthermore, I noticed that the "built-in" apps (i.e. bloatware) are actually just stuff left in the "system" dir which can only be accessed with root permission. So they are NOT store in "ROM" per se, but more like "part of boot rom".
I have to find explanation on how an app is loaded, but that helps...

Aha, so that's the term they used... Application Lifecycle.
http://www.youtube.com/watch?v=ITfRuRkf2TM
Okay, I take back what I said. Apps are loaded into RAM, but HOW things are allocated wasn't that clear.
From what I understand, apps, when they are killed by system, some exit gracefully by writing their instance "state" (data and cache) to app storage. Some just exits.
Browser will write the URL, for example. When the browser is "resumed", the process is loaded, then the instance loads back the URL and it's as if nothing happened.
I'll have to revise the paper, AND I haven't figured out what to say about swap and compcache yet.

Made some corrections.
On 256MB machine, 30MB is used by deep system buffers (not part of OS), another 32 for OS cache, so about 190 or so is available the OS itself to load apps and services, and just the default gapps, system, phone, and so on is about 60MB. So a fresh clean phone should ahve no more than 120-130 MB free. If you load a couple apps with autostart services, it'll quickly drop below 50MB.
http://stackoverflow.com/questions/2298208/how-to-discover-memory-usage-of-my-application-in-android

Another piece of the puzzle... The numbers at the bottom of "Manage Services" is as explained below:
(quoting from http://android-developers.blogspot.com/2010/02/service-api-changes-starting-with.html )
"Finally, along the bottom of the screen are some obscure numbers. If you know how to interpret them, this gives you a lot of information on the memory status of your device:
* Avail: 38MB+114MB in 25 says that the device has 38MB of completely free (or likely used for unrequired caches) memory, and has another 114MB of available memory in 25 background processes it can kill at any time.
* Other: 32MB in 3 says that the device has 32MB of unavailable memory in 3 unkillable processes (that is, processes that are currently considered to be foreground and must be kept running)"
The order is reversed in Android OS 2.2. Mine says
Other: 75MB in 5 Avail: 18MB + 20 MB in 3
Which should mean 75MB in 5 unterminable tasks, 18 MB free (or can be freed easily), plus another 20 MB used by 3 processes that can be killed to free up.
ProCrank says...
39911K System_server
15756K acore
12982K swiftkey
10136K DIY Screensaver (lock screen)
9392K Phone (system)
9093K ATKfroyo
6834K Terminal
3984K JuiceDefender
3785K Screebl
3482K system MMS
3329 SeePU
3244K Bluetooth
3199K SetCPU
1979K Zygote (which is Dalvik init)
1425K Mediaserver
and the rest is native system code well under 1MB in size.
If you add System_server, Phone, Zygote, Acore, and foreground app (terminal and procrank) you get about 75MB. It would be nice if that screen TELLS you which program it considers to be unterminable, but, oh well...

[Q] How to make Swap Partition For Galaxy Tab Plus

Hi
How can i create Swap Partition for increase RAM on Galaxy tab plus?
I find guide for other device, can`t find for Gt 6200
Thanks for help...

hmr007 said:
Hi
How can i create Swap Partition for increase RAM on Galaxy tab plus?
I find guide for other device, can`t find for Gt 6200
Thanks for help...
Click to expand...
Click to collapse
you can;t and should never need to.
You have 1 GB of RAM more than enough for any application.
Swap has not been used since Froyo I think . Since OG phones with 300 mb RAM.
Not used not needed

DigitalMD said:
you can;t and should never need to.
You have 1 GB of RAM more than enough for any application.
Swap has not been used since Froyo I think . Since OG phones with 300 mb RAM.
Not used not needed
Click to expand...
Click to collapse
Thanks for replay
but this 1GB (830 MB Actually) full after open 4-5 program or 2 game And Android close automatically other Application And last States!
I Want to save last States of other program Anyway until i Close program manually
For example Chrome close tabs after open 4-5 program and when i visit old tabs , it reloaded again!

hmr007 said:
Hi
How can i create Swap Partition for increase RAM on Galaxy tab plus?
I find guide for other device, can`t find for Gt 6200
Thanks for help...
Click to expand...
Click to collapse
Hi. Easiest way is to download Swapper2 from the PlayStore.

viper001 said:
Hi. Easiest way is to download Swapper2 from the PlayStore.
Click to expand...
Click to collapse
Only if you want to slow your tablet to a crawl.
Why would you want to swap very fast RAM with very slow SD memory? No need and a really bad idea.

DigitalMD said:
Only if you want to slow your tablet to a crawl.
Why would you want to swap very fast RAM with very slow SD memory? No need and a really bad idea.
Click to expand...
Click to collapse
agree. but, it looks like he's more concerned with multitasking.
it always depends on the user. let him try it first and let him decide what's acceptable for him.
Besides, "slow your tablet to a crawl" is an exaggeration.

viper001 said:
agree. but, it looks like he's more concerned with multitasking.
it always depends on the user. let him try it first and let him decide what's acceptable for him.
Besides, "slow your tablet to a crawl" is an exaggeration.
Click to expand...
Click to collapse
That won't help multitasking , Android already has an efficient memory management system. That OG swap app was for Froyo phones that only had about 300 mb to run the OS and apps. No longer applies. And since there are no true multi=tasking apps. IE you can;t run two foregrounds apps. ..... , you can never fill up RAM

DigitalMD said:
That won't help multitasking , Android already has an efficient memory management system. That OG swap app was for Froyo phones that only had about 300 mb to run the OS and apps. No longer applies. And since there are no true multi=tasking apps. IE you can;t run two foregrounds apps. ..... , you can never fill up RAM
Click to expand...
Click to collapse
OK. "Task-Switching" then .
Agree that android memory management is "efficient". the problem is that when it runs out of memory the app at the "back" of the stack gets "killed". data is saved for that app so when it's called back up, it "seems" like it was running all the while.
So, as per the OP question, since his problem was that his web pages keep reloading, ie app was killed due to memory constraints, his idea is to increase the RAM or in this case adding virtual RAM via swap.
It's not a bad Idea, since the amount of RAM is virtually increased, then the amount of apps that can be in RAM at the same time is also increased.
FYI, not only for froyo, i use swap for my NEO V running ICS. made DEAD SPACE run better than without swap. :good:
Haven't encountered a need on the P6200 though. Ofcourse, there must be a reason why 2GB RAM devices are now available.

there is not reason that swapping would make your tablet run better, none.
Because as of ICS , and with 1gb+ ram, you are emulating and interfering with what Android (linux) already does .
you have one foreground task and whatever idle tasks and then unused apps that are retained in RAM until they are needed or another apps needs space and they are removed from RAM. Then they reside on SD memory so what advantage does swapping to SD memory give you, none, in fact it adds a extra useless step .
SO Android attempts to keep RAM 80% used.at all times. If you look at the process logically, I do not believe can lay out a scenario by which the swapper apps beings any benefit to current Android systems.

DigitalMD said:
there is not reason that swapping would make your tablet run better, none.
Because as of ICS , and with 1gb+ ram, you are emulating and interfering with what Android (linux) already does .
you have one foreground task and whatever idle tasks and then unused apps that are retained in RAM until they are needed or another apps needs space and they are removed from RAM. Then they reside on SD memory so what advantage does swapping to SD memory give you, none, in fact it adds a extra useless step .
SO Android attempts to keep RAM 80% used.at all times. If you look at the process logically, I do not believe can lay out a scenario by which the swapper apps beings any benefit to current Android systems.
Click to expand...
Click to collapse
You actually pointed out the reason why the Original Poster wanted to use swap. he wanted his currently "unused" browser app to reside in ram, and not get killed. in this case it will be in virtual ram.
I agree with all your points. and I don't use swap on my tablet (P6200) haven't had a need, but i do use it on my phone(Neo V, 512 RAM, 384 useable).
All i'm saying is let him try. it's possible that he is hitting the limit on his Tablet. I know, cause it's easy to hit the limit on my phone that i'm very sure swapping works. e.g i can now switch between, Chrome, Facebook, Email, What'sUp, answer a phone call, send a text message and come back to Chrome (which has three open tabs BTW) without Chrome "reloading" those same three tabs. i wasn't able to do this before i starter using swap.
and yes, there's a bit lag but it's better than incurring cost of reloading a page each time, esp if your on a limited data plan.
One other thing that was not considered yet also are the OOM groups and Minfree. another option is Compcache.
The use of Swap really depends on the user and the way he uses his device. You can only see a benefit from swap if you consistently use up all your RAM. Which, if i understand the OP's problem correctly, is the case.

[Q] About swap space, this device and cyanogenmod

This may be a general question for all android devices or not but I was curious about adding swap space to this device. It has 1 gig of ram and many may consider that to be enough, and it might be. I have cyanogenmod 10.2 installed and tried to enable zram, 10% seems to be the best setting as anthing higher caused a game to pop up a notice saying something about low memory and defaulting to lower values. When I checked to see if zram was used however it turns out it was, about 25mb - 34mb after booting. The issue with zram is when multitasking with lecturenotes and moonreader, The tablet would reboot and my notebook that was open in lecturenotes would be missing notes I took or the settings would be greatly messed up, or both. This was with 10%.
I am thinking since it was used, it might be helpful to have an sd card for this reason, to aid in multitasking. This is important to me because I run several apps at once (I wish cyanogenmod had multi windows, and google wouldn't threaten over it). So the question is will there be a benifit to buying an sd card on ebay (class 10 of course) and using it as swap space. It seems this tablet might be on the cusp of the memory being enough. Also I am thinking this might help to future proof it a bit when updating to newer releases of gyanogenmod. The sd card I was thinking of is 4 gigs and may plan on having 1gb swap space (this tablet is for school and other work). The tablet has 32gb storage and that is more than enough for me (I am only using 3gb of space) so I wont need to add anymore storage.
I should also add that when multitasking without zram enabled, the tablet reboots less but still has done it, and so far nothing has been lost in my notebooks. I am thinking that the memory of 1gb is starting to reach its limit, with no apps running I am consuming about 600mbs of it.

vanquishedangel said:
This may be a general question for all android devices or not but I was curious about adding swap space to this device. It has 1 gig of ram and many may consider that to be enough, and it might be. I have cyanogenmod 10.2 installed and tried to enable zram, 10% seems to be the best setting as anthing higher caused a game to pop up a notice saying something about low memory and defaulting to lower values. When I checked to see if zram was used however it turns out it was, about 25mb - 34mb after booting. The issue with zram is when multitasking with lecturenotes and moonreader, The tablet would reboot and my notebook that was open in lecturenotes would be missing notes I took or the settings would be greatly messed up, or both. This was with 10%.
I am thinking since it was used, it might be helpful to have an sd card for this reason, to aid in multitasking. This is important to me because I run several apps at once (I wish cyanogenmod had multi windows, and google wouldn't threaten over it). So the question is will there be a benifit to buying an sd card on ebay (class 10 of course) and using it as swap space. It seems this tablet might be on the cusp of the memory being enough. Also I am thinking this might help to future proof it a bit when updating to newer releases of gyanogenmod. The sd card I was thinking of is 4 gigs and may plan on having 1gb swap space (this tablet is for school and other work). The tablet has 32gb storage and that is more than enough for me (I am only using 3gb of space) so I wont need to add anymore storage.
I should also add that when multitasking without zram enabled, the tablet reboots less but still has done it, and so far nothing has been lost in my notebooks. I am thinking that the memory of 1gb is starting to reach its limit, with no apps running I am consuming about 600mbs of it.
Click to expand...
Click to collapse
Well in my own personal testing i could not see any benefit while extracting 700mb archives under android with 4gb swap space on a 40mbs microsd card, while under full linux desktop with a same workload, swap differently helps keep the system smooth under heavy io load. The conclusion i drew was the android platform deals to memory management differently than the typical desktop os, due to slower emmc chips used as a boot disk for the majority of android devices using this slow, already bottlenecked memory as swap space doesn't make sense (not to mention the use of 2gb swap space on a limited 16gb storage etc), so android runs almost completely in ram, with stricter memory management and allocation allows android to run fine without swap space, although because of this, androids memory management makes little uses of available swap space

JoinTheRealms said:
Well in my own personal testing i could not see any benefit while extracting 700mb archives under android with 4gb swap space on a 40mbs microsd card, while under full linux desktop with a same workload, swap differently helps keep the system smooth under heavy io load.
Click to expand...
Click to collapse
I've been running my desktop without swap for the last 10 years, and as long as you have enough RAM for all your running programs, there will be no problem at all.
Extracting an archive is a mostly sequential operation (single read stream, single write stream), so it also doesn't benefit from caching, which could use the memory that is freed by swapping.

_that said:
I've been running my desktop without swap for the last 10 years, and as long as you have enough RAM for all your running programs, there will be no problem at all.
Extracting an archive is a mostly sequential operation (single read stream, single write stream), so it also doesn't benefit from caching, which could use the memory that is freed by swapping.
Click to expand...
Click to collapse
Ahh that makes sense. I wasnt sure if swap had an effect directly on the extraction, but seem keeped the rest system more stable/ smooth duing the process in the case of GNU/Linux, with swap off similar operations such as installing packages would more oftern lock the tablet up. Might be a placebo though
I also dont set swap on my Linux desktop, as it has plenty of ram but the benitfit of swap space is somewhat more noticable due to the lack of ram on the tf700.

JoinTheRealms said:
I also dont set swap on my Linux desktop, as it has plenty of ram but the benitfit of swap space is somewhat more noticable due to the lack of ram on the tf700.
Click to expand...
Click to collapse
I just want to share my user experiences on the swap space... It does seem to improve the tf700 with swap space due to the lack of RAM (1GB)..

Thanks for all the useful posts
Thanks for all the posts, I have my sd card on the way. I will post my experience when I get my sd card but I am sure it is safe to say there will be a benefit. I use linux to at home and have 8 gigs of ram on that computer, I lessen the swap after install to about 512mb because 8 gigs is more then enough. I leave some however just incase of any issues like ram going bad. On another computer in the house that has limited ram (1.5 gigs) I have enabled zram (384 mb) and added two old flash cards (1 gig each) to a pci raid card and those were converted to swap. I then altered the fstab to reflect the order of priority I wanted them used in. The reason is that when the swap is used from the hard drive, and the hard drive is being written to, can cause a slow down. So with the 2 flash cards at 1 gig each (the swap seen as 2 gigs) it seemed to speed it up. I just posted that because of the nix users and it seemed like a good plan to run it that way.

Ok, got the sd card
So I recieved the sd card today and applied the swap space to it using root swapper (max setting is 256mb, I figured i can find a way to increase it later if I need to). The defaut location in many of the swap applications will not work on this device however, the sd card mounts at /storage/sdcard1 in my case. So it has to be entered manually (might just be cyanogenmod). Also the device was picky when insalling the card, it would only say blank sd card or cannot read filesystem. I had to install the card in the dock, format it from cwm recovery, (vfat if I remember correct, ext2 and ntfs had issues, avoided ext3 and ext4 cause journaling will cause more wear and tear).
The sd card is a scandisk ultra sdhc uhs-1 8 gigs. From my research that is the fastest this tab can handle. I also use optimising programs like greenify (epic save everything app), pimp my rom (almost every tweak applied), and some pretty efficient tweaks in the settings as well. I also have HALO))) installed and working (epic multiwindow app that works with native programs and almost any rom).
The resuts:
I tested it many ways, I rebooted to see use (none was used because swap starts after boot), I opened apps normally (browsers and things), and it showed 9kb's was used. I then put it to the tests, I open four windows in halo, these were youtube, moonreader pro with a pdf ebook, lecturenotes (awsome note and handwriting app with tons of functions), and Supernote pro (not the best note app). Constantly switched between the apps and messed with settings with them open. The max of swap used was around 10mb(keeping in mind that when I switch windows the app(s) I leave get paused making it hard to tell actual usage because I had to swith the terminal and type "free". I then ran antutu bechmark and gpubench (my tab stills score pretty well) and got a little higher swap usage but not much.
As for the feel of it, it seemed to help when opening many windows in halo, this is the primary reason for my doing this. As for other more normal uses I really didnt see too much of a difference, I did test games however and they did seem a little better (could be placebo) but I am not really sure why they would except android cached other apps to free memory. Reopening apps seemed faster. Also because of apps like greenify my memory usage is decreased so I am sure typically swap would have seen more use.
The conclusion is that at this point I really didn't notice much of a boost for any normal use, but I will definately keep the swap space on due to the boost when using halo and not to mention that I will be updating to android 4.4 soon and it might need more memory. Swap at this point seems more like a pre emptive strike, but it does help with multitasking.

about swap
://androidforums.com/boost-mobile-warp-all-things-root/610449-ram-swapping-without-swapper2.html I actually followed a guide on android central and redid the swap file to 1 gig to swap instead of using a program, this worked better. (add http in front), when i disabled swap it was noticeable that there was a boost. then reenabled it this method.