What exactly is IO? - Asus Transformer TF700

Can someone give me a precise definition and how it applies to the 700?
Feel free to troll me.
Sent from my 3d porn machine.

I/O is input/output, basically reading/writing to the flash memory.

It can mean a lot of things depending on context, but in this case it refers to how fast data can be written to or read from the device's flash storage. As a way to save on ram use, applications will sometimes write data to storage so it can easily access it later if needed.
For example, all web browsers written within in the last 10 years do this as a way to speed up loading on frequently visited websites. That's why the ANRs are most common in the browser, and why using hacks to run the browser completely from ram fix the issue on the Prime.
The problem is, if you have slow disk access (be it by hardware limitations or, as appears to be the case here, poorly written software) everything grinds to a halt until the current operation and everything that was backed up as a result gets finished.

Related

Lets Talk Memory

Been reading through searchs on threads re: memory, and found a few, but not a lot.
How much memory?
First I'd like to get to an understanding of what I see with the memory tool and what the device is supposed to have: Specs I've read say the Captivate comes wiht 512MB of memroy. And of course with Android 2.1, they say it will only recognze 256.
Now, I just installed Memory Usage, and it reports this:
When I first boot up, and run it to check memory, I get these readings:
Total: 325MB Avail: 103MB
Active: 116MG Inactive: 141MB​
And it seems to vary from boot to boot.
I don't understand what I'm seeing in those readings. I presume the 325 is the total memory that is referenced when we say the memory is 512, but 256 availble. So why am I seeing 325?
Apps, Task Killers, et al
Moving on to a controversial topic. I have experimented with this a bit, and read quite a few posts with varying opinions on the topic. In general a person can say who knows who is right. But, it would seem that the information from a Google Resource talking on the subject officially in an interview, that we should assume they are right.
What did they say? (Sorry, I don't remember where the article was): Don't need task killers. Talked a lot about how memory is handled by Android.
During reading all that I installed one, and it seemed that what I was experiencing was the opposite like many others: memory shrinking; kill some tasks; turn on auto killer, and memory stayed considerably higher.
But after installing Juicedefender (per this interesting thread ) and messing with a bunch of more stuff I was starting to have freezes, lags, etc. (We've all heard that before). But then I somewhat am expecting to ultimately have to hard reset after doing all my experimentation.
But, after having someone in that thread say they weren't having much help from teh Auto killer, told me to remove it and see how it goes. I was thinking that my work in Juicedefender was causing my locks. When I did the things per that thread, my free memory jumped to 141, and later 151.
So, when its all said and done, I find the memory to not be consistent from one boot to the next. I find that sometimes there is a long list of apps that load at boot. I don't understand why some of the apps load at boot. I see Vlingo Voice in memory twice; I see Tapatalk Pro loaded. Earlier I saw several more.
This is long enough for one post. Curious what others have to think.
I use ATK to kill apps once i'm done with them.
when ever I'm done with an app i usually do this (ocd) and I keep my memory up near 190mb.
people can say what they will it all depends on your phone's real world usage. I saw a benefit. but lets not forget, even 2.1 has a stock task killer. so it's not like you have to get a specific app
from what I understand, 512mb is installed, but only 315 is accessible with 2.1 Eclair. when 2.2 Froyo is released then it will be able to access the full amount of memory.
Now, all I can say is that if I don't use Auto Killer, the memory keeps getting smaller and smaller and the phone gets to where it won't work. And with Auto Killer, I still ultimately need to do the same thing. I don't know what to think about this.
Another strange thing: when I first reboot it, and go in and look at what is loaded with Auto Killer, its a long list of programs.
Any idea whats up with that?
the way I understand it is that android tries to keep at least 90mb buffer between how much memory your using, and your max. then when you go into the 90mb it runs a garbage collector or starts dumping multitasked apps or something
then again it might only be doing that for apps and not processes
maybe someone with more knowledge can confirm/correct me?

[Q] Making Swapfile on Gtab 7+?

hi guys,..
i want to ask is there any way i can make swapfile on gtab 7+ running hc 3.2? or there is no posibility to make swapfile on honeycomb? i've tried to make the swapfile using dd command from terjinal, but somehow im stucked on setting permission for the file, the file i've created always have special permission that i can't change to rw-r-r, it always stayed rw-rSw-r, im a newbie on linux things, and willing to learn.
any help really appreciate.
thanks.
Okay, you say that you're a newbie to linux. That's fair and reasonable. I'm going to try and teach you some things by way of asking questions. They might sound like I'm attacking you, but I'm not...
Do you know you are trying to create a swap file? What do you hope to gain by doing so?
Is this one of those mythical magical things that someone claims will make the tablet run 50395920 times faster, allow it to brew coffee, and make your car get better fuel mileage?
...and some answers...
Within the android environment, a swap file is a BAD THING. The entire system is designed to drop stuff out of memory if/when it needs more memory, and the overhead of a swapfile will cause more harm than good.
Take care
Gary
garyd9 said:
Within the android environment, a swap file is a BAD THING. The entire system is designed to drop stuff out of memory if/when it needs more memory, and the overhead of a swapfile will cause more harm than good.
Click to expand...
Click to collapse
It's not that dramatic. Most of "the overhead of a swapfile" is overhead you're already committing to by utilizing a VMM (Virtual Memory Manager). The Dalvik VM doesn't do a whole lot of its own memory management so implementing a swapfile at the OS level, which is what the OP is looking to do, wouldn't have a huge impact on performance.
The only time where you'd have any real overhead of maintaining a swapfile is when memory is full and the OS pages out memory to disk. But remember that the alternative is to close down the process and run some garbage collection. Both are intensive actions - swapfile is I/O intensive while GC is CPU and memory intensive - so you're really trading one source of overhead for another.
To answer the OP's question, it sounds like you haven't rooted the tab. You would need to be root in order to change the perms as you described. If you are rooted, make sure you're using the right command to set permissions - I haven't tried this specifically on Android but from my *nix experience, the command you want is chmod 644 <path to file>
---------- Post added at 09:24 PM ---------- Previous post was at 08:39 PM ----------
Almost forgot, what kernel are you using?
im using stock kernel 2.6.36, kk6 rooted. i've tried to chmod the swapfile, but still cant change the permission, i usually use root explorer to change the permission, but now it doesn't take effect. the file permission r8 now is rw-rwSr--, the "S" thing is making the swap cant be aplied (i guess).
back there when i use optimus (gingerbread), swapfile is default from stock rom. is it have something to do with honeycomb?
thanks for your reply.
garyd9 said:
Okay, you say that you're a newbie to linux. That's fair and reasonable. I'm going to try and teach you some things by way of asking questions. They might sound like I'm attacking you, but I'm not...
Do you know you are trying to create a swap file? What do you hope to gain by doing so?
Is this one of those mythical magical things that someone claims will make the tablet run 50395920 times faster, allow it to brew coffee, and make your car get better fuel mileage?
...and some answers...
Within the android environment, a swap file is a BAD THING. The entire system is designed to drop stuff out of memory if/when it needs more memory, and the overhead of a swapfile will cause more harm than good.
Take care
Gary
Click to expand...
Click to collapse
thanks m8 for your lighten up of linux, i really appreciate it. just from my experient when im using optimus (gingerbread) i never felt lack of memory when using multitasking (it only has 512mb ram). but now when i using gtab (with 1gb ram or 778mb?) first it fast on multitasking but about 10 minute later it getting slower, when i check with task manager, it only has 80mb left??
is it me or is it gingerbread have better ram management than honeycomb, and so if it is, im trying to make swapfile in hope that its getting better. i use v6 supercharger, kill all proccess when it turn to standby by automatic, overclocking to 1,6ghz, but still i can make the ram more efficient when running on multitasking.
hope you understand for what im going to achieve.
thanks.
h2g2 said:
It's not that dramatic.
Click to expand...
Click to collapse
Are you suggesting that using an OS-level "generic" swapfile on flash memory is better or even equivalent to using a system/purpose built solution?
The linux kernel has no way to know if the memory its swapping out is even needed anymore. The android system, however, does know this - and will often discard allocations.
Let's say you run two applications: email and the browser. The browser has several pages loaded with flash, and lots of memory intensive stuff going on. Also in memory is the code that syncs your email in the background and several other "non critical" services (such as SMS, latitude, etc.) and a few critical services (such as some wifi support, display support, framework, etc.)
Keep in mind that if android requests memory, and there's a swapfile, the kernel will claim it has memory backed by swap... So given a large enough swapfile, the kernel will never tell android that it's running short on memory...
Given the above situation, the user now wants to run Angry Birds. There isn't enough physical RAM to support all of the above in memory AND Angry Birds. What will happen?
If there's no swapfile, android will see there isn't enough RAM to support it, and simply drop the browser and email client from memory, but keep the services in memory. Angry birds loads, and the user is happy.
IF there IS a swapfile, however, then android will see that there is RAM to support AB along with everything else in memory, and just load Angry Birds. When that happens, the linux kernel will have to swap pages of memory out to the flash memory. The KERNEL doesn't know the difference between the email client, the email service, the browser, or any other "non-critical" service. All those memory pages are flagged the same. So, perhaps the browser gets swapped out. (wasted cycles - it could have been discarded.) The email client is retained in RAM, but the email service is swapped out to flash. Angry Birds loads. 5 minutes later, Angry Birds freezes and gets jumpy... why? Because the email service has to be swapped back into RAM, and something else swapped out in its place. This time it was latitude. A few minutes later, latitude wants to update your position, so the same thing happens. What gets swapped this time?
Why spend the cycles swapping things in and out of RAM? There is plenty of memory on these devices to support all the services and memory hungry games. If some game has a memory leak, you SHOULD be getting errors from running out of memory and NOT blissfully swapping things to flash.
I'm not going to tell people how to use their devices. I'm going to try and give them advice, but I certainly can't force people to take it. As a matter of fact, I'll even encourage the technical minded to explore and break things to learn on their own.
However, when a person asks the question I see in the OP, and admits that they are new to linux, then I suspect that they aren't technically minded and exploring, but blindly following the "suggestion" of someone else who promises all kinds of silly things. It reminds me of someone who disabled kernel panic reboots and claimed that it was a tweak to make the system more stable... and had many people actually believing that.
There's a good reason why google hasn't enabled swapping, and there's even less of a reason with devices that come with 1GB of RAM.
Take care
Gary
---------- Post added at 01:45 AM ---------- Previous post was at 01:25 AM ----------
danielkaboom said:
is it me or is it gingerbread have better ram management than honeycomb, and so if it is, im trying to make swapfile in hope that its getting better. i use v6 supercharger, kill all proccess when it turn to standby by automatic, overclocking to 1,6ghz, but still i can make the ram more efficient when running on multitasking.
hope you understand for what im going to achieve.
thanks.
Click to expand...
Click to collapse
First of all, try the same thing without that "supercharger" script. I've made clear my thoughts on that. In this case, using that script may or may not be allowing HC to do what its designed to do in regards to memory management. I'm not saying you should delete it - but to run tests without it.
If you are running low on FREE memory, that's not a bad thing. What good is the memory doing if it's not being used? Android will let an unused application linger in RAM as long as they wants so long as nothing else needs that RAM. As soon as something else needs that RAM, those unused apps will be purged (garbage collection.)
Having a swap file directly contradicts any effort to purge things from memory. A swapfile will encourage the system to swap things to flash as virtual memory. Sure, your "free memory" number might be bigger, but it will slow the system down when it's swapping things out to and in from flash memory. (A blunt question Are you chasing numbers or actual performance?
How do you expect to make memory MORE efficient by always having it be unused? Memory that's not being used is wasted. If my desktop machine (that has 16GB of RAM) has only 6GB being used, then I have 10GB of RAM wasted. I'd rather that memory be used to store an application I might go back to using, or used as cache. Completely unused RAM is completely wasted RAM.
I understand that you might be caught up in the whole thing with overclocking, having as much free RAM as possible, and having nice benchmark numbers. The thing is.. NONE OF THAT MATTERS.
Want higher benchmark numbers? I can make you a kernel that will give you insanely high numbers. Your device will suck for actual use, but you'll get high benchmarks.
Want a big "free RAM" number? Never run any apps, never get email, don't do anything at all with the device. It'll be an expensive paperweight, but you'll always have lots of free (and completely wasted) RAM.
Try this: make a backup of your system and then go back to stock. Use your tablet in a factory state for a few days. Then root it and disable some of the things that might be chewing the battery. Don't overclock, don't install scripts, and don't install a custom kernel. Use the device like that for a while. Actually USE the device - don't benchmark it, check task managers, etc. Just use it.
Now, how does it feel? No script, kernel, or anything else will make a dramatic performance increase. They can (and often do) make things slower, however. (That's why I'm very careful about modifications I make to my kernel...)
After using it stock for a few days, come back and tell us what you think - what you wish would be better in actual day to day use. (Again, benchmarks and numbers don't mean much...)
Take care
Gary
yes Gary,...to be honest, im blindly follow every1 that claims can tweaks or anything like tha, but when i tested it and using it, if its making my device getting "better" i kept it, if its making it worse than before, i let go.
in my opinion, slow, fast or faster is relative, it depends on every1 needs. for me loading game such as finalstrike hd in 5 sec is fast, but maybe different to others by loading it 20-30 sec is acceptable.
but if you said swapfile is bad and will only making it worse, then i'll accept that, but after im testing it. for me, sugar is not sweet until my tounge said so, no offence.
again, thanks Gary for the explanation, thanks for opening my mind.
edit : ill try to follow your instruction first.
You should do what you feel like, but please don't get caught up in lots of people telling you that they have magic bullets to fix things (that really aren't even broken.)
That being said, you are having a technical problem and I just can't resist information sharing.
What directory are you trying to create the file in? /sdcard (or /mnt/sdcard) won't work.
Try /data
(/mnt/sdcard == /sdcard.. and they will force certain permissions via fuse/vold.) Unlike GB, with HC /data and /mnt/sdcard use the same space. (/mnt/sdcard is actually a fuse from /data/media.) (In GB, /data space was very limited. That's not the case with HC.)
Gary
still failed,...:
- create a file in /data (named swapfile.swp), using terminal
# dd if=/dev/zero of=/data/swapfile.swp bs=1024 count=128000
- check from root explorer, the file is now created.
# mkswap /data/swapfile.swp
# swapon /data/swapfile.swp
swapon /data/swapfile.swp = Function not implemented
any sugestion?
edit : the permission is now can be change to rw-r--r--(thx Gary)..but its still failed to swapon,..
edit 2 : from what i've read from other pages and sites,..is it because "kernel not support"?
garyd9 said:
Are you suggesting that using an OS-level "generic" swapfile on flash memory is better or even equivalent to using a system/purpose built solution?
Click to expand...
Click to collapse
There is no "system/purpose built solution" - the Dalvik VM uses the Linux kernel VMM functions for low level memory management (http://developer.android.com/guide/basics/what-is-android.html).
The linux kernel has no way to know if the memory its swapping out is even needed anymore. The android system, however, does know this - and will often discard allocations.
Click to expand...
Click to collapse
Yes it does. The VMM knows which pages are active, which are inactive, and - if an application has called free() on a pages it previously malloc()'d, it will know which pages are expired.
In fact, the VMM will often know more than the Dalvik VMs because each application runs in its own Dalvik thread with its own dedicated heap. Any individual Dalvik instance will only know the disposition of the heap for its own application.
The VMM, on the other hand, has visibility of all Dalvik threads and will know which threads are idle and which are active, which Dalvik threads have run garbage collection and free()'d a portion of their heap, etc.
Keep in mind that if android requests memory, and there's a swapfile, the kernel will claim it has memory backed by swap... So given a large enough swapfile, the kernel will never tell android that it's running short on memory...
Click to expand...
Click to collapse
No, it won't. That's not how the swapfile works. What you're describing is more akin to memory-mapped file I/O, which is related (in that the VMM plays a role in managing that address space) but not at issue (it's a completely separate operation from memory allocation and de-allocation).
Memory is requested by giving the kernel a malloc() command. The VMM will then check its page cache (the size of which is constrained by physical memory - regardless of whether there is a swapfile or not) and look for available space. If space isn't available, then the VMM will look for pages marked as expired. If there aren't enough expired pages, it will look for inactive pages (pages allocated by processes that are idle or supsended).
At this point, the VMM will either 1) discard the contents of the expired and/or inactive pages until enough free pages are available (if no swapfile is available) or 2), write the contents of the expired and/or inactive pages to the swapfile before discarding them until enough free pages are available.
Note that the presence or absence of the swapfile has no bearing on what pages are chosen. And again, regardless of whether there is a swapfile or not, if there aren't enough expired and/or inactive pages to get rid of, malloc() returns a null pointer. In otherwords, you will get out of memory errors even with a giant swapfile.
Given the above situation, the user now wants to run Angry Birds. There isn't enough physical RAM to support all of the above in memory AND Angry Birds. What will happen?
If there's no swapfile, android will see there isn't enough RAM to support it, and simply drop the browser and email client from memory, but keep the services in memory. Angry birds loads, and the user is happy.
IF there IS a swapfile, however, then android will see that there is RAM to support AB along with everything else in memory, and just load Angry Birds. When that happens, the linux kernel will have to swap pages of memory out to the flash memory. The KERNEL doesn't know the difference between the email client, the email service, the browser, or any other "non-critical" service. All those memory pages are flagged the same. So, perhaps the browser gets swapped out. (wasted cycles - it could have been discarded.) The email client is retained in RAM, but the email service is swapped out to flash. Angry Birds loads. 5 minutes later, Angry Birds freezes and gets jumpy... why? Because the email service has to be swapped back into RAM, and something else swapped out in its place. This time it was latitude. A few minutes later, latitude wants to update your position, so the same thing happens. What gets swapped this time?
Click to expand...
Click to collapse
So bearing in mind that the Linux kernel VMM is ultimately responsible for choosing what gets dropped or swapped out of memory and also bearing in mind that only inactive or expired pages are eligible to be dropped/swapped, we can see that the situation you describe will never happen.
The behavior of, from the user's perspective, what applications get shoved out of active memory (regardless of whether they end up in the swapfile or in /dev/null) doesn't change. In the same way that the Linux VMM will never drop pages associated with an active process (such as the email sync service, the Wifi driver, etc), the Linux VMM will likewise never swap these pages out either.
Why spend the cycles swapping things in and out of RAM? There is plenty of memory on these devices to support all the services and memory hungry games. If some game has a memory leak, you SHOULD be getting errors from running out of memory and NOT blissfully swapping things to flash.
Click to expand...
Click to collapse
Consider the scenario you spelled out previously - without the swapfile, the pages associated with the Browser app will get dropped and make room for Angry Birds. Good news: Angry Birds starts up faster.
With the swapfile, the pages associated with the Browser app will get swapped out to make room for Angry Birds. This will take longer since there's some file I/O involved. Bad news: Angry Birds starts up slower.
So what's the use case for the swapfile? What if you want to go back to the browser again? Without the swapfile, the Browser is gone. You have to launch it - the application binary needs to be read off disk, executed, the heap has to be re-allocated, re-initialized, and program data needs to be populated. The page you wanted is gone - you need to fetch that again. More waiting while it downloads from the server and the HTML code is rendered on the screen.
In this scenario, reading the heap back into memory from the swap file is actually more efficient than recreating it - even if you ignore the obvious benefit of not having to relaunch the app and reload the page, there's substantial overhead associated with relaunching the app.
So that's the use case - maybe it's not applicable to you if (although maybe someone who wants to go back and forth between Angry Birds and a cheat guide on a G1 might appreciate this) but if you are multitasking across several memory-intensive apps, then the benefit of not having to re-invent the wheel, so to speak, to recover the application state can outweigh the cost of paging the application state out to disk.
I'm not going to tell people how to use their devices. I'm going to try and give them advice, but I certainly can't force people to take it. As a matter of fact, I'll even encourage the technical minded to explore and break things to learn on their own.
However, when a person asks the question I see in the OP, and admits that they are new to linux, then I suspect that they aren't technically minded and exploring, but blindly following the "suggestion" of someone else who promises all kinds of silly things. It reminds me of someone who disabled kernel panic reboots and claimed that it was a tweak to make the system more stable... and had many people actually believing that.
Click to expand...
Click to collapse
I have no problem with dissuading people of the notion that some hack is going to instantly and unequivocally make their system better. But I think the proper response, especially on a forum like this, is to present the facts of the matter and not just a knee-jerk contrarion reaction. Simply dismissing the swapfile as a "BAD THING" doesn't really help the OP learn more about it, at the very least.
I'm with you on disabling kernel panic reboots, though. That's just stupid.
There's a good reason why google hasn't enabled swapping, and there's even less of a reason with devices that come with 1GB of RAM.
Click to expand...
Click to collapse
Maybe, maybe not. Android 2.1 and earlier didn't implement JIT. Android 2.2 and earlier didn't implement EXT4. Android 2.3 and earlier didn't implement GPU-accelerated UI compositing. Android 3.2 and earlier didn't implement ASLR. Does that mean these were considered undesirable by Google at one point in time? Or were they always on Google's list of things they wanted to do and they just hadn't gotten around to them yet?
---------- Post added at 01:56 AM ---------- Previous post was at 01:41 AM ----------
danielkaboom said:
still failed,...:
- create a file in /data (named swapfile.swp), using terminal
# dd if=/dev/zero of=/data/swapfile.swp bs=1024 count=128000
- check from root explorer, the file is now created.
# mkswap /data/swapfile.swp
# swapon /data/swapfile.swp
swapon /data/swapfile.swp = Function not implemented
any sugestion?
edit : the permission is now can be change to rw-r--r--(thx Gary)..but its still failed to swapon,..
edit 2 : from what i've read from other pages and sites,..is it because "kernel not support"?
Click to expand...
Click to collapse
Yes, the kernel needs to have swapfs support. If you've ever played around with EXT4 kernels or ROMs that required EXT4 kernels, for example, it's kind of the same idea.
It sounds like the stock GT7+ kernel does not have this so you will need to find a custom kernel that does. I'm going to go out on a limb and guess that garyd9's kernel does not support swapfs.
Without the kernel, you're out of luck.
Regarding your situation on your Tab, it sounds like you've got an app or two that's misbehaving. Have you tried throwing up a CPU monitor? It would be useful to know whether the slowdown is caused by the CPU getting busy, and whether this load is from a single app or not.
Thank you for explaining that. Are there any examples, other than the one you mentioned, in which Android would benefit from a swapfile?
reading both pros and cons about swapfile really makes my head spinning,... im trying to understand it little by little. thanks guys for the explanation.
and yeah, guess im run out of luck,..(cause i don't have enough skill to make the kernel on my own,..sigh).
thanks.
danielkaboom said:
reading both pros and cons about swapfile really makes my head spinning,... im trying to understand it little by little. thanks guys for the explanation.
and yeah, guess im run out of luck,..(cause i don't have enough skill to make the kernel on my own,..sigh).
thanks.
Click to expand...
Click to collapse
It is a complicated issue with lots of tradeoffs in both directions.
I'm still curious as to the specifics of your problems, though. Garyd9 is correct in saying that creating a swapfile may not help your particular issue but that doesn't mean there isn't some other way to fix it. We just need more information about what's going on on your tablet.
---------- Post added at 05:49 PM ---------- Previous post was at 05:29 PM ----------
nyarltep said:
Thank you for explaining that. Are there any examples, other than the one you mentioned, in which Android would benefit from a swapfile?
Click to expand...
Click to collapse
Fundamentally, it breaks down to a store vs. recalculate issue - do you store memory pages to the swap file and incur the storage I/O overhead or do you discard it and recalculate it later and incur the cpu and memory I/O overhead? All of these resources are in short supply on the GT7+.
A swapfile works best with applications that maintain steady states that can easily be swapped out and back in as needed. A swapfile is least effective for active background processes.
If, for example, you're running out of memory running too many apps in the background - think clients for sync services, streaming media, system monitoring, etc. - a swapfile is not going to help.
However, if you're running into situations where you are switching between multiple apps such as document viewers/editors, and are finding that you need to reload documents as the apps get silently killed in the background, a swapfile could potentially help.
The only real way to know is to test it but without a kernel with swapfs support for the GT7+, it's impossible to say for certain.
from the opinion, i guess using swapfile for backround process is useless, but using it to switching task (for example : im using browser with lot of pages and beside that im doing some paperwork on office aplication) will help a bit, am i r8? if its r8, then im willing to try using swapfile, because i already freeze/uninstall some aplication that running on backround but still give me lags, when i did the example above.
but again, im running out of luck,..until Garyd9 or any1 else kind enough to make kernel that support swapfs,...
thanks for both of you, for your effort to answering my noob question.
regards,
dan
PS : Gary, i've tried your instruction, and yes it makes my daily use better,...though im still curious using swap,...hehehe.
danielkaboom said:
from the opinion, i guess using swapfile for backround process is useless, but using it to switching task (for example : im using browser with lot of pages and beside that im doing some paperwork on office aplication) will help a bit, am i r8? if its r8, then im willing to try using swapfile, because i already freeze/uninstall some aplication that running on backround but still give me lags, when i did the example above.
but again, im running out of luck,..until Garyd9 or any1 else kind enough to make kernel that support swapfs,...
Click to expand...
Click to collapse
Background processes are fine to swap out if they're steady state, it's active background processes that aren't going to benefit from a swapfile.
However, the lags you're experiencing may continue to persist depending on what is causing those lags. A swapfile won't help if you've got a poorly-optimized app running, particularly one that is not efficient with memory allocations. It also won't help if the lags are caused by a Dalvik thread performing garbage collection on its heap (whether the app on that thread is efficient in its memory allocations or not).
My educated guess is that if you are experiencing lags while using an active, foreground application, then this is not a problem that will be fixed with a swapfile. On the other hand, if you are experiencing lags launching new applications or bringing background apps into the foreground, these types of lags may be reduced with the use of a swapfile though the only way to know for sure is to test it.
I don't have time for an indepth reply to h2g2, but I'll reply simply:
You seem to be knowledgable enough to recompile a kernel - so please feel free to pull my kernel sources and initramfs, turn on swapping (samsung has it disabled by default), and try it. Keep an eye on the swapping and memory stats, as well as what's being swapped, etc... You might be surprised.
(If I had time, I'd do the same.. I've been wrong before and I might be wrong again... )
In either case, Daniel, I'm glad that turning off all that excess crap helps. As much as we all complain about this tablet, it actually runs pretty good without many modifications. If you read the changes I've made in the p6210 kernel, you'll see that I really haven't done much to it. The most invasive change was adding stuff that Samsung didn't have in there (such as UV.)
Take care
Gary
garyd9 said:
I don't have time for an indepth reply to h2g2, but I'll reply simply:
You seem to be knowledgable enough to recompile a kernel - so please feel free to pull my kernel sources and initramfs, turn on swapping (samsung has it disabled by default), and try it. Keep an eye on the swapping and memory stats, as well as what's being swapped, etc... You might be surprised.
(If I had time, I'd do the same.. I've been wrong before and I might be wrong again... )
Click to expand...
Click to collapse
Just to be clear, I have no real stake in this except to make sure that the technical facts about the swapfile are presented properly. In much the same way that you've been frustrated hearing about people recommending that they disable kernel panic reboots, I also am frustrated when people have a knee-jerk "swapfile = terrible" reaction that is largely based on FUD.
That said, you're right, I should just test it myself when I've got some free time.
Dusted off my old Nexus One, loaded up a clean install of CM7 and installed a kernel with CONFIG_SWAP=y. I decided to go with a swap partition on my sd card rather than a swapfile but the effect should be the same.
I haven't had time to do extensive testing but so far but I can confirm that swap is working and I haven't yet noticed a major perceptible impact to performance of the device.
Code:
# free
total used free shared buffers
Mem: 403240 379288 23952 0 60
-/+ buffers: 379228 24012
Swap: 62696 27948 34748
# grep "pswp" /proc/vmstat
pswpin 192
pswpout 7059
---------- Post added at 01:37 PM ---------- Previous post was at 12:49 PM ----------
Been switching back and forth between apps for a while now, paying particular attention to apps like Google Earth and the Browser that load up lots of data.
One particular test that seemed to stress the memory subsystem was using the "Print this page" on multi-page articles on graphics-heavy sites like, e.g. Anandtech (had the Snapdragon S4 review up). With swap enabled, there was a delay of 1-2 seconds when switching back to the browser (no doubt from reading the appropriate pages back into memory) but without the swapfile, the session was gone and the page needed to be reloaded, which took much longer than 1-2 seconds.
Some caveats:
1) I used a rather small swap partition (64MB) compared to the amount of memory available on the device (512MB for the N1). This means that I didn't need to do too much tweaking to the lowmemorykiller settings.
2) I set swappiness to 100, which is intentionally a bit heavy-handed (default seems to be 60).
3) I did not tweak other settings such as dalvik.vm.heapsize, vfs.
_cache_pressure, page-cluster and, as mentioned in #1, lowmemorykiller/parameters/minfree.
Code:
# free
total used free shared buffers
Mem: 403240 390824 12416 0 36
-/+ buffers: 390788 12452
Swap: 62696 59684 3012
# grep "pswp" /proc/vmstat
pswpin 6061
pswpout 31228
h2g2 said:
Dusted off my old Nexus One, loaded up a clean install of CM7 and installed a kernel with CONFIG_SWAP=y. I decided to go with a swap partition on my sd card rather than a swapfile but the effect should be the same.
I haven't had time to do extensive testing but so far but I can confirm that swap is working and I haven't yet noticed a major perceptible impact to performance of the device.
Code:
# free
total used free shared buffers
Mem: 403240 379288 23952 0 60
-/+ buffers: 379228 24012
Swap: 62696 27948 34748
# grep "pswp" /proc/vmstat
pswpin 192
pswpout 7059
---------- Post added at 01:37 PM ---------- Previous post was at 12:49 PM ----------
Been switching back and forth between apps for a while now, paying particular attention to apps like Google Earth and the Browser that load up lots of data.
One particular test that seemed to stress the memory subsystem was using the "Print this page" on multi-page articles on graphics-heavy sites like, e.g. Anandtech (had the Snapdragon S4 review up). With swap enabled, there was a delay of 1-2 seconds when switching back to the browser (no doubt from reading the appropriate pages back into memory) but without the swapfile, the session was gone and the page needed to be reloaded, which took much longer than 1-2 seconds.
Some caveats:
1) I used a rather small swap partition (64MB) compared to the amount of memory available on the device (512MB for the N1). This means that I didn't need to do too much tweaking to the lowmemorykiller settings.
2) I set swappiness to 100, which is intentionally a bit heavy-handed (default seems to be 60).
3) I did not tweak other settings such as dalvik.vm.heapsize, vfs.
_cache_pressure, page-cluster and, as mentioned in #1, lowmemorykiller/parameters/minfree.
Code:
# free
total used free shared buffers
Mem: 403240 390824 12416 0 36
-/+ buffers: 390788 12452
Swap: 62696 59684 3012
# grep "pswp" /proc/vmstat
pswpin 6061
pswpout 31228
Click to expand...
Click to collapse
little of my understanding, if a swapfile is made in an external sd, the sd card must have good r/w capability (minimum required a class 6 sd card), what if the swapfile is made in internal sd (since GTab have 12gb planted chip memory), what is the effect?
and so,....would you be kind enough to build a kernel for GTab 7+ that support swapfile? and if you do, can you do with a flashable zip (which i can flash it through cwm recovery?
so i can answer my own question : swap or not to swap?
and of course if you have spare time
thanks
dan
danielkaboom said:
little of my understanding, if a swapfile is made in an external sd, the sd card must have good r/w capability (minimum required a class 6 sd card), what if the swapfile is made in internal sd (since GTab have 12gb planted chip memory), what is the effect?
and so,....would you be kind enough to build a kernel for GTab 7+ that support swapfile? and if you do, can you do with a flashable zip (which i can flash it through cwm recovery?
so i can answer my own question : swap or not to swap?
and of course if you have spare time
thanks
dan
Click to expand...
Click to collapse
I'm using a Class 2 8GB MicroSDHC card from Sandisk on my Nexus One for testing and it seems to be fine. I'd recommend using an external SD because it's replaceable and swap I/O will wear out your flash faster so you're better off segregating it.
I took a look at the state of the kernel source for the GTab7+ at the moment and it looks like the Samsung sources are out of date and a kernel built from the current sources won't run properly on the LA3 firmware (Garyd9 notes this in the thread for his kernel as well) so right now, building a custom kernel is a nonstarter for me because the LA3 firmware fixed some pretty major shutdown issues for me on my Tab.
Perhaps when the ICS sources are released, I'll take another look.

[Q] How to monitor read/write operations in Android?

Hi friends,
I believe the consensus around here is that the tf700 has terribly slow internal storage, which causes a lot of performance issues, especially when a lot of apps are running. As such, I would like to know if there is any app that can allow me to see in real time what apps are accessing the internal storage? I am looking for something like Windows Task Manager, which allows you to see all current running programs and their respective I/O operations.
Thanks for your help.

Performance questions - swap, RAM; Google Play Music

Hello!
I've been using XT1032 for a while as someone that's mostly new to smartphones - it's an upgrade after heavily worn out LG GT540. However after rooting it, installing official CM and updating to the latest nightlies every second day or so, I still have several problems. I'm sorry if there's too little detail in this post, I'll try to add detail later on.
First off, I don't understand how the storage space works. The phone is supposed to have 8GBs of internal memory, however only 5.5GBs are accessible to the user. Additionally, applications refuse to install when the system reports that there's ~400MBs of "space" left. Is this because of a partition being filled up? The Apps panel of system settings isn't specific what is taking up too much space and I'm afraid the DiskUsage app doesn't help either.
Second thing is the actual available RAM. It's supposed to be 1 GB, but Z-DeviceTest reports only 885MBs being available. Where's the rest? There's also swap of 255MBs that I don't know where it came from. I thought that on a low-end smartphone they wouldn't waste internal storage on swap.
There's a trick to increasing available storage space by linking the /cache folder to root. How does that work? How do I know if the folder is being used or not, and if it's safe to do this? DiskUsage doesn't show this folder normally, and when switching to it in root it's being 651MBs large, with "System data" taking up 11.2MBs and pds-CM10.img 3MBs. There's also recovery and backup folders, 56KBs and 16KBs respectively. Why is it this big anyhow, if it's not being used?
The most immediate problem, and the one that annoys me the most since I bought the phone for a certain purpose, is that Google Play Music is lagging terribly. It uses ~110MBs when I switch to the Running Apps screen from the settings quickly enough to check its stats, each song takes several seconds to load even on WiFi, no matter the quality, and the worst part is that even if it "loads up" it takes several additional seconds to scroll around it! It's not just the playing affected, the whole interface is sluggish. Screens take seconds to switch between each other, returning to the app after opening two applications makes it either "restart", where it still plays music, but you can see that the interface is now several screens back. How is it possible that in 2015 an operating system developer can't make a performant app that's not a game, that's not a video editor, but a god damn music player? The only quirk is that it's streaming the music from the net instead of playing a downloaded file. It has a cache that uses over 700MBs already, no excuses. I checked that with DiskUsage.

how to increase ram of android device

When you've had a smartphone for a while it can start to feel slow, and RAM — random access memory, which is where your phone stores its stuff as it's using it — can be part of the problem. If your phone doesn't have enough RAM it can struggle, but there are ways to address that. You can even create extra RAM without cracking the case or reaching for a soldering iron.
Find out how to increase your smartphone's RAM right here!
How to fix phone lag on Android
Android Lollipop tips and tricks
What is RAM (Random Access Memory)?
RAM is what your device uses when it's doing something. For example, when you're editing a photo both the photo and the app you're using to edit it are in the device's RAM; when you finish editing the photo is then saved to your device's storage so it can't get lost. The more RAM you have the more you can do, so for example you can have more browser tabs open, more apps running or more system features doing their stuff.
The problem with RAM is that it isn't always emptied properly, and apps don't always behave. Some apps and system processes run when you don't need them to, and others don't clean up after themselves when they quit. After a while those issues can produce noticeable results such as slow performance, lagging and stuttering, and the odd crash.
Like internal storage, RAM is a physical component of your device so you can't just stick more in. What you can do, though, is use it more efficiently — or use some clever tricks to create RAM from other kinds of storage.
RAM — shown here in desktop form — is physically limited in every device. Unlike PCs, you can't just stick more memory into your phone or tablet. / © Taringa
How to increase your RAM without root access
Now that you know ​​what RAM is, we'll show you how to preserve it. In this first part, we focus on tips for non-rooted devices. For those devices you can't magically add more memory, but you can make better use of what you've got. As a rule of thumb, the more your phone is doing the more RAM is being used, so if you can reduce what's running you can free up more memory for the tasks that really matter.
Limit widgets and live wallpapers
Widgets and live wallpapers are both pretty greedy when it comes to RAM usage. Many refresh often and occupy bandwidth, while some are continuously active. This can also cause your battery to drain faster. So remember to limit the number of them in effect to optimize your current available memory.
Animated wallpapers can take up a lot of RAM.
How to root your phone without voiding the warranty.
Disable applications
Some applications take up RAM even if they aren't currently being used, so you're getting all the downsides of unnecessary RAM use without anything to show for it. Organizing which apps should and should not be running in the background can take time, but it's worth it to improve your smartphone performance.
To disable an application, go to Settings and then Apps or Application Manager. Next, go to the All tab to get the list of all the applications currently on your device. To disable an application, tap on it, then tap Disable and confirm. Be careful not to disable everything and anything, unless you want to end up with an unstable system, but most apps that don't come pre-installed on your handset are pretty safe to disable (or delete entirely if you never use them).
Head to your device settings menu, then the apps page.
Next, tap on the app you wish to disable and tap Disable.
Disable animations
Animations often steal RAM and are quite inessential; you can manage these in the developer options. To enable Developer Options on your device, go to your Settings, then About Phone and then tap on the build number about seven times until it notifies you that you have become a developer. (Please note that this has no negative effect on your device, it just adds the developer options menu in your settings. You just need
???
tra_dax
Nice copy pasta
This is straight off Android Pit
HMpenguinify said:
This is straight off Android Pit
Click to expand...
Click to collapse
Yeah it is not even copied completely. The text is missing the last part
Why don't you post something from your own experience or your own thought, please don't copy from other sites.
I think it's called ram optimization and not increasing the ram. BTW.
max24328 said:
I think it's called ram optimization and not increasing the ram. BTW.
Click to expand...
Click to collapse
https://play.google.com/store/apps/details?id=com.swapit.expander.de&hl=en
Can't post from other sources without due credit. Thread closed.
Also given lower post count of OP, this is potentially posted to increase post count.

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