This is now android works. The way I see this, this is very much similar to "pre-fetch" concept in windows 7.
I have a 6 GB RAM laptop. Base OS uses less than 1.5 GB of RAM. But like an hour or so when I see my RAM usage, its to the tune of 3-4 GB. What I have noticed is that my most frequently/recently used apps are loaded to RAM and kept there idle. Some amount of RAM is always kept free instead of using up all RAM. This way apps start faster. When I load a different memory heavy program, it pushes the existing one out and loads this.
More or less the same in android too. When u go to any task manager app n see the running apps, u'll notice that many of the apps loaded are the ones u use frequently.
These apps do NOT use any CPU. They are just loaded to memory and kept there for quick access.
When I boot up my phone I have like 190+ MB free RAM. Though left in standy mode, within an hour, I see my free RAM fall to 80-120 MB range. I never saw it go less than 80 MB. And the apps in memory are the ones I used the last time, and the ones I use all the time.
Even if u use a task killer to kill these "inactive" apps at intervals, they would be loaded again sooner or later. That's the principle of android. So by using task killers, though u feel u r freeing up memory, in fact, u r only draining ur battery. What's the use of memory if u r not using it effectively.
Don't worry abt free RAM amount. Let android manage it. Systems are intelligent enough these days.
Hope this helps. Below is more about the same in detail.
Android Memory Management
Android is a Linux based OS with 2.6.x kernel, stripped down to handle most tasks pretty well. It uses native open source C libraries that have powered Linux machines for years. All the basic OS operations like I/O, memory management, and so on, are handled by the native stripped-down Linux kernel.
How to use memory for each application
Android’s process and memory management is a little unusual. Like Java and .NET, Android uses its own run time and virtual machine to manage application memory. Unlike either of these frameworks, the Android run time also manages the process lifetimes. Android ensures application responsiveness by stopping and killing processes as necessary to free resources for higher-priority applications.
Each Android application runs in a separate process within its own Dalvik instance, relinquishing all responsibility for memory and process management to the Android run time, which stops and kills processes as necessary to manage resources.
Dalvik and the Android run time sit on top of a Linux kernel that handles low-level hardware interaction including drivers and memory management, while a set of APIs provides access to all of the under- lying services, features, and hardware.
Dalvik Virtual Machine Dalvik is a register-based virtual machine that’s been optimized to ensure that a device can run multiple instances efficiently. It relies on the Linux kernel for threading and low-level memory management.
The Dalvik Virtual Machine
One of the key elements of Android is the Dalvik virtual machine. Rather than use a traditional Java virtual machine (VM) such as Java ME (Java Mobile Edition), Android uses its own custom VM designed to ensure that multiple instances run efficiently on a single device.
The Dalvik VM uses the device’s underlying Linux kernel to handle low-level functionality including security, threading, and process and memory management.
All Android hardware and system service access is managed using Dalvik as a middle tier. By using a VM to host application execution, developers have an abstraction layer that ensures they never have to worry about a particular hardware implementation.
The Dalvik VM executes Dalvik executable files, a format optimized to ensure minimal memory foot- print. The .dex executables are created by transforming Java language compiled classes using the tools supplied within the SDK.
Understanding Application Priority and Process States
The order in which processes are killed to reclaim resources is determined by the priority of the hosted applications. An application’s priority is equal to its highest-priority component.
Where two applications have the same priority, the process that has been at a lower priority longest will be killed first. Process priority is also affected by interprocess dependencies; if an application has a dependency on a Service or Content Provider supplied by a second application, the secondary application will have at least as high a priority as the application it supports.
All Android applications will remain running and in memory until the system needs its resources for other applications.
It’s important to structure your application correctly to ensure that its priority is appropriate for the work it’s doing. If you don’t, your application could be killed while it’s in the middle of something important.
The following list details each of the application states shown in Figure (see the attached image) explaining how the state is determined by the application components comprising it:
Active Processes Active (foreground) processes are those hosting applications with components currently interacting with the user. These are the processes Android is trying to keep responsive by reclaiming resources. There are generally very few of these processes, and they will be killed only as a last resort.
Active processes include:
* Activities in an “active” state; that is, they are in the foreground and responding to user events. You will explore Activity states in greater detail later in this chapter.
* Activities, Services, or Broadcast Receivers that are currently executing an onReceive event handler.
* Services that are executing an onStart, onCreate, or onDestroy event handler.
Visible Processes Visible, but inactive processes are those hosting “visible” Activities. As the name suggests, visible Activities are visible, but they aren’t in the foreground or responding to user events. This happens when an Activity is only partially obscured (by a non-full-screen or transparent Activity). There are generally very few visible processes, and they’ll only be killed in extreme circumstances to allow active processes to continue.
Started Service Processes Processes hosting Services that have been started. Services support ongoing processing that should continue without a visible interface. Because Services don’t interact directly with the user, they receive a slightly lower priority than visible Activities. They are still considered to be foreground processes and won’t be killed unless resources are needed for active or visible processes.
Background Processes Processes hosting Activities that aren’t visible and that don’t have any Services that have been started are considered background processes. There will generally be a large number of background processes that Android will kill using a last-seen-first-killed pat- tern to obtain resources for foreground processes.
Empty Processes To improve overall system performance, Android often retains applications in memory after they have reached the end of their lifetimes. Android maintains this cache to improve the start-up time of applications when they’re re-launched. These processes are rou- tinely killed as required.
How to use memory efficiently
Android manages opened applications which are running in the background, so officially you shouldn’t care about that. This means that it closes the applications when the system needs more memory. However, most android users are not very satisfied with how it does its things because sometimes it leaves too many processes running which causes sluggishness’ in everyday performance. We can use advanced task killer/task manager and it does its job very well.
Source:
Code:
http://mobworld.wordpress.com/2010/07/05/memory-management-in-android/
NICE!!
diablo009 said:
This is now android works. The way I see this, this is very much similar to "pre-fetch" concept in windows 7.
I have a 6 GB RAM laptop. Base OS uses less than 1.5 GB of RAM. But like an hour or so when I see my RAM usage, its to the tune of 3-4 GB. What I have noticed is that my most frequently/recently used apps are loaded to RAM and kept there idle. Some amount of RAM is always kept free instead of using up all RAM. This way apps start faster. When I load a different memory heavy program, it pushes the existing one out and loads this.
More or less the same in android too. When u go to any task manager app n see the running apps, u'll notice that many of the apps loaded are the ones u use frequently.
These apps do NOT use any CPU. They are just loaded to memory and kept there for quick access.
When I boot up my phone I have like 190+ MB free RAM. Though left in standy mode, within an hour, I see my free RAM fall to 80-120 MB range. I never saw it go less than 80 MB. And the apps in memory are the ones I used the last time, and the ones I use all the time.
Even if u use a task killer to kill these "inactive" apps at intervals, they would be loaded again sooner or later. That's the principle of android. So by using task killers, though u feel u r freeing up memory, in fact, u r only draining ur battery. What's the use of memory if u r not using it effectively.
Don't worry abt free RAM amount. Let android manage it. Systems are intelligent enough these days.
Hope this helps. Below is more about the same in detail.
Android Memory Management
Android is a Linux based OS with 2.6.x kernel, stripped down to handle most tasks pretty well. It uses native open source C libraries that have powered Linux machines for years. All the basic OS operations like I/O, memory management, and so on, are handled by the native stripped-down Linux kernel.
How to use memory for each application
Android’s process and memory management is a little unusual. Like Java and .NET, Android uses its own run time and virtual machine to manage application memory. Unlike either of these frameworks, the Android run time also manages the process lifetimes. Android ensures application responsiveness by stopping and killing processes as necessary to free resources for higher-priority applications.
Each Android application runs in a separate process within its own Dalvik instance, relinquishing all responsibility for memory and process management to the Android run time, which stops and kills processes as necessary to manage resources.
Dalvik and the Android run time sit on top of a Linux kernel that handles low-level hardware interaction including drivers and memory management, while a set of APIs provides access to all of the under- lying services, features, and hardware.
Dalvik Virtual Machine Dalvik is a register-based virtual machine that’s been optimized to ensure that a device can run multiple instances efficiently. It relies on the Linux kernel for threading and low-level memory management.
The Dalvik Virtual Machine
One of the key elements of Android is the Dalvik virtual machine. Rather than use a traditional Java virtual machine (VM) such as Java ME (Java Mobile Edition), Android uses its own custom VM designed to ensure that multiple instances run efficiently on a single device.
The Dalvik VM uses the device’s underlying Linux kernel to handle low-level functionality including security, threading, and process and memory management.
All Android hardware and system service access is managed using Dalvik as a middle tier. By using a VM to host application execution, developers have an abstraction layer that ensures they never have to worry about a particular hardware implementation.
The Dalvik VM executes Dalvik executable files, a format optimized to ensure minimal memory foot- print. The .dex executables are created by transforming Java language compiled classes using the tools supplied within the SDK.
Understanding Application Priority and Process States
The order in which processes are killed to reclaim resources is determined by the priority of the hosted applications. An application’s priority is equal to its highest-priority component.
Where two applications have the same priority, the process that has been at a lower priority longest will be killed first. Process priority is also affected by interprocess dependencies; if an application has a dependency on a Service or Content Provider supplied by a second application, the secondary application will have at least as high a priority as the application it supports.
All Android applications will remain running and in memory until the system needs its resources for other applications.
It’s important to structure your application correctly to ensure that its priority is appropriate for the work it’s doing. If you don’t, your application could be killed while it’s in the middle of something important.
The following list details each of the application states shown in Figure (see the attached image) explaining how the state is determined by the application components comprising it:
Active Processes Active (foreground) processes are those hosting applications with components currently interacting with the user. These are the processes Android is trying to keep responsive by reclaiming resources. There are generally very few of these processes, and they will be killed only as a last resort.
Active processes include:
* Activities in an “active” state; that is, they are in the foreground and responding to user events. You will explore Activity states in greater detail later in this chapter.
* Activities, Services, or Broadcast Receivers that are currently executing an onReceive event handler.
* Services that are executing an onStart, onCreate, or onDestroy event handler.
Visible Processes Visible, but inactive processes are those hosting “visible” Activities. As the name suggests, visible Activities are visible, but they aren’t in the foreground or responding to user events. This happens when an Activity is only partially obscured (by a non-full-screen or transparent Activity). There are generally very few visible processes, and they’ll only be killed in extreme circumstances to allow active processes to continue.
Started Service Processes Processes hosting Services that have been started. Services support ongoing processing that should continue without a visible interface. Because Services don’t interact directly with the user, they receive a slightly lower priority than visible Activities. They are still considered to be foreground processes and won’t be killed unless resources are needed for active or visible processes.
Background Processes Processes hosting Activities that aren’t visible and that don’t have any Services that have been started are considered background processes. There will generally be a large number of background processes that Android will kill using a last-seen-first-killed pat- tern to obtain resources for foreground processes.
Empty Processes To improve overall system performance, Android often retains applications in memory after they have reached the end of their lifetimes. Android maintains this cache to improve the start-up time of applications when they’re re-launched. These processes are rou- tinely killed as required.
How to use memory efficiently
Android manages opened applications which are running in the background, so officially you shouldn’t care about that. This means that it closes the applications when the system needs more memory. However, most android users are not very satisfied with how it does its things because sometimes it leaves too many processes running which causes sluggishness’ in everyday performance. We can use advanced task killer/task manager and it does its job very well.
Source:
Code:
http://mobworld.wordpress.com/2010/07/05/memory-management-in-android/
Click to expand...
Click to collapse
Sweet!! Good Info.. But wrong Section. You should port this in the General Section to help all!
rickysa2000 said:
Sweet!! Good Info.. But wrong Section. You should port this in the General Section to help all!
Click to expand...
Click to collapse
Oh. I thought this belongs to Q&A.
Any mods here who can move this to "General" please.
This would be why when you open the built in task manager nothing or only your launcher shows up but when you open ATK multiple other programs are shown open, correct?
I found similar information while researching battery saver programs. I keep ATK when I have stubborn apps that are stuck because it is easier to get through than Android Task Manager but the auto-kill feature is always disabled. Good coverage of this info.
bclark said:
This would be why when you open the built in task manager nothing or only your launcher shows up but when you open ATK multiple other programs are shown open, correct?
Click to expand...
Click to collapse
Exactly! If all programs/processes show up, like they do in ATK, it could cause instabilities in the system when the user kills any important process knowingly/unknowingly.
trekie86 said:
I found similar information while researching battery saver programs. I keep ATK when I have stubborn apps that are stuck because it is easier to get through than Android Task Manager but the auto-kill feature is always disabled. Good coverage of this info.
Click to expand...
Click to collapse
Thanks you. Saw too many threads/posts with questions about ATK and killing tasks. So compiled this so they could all be directed to this thread.
I don't mean to go digging up old threads, but I just wanted to post my opinion here on this memory clearing ordeal.
After reading the entire thread, I am even MORE inclined to want to use ATK or something similar...
At the very bottom of the post, last paragraph, it reads -
How to use memory efficiently
Android manages opened applications which are running in the background, so officially you shouldn’t care about that. This means that it closes the applications when the system needs more memory. However, most android users are not very satisfied with how it does its things because sometimes it leaves too many processes running which causes sluggishness’ in everyday performance. We can use advanced task killer/task manager and it does its job very well.
Click to expand...
Click to collapse
Here's my take -
While there is no way to override Dalviks operations for application retention, at least while you're operating the device you can keep the memory clear by monitoring and assisting in clearing it out, manually; Which will in fact yield a performance boost for a duration of time. Based on the description of how Dalvik operates, this is true.
Exactly how long of a duration I don't know. But it is as obvious as it gets that while Dalvik memory management is indeed cool, it is far from perfect and definitely induces low memory situations that CAN in fact cause sluggish performance. That much is already known.
So, in my opinion, if you enjoy the absolute maximum performance out of your device, ATK or something similar is definitely NOT a bad idea. Though it has to be done manually and after a period of time applications are brought back into memory, clearing the memory before opening an application allows full memory access to that application and also inevitably reduces CPU load as it removes the requirement for Dalvik to "shove" other applications on idle off the memory to make room for the active applications.
Personally, I just use Task Manager. It seems much more effective at clearing the memory.
Well, there are times when my phone is on for abt a week or so without turning off or rebooting (the times when I resist flashing roms or kernels or modems) and still I hardly feel any sluggishness. And I do NOT use any task killers. I let android handle everything its way.
And there is a difference between cleaning up memory say once every couple days, and having ATK set up to free up memory every hour or two. The first one could be helpful while the second is a battery killer.
rickysa2000 said:
Sweet!! Good Info.. But wrong Section. You should port this in the General Section to help all!
Click to expand...
Click to collapse
why quote such a big post to tell this
come on
regards
strategist99 said:
why quote such a big post to tell this
come on
regards
Click to expand...
Click to collapse
^
Why necropost ?!? Come on !
(just messin with ya)
Sent from my SGH-I897 using xda premium
how about file expert's memory management options?
ok - i get what's being written at the top of this. however, i do wonder about being able to tweak things some, mainly because on file expert's memory manager there's several memory config options: gamer, multi-tasker, light user, whatnot.
i got a phone to fit in my pants pocket, so it doesn't come with tons of RAM. and it freezes quite a bit when swapping between apps. of course there could be many other reasons, but still...
file expert's options don't seem to be persistent, so it's hard to get a handle on which setting would work best. now - would there be a way of making persistent memory optimization changes? if, how?
what is an amount of free memory that would need to be there for things to be smooth? by ATK, i get south of 50Mb quite often, which seems low.
i don't really like ATK's auto-kill - don't know what it will kill, and it seems that a free memory kill-threshold would be better than one based on time.
zdoe said:
ok - i get what's being written at the top of this. however, i do wonder about being able to tweak things some, mainly because on file expert's memory manager there's several memory config options: gamer, multi-tasker, light user, whatnot.
i got a phone to fit in my pants pocket, so it doesn't come with tons of RAM. and it freezes quite a bit when swapping between apps. of course there could be many other reasons, but still...
file expert's options don't seem to be persistent, so it's hard to get a handle on which setting would work best. now - would there be a way of making persistent memory optimization changes? if, how?
what is an amount of free memory that would need to be there for things to be smooth? by ATK, i get south of 50Mb quite often, which seems low.
i don't really like ATK's auto-kill - don't know what it will kill, and it seems that a free memory kill-threshold would be better than one based on time.
Click to expand...
Click to collapse
Auto-kill is quite bad as the it kills processes that always reset.
As for your ram, you could run a Bigmem kernel. 50ram is fairly normal with regular processes and a couple extras. It all depends on what you use/run.
I would need your phone's setup to help you more towards it though.
xperia ray, snapdragon, 512Mb of RAM
don't know what bigmem kernel is or would do. i'm a noob.
the phone as above. list of installed apps courtesy titanium attached - except i've since killed ATK and now trying autokiller, which is good at least for the SD-card parameter tweaks it gives. not sure about its memory management aspects, but at least they're persistent.
list of apps
here's the list - the forum didn't take .htm
and i'm on CM7.2.
EDIT/UPDATE: unrelated to killer apps, but for those of you who came to this thread to find remedies for RAM shortage - my observation currently is that the best thing you can do to yourself is to enable swap. that, and taking out the "play store" took me from 5 crashes a day to 1 - and after half a day of multi-tasking apps i can see up to 80Mb of swap in use, with 60Mb of RAM free, and the phone still running smoothly.
How to detect if an app is in background
In the above article it is said that the memory management is completely under control of Dalvik VM and Android runtime.
Is it not possible for a device driver to intelligently check if any app in background and release memory (allocated inside driver).
onStop(): All the rendering is stopped.
Is it possible to check some app state value to see if app in background or minimized?
This is not the explanation of memory management but process management
【APP】Optimize Tool Box(15 powerful functions)
Thanks to caotiantupi :angel:
Description:
Android Optimizer is a Swiss Army Knife for your mobile phone. Top 15 functions makes you manage your phone easily, effectively and efficiently.
This powerful app has 9 sections, 15 functions such as Device scan, Quick settings, Startup manager, App manager, Program manager, Cache cleaner, File explorer, Power saving settings, and Device infor. Those powerful and comprehensive tools form a 360 angle protection for your Smartphone can always keep your Smartphone in the best state!
Features:
1.Device scan: Provide full scan for your mobile phone. One click to optimize Installed apps, Auto start apps, Running apps and Cache. Show CPU, RAM, ROM,SD, Signal, Speed, and Battery status.
2.Apps sort: Custom category for your apps to manage easily.
3.General and advanced settings: Quick access to set ring mode, volume control, input settings, screen rotation, WIFI, Bluetooth, security, APN and so on.
4. Widget：Add widget to homescreen, easy to switch WIFI, Bluetooth, airplane mode, auto rotate, cache cleaner and much more.
5.Startup manager: Clean useless apps when startup, which can free memory, speed up running speed and save power.
6.Uninstaller:Support batch uninstall unwanted apps .
7.Installer: Install apk files from SD card.
8. Sort apps: Easy find apps to uninstall by installed time, size, or name .
9.Program manager: Display all running apps and services, kill unwanted running apps and running service. Ignore list can protect fatal apps and services.
10.Cache cleaner: One click to delete all cache to free more memory.
11.Message clear: List all your messages, contacts and strangers. one click to delete messages..
12.File explorer: Manage mobile phone and SD card files: view, send, move, copy, rename, delete and add files.
13.Power monitor : Monitor running apps’ battery status. Huge power consumptive apps can be sorted out and killed.
14.Power save: Adjust screen brightness, timeout, turn off WIFI, Bluetooth, GPS, auto-sync, background data.
15.Device information: Display mobile phone’s information such like CPU, model, RAM, SD card, memory, screen, operator, network type, IMEI, roaming status, system version, and kernel version…
V2.0.2 updates:
1 Add Startup time notification selection. Notification disabled by default.
2 Add single item detailed optimization result.
3 Add notifications to show whether installed apps can move to SD card.
4 New process ending rules, release memory completely.
5 Fix accidental delete problems in deep clean. The next version will be more accurate.
6 Add more functions in Quick settings.
7 Fix Compatibility problems in some devices.
8 Fix some tiny problems.
Download : Here
THX i try
I have installed dozens of apps on my Galaxy Ace and I think it's becoming too much for the poor device. I found out it frequently reboots because of RAM shortage. I tried killing all running apps, but all the memory-hogging services will just restart themselves, which also drains my battery.
So, is there a way to permanently disable Android services, other than to remove the corresponding apps? I don't need Google Maps running in the background (I don't care for tile caching), nor do I need Google Play to check for updates, yet they are active all the time and consume ~25MB of RAM, which makes the difference between freezing and a snappy phone.
Disable/force stop the apps that you do not use from the manage apps option in settings. If you are rooted, use titanium backup to get rid of apps that you don't use. Remember, do not disable any android system service unless you know what it is. You might get into trouble.
Sent from my GT-S5830 using xda premium
Try this...
Use RAM managers, decrease VM heap size and remove JIT also use root startup managers to avoid apps from starting automatically other then system apps.
try autorun manager..
disable useless apps which constantly runs on background and auto starts after killing.
best one so far..
The app 'Greenify' is a marvelous work by oasisfeng
This is the original thread : http://forum.xda-developers.com/showthread.php?t=2155737
Playstore link : https://play.google.com/store/apps/details?id=com.oasisfeng.greenify
*Why am I sharing this app?
Because this is going to help those who are running android 4.x or higher, having a feeling that our phone's ram and battery is not enough and still not aware of the process 'Greenifying'
*Are you depending on the process 'freeze' & 'unfreeze' to save your space and feeling it as little inconvenient to do it every time you use the frozen app ?
Then Greenify is the solution.
*This is the definition of Greenifying an app.
"Greenifying an app implies that you are aware that all the background functionality of this app will become out of service during the hibernation except when you are using this app:
Greenify helps you identify and put the bad behaving apps into hibernation when you are not using them, to stop them from lagging your device and leeching the battery, in an unique way! They can do nothing without explicit launch by you or other apps, while still preserving full functionality when running in foreground, similar to iOS apps."
When I read the above I was like " wow, this is the thing that I was searching for ! "
*It is designed and implemented in extremely light-weight, with an average RAM footprint at 2M in total, and nearly zero CPU and battery consumption.
Things to remember :
# The background functionality of the greenified apps will be disabled. The background functionality includes but not limited to:
> Persistent background services
> Broadcast receivers, which respond to global device events, such as network state change, SMS reception.
> Alarms, which activate background task at specific time or interval.
> Widget update. Widget should display but never update because periodic update involves background task.
> Push messages. Push is also disabled since it would activate background task on Android, unlike iOS which just shows up messages to user.
>Please DO NOT greenify alarm clock apps, instant messaging apps unless you never rely on them. Please be sure to verify the impact of greenified apps on which you heavily relies.
# not supported for Android 2.x
In my opinion, this app does what it says.Hope this will be helpful.
For more details, visit the original thread. :good: To the developer of this app.