background apps and task killers

[sahands]

So there are a plethora of task killer apps, that shut down apps running in the background, with promises of speeding up the phone and improving battery life. But then there are many articles online that explain why they do more harm than good; essentially that android is not windows, that background apps in android are on pause and do not slow down the phone or drain extra battery.

https://www.howtogeek.com/166140/you-dont-need-to-install-a-task-manager-how-to-manage-running-apps-...

https://www.lifewire.com/does-your-android-need-a-task-killer-4147982

So it all makes sense, but then nowadays google has altered android to start killing background apps using the new Battery Optimization setting. So were those task killing apps right all along!?

[will13am]

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@srlawren wrote:

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@popping wrote:

When an app is killed forcefully without allowing it to gracefully releasing all allocated memory, over time, those memory will grow.  Your phone will slow down as your phone has less memory to work with.  Then, you need to restart your phone to record those memory.

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@popping memory leakage occurs while (poorly coded) apps are running.  Once they are killed off, the OS is free to reclaim that segment of RAM.  Killing processes does not slow down your system due to leaked memory.  

The real reason they say not to manually kill off your background apps in Android is becuase many/most apps consume more memory to bootstrap themselves (initialize by loading themselves into memory, loading some data, etc etc) than they do by just staying running.

Just like everything in life, there is no absolute, and either camp should just be viewed as a guideline.  In other words, there are exception where apps load very quickly (without consuming much power) but do use a lot of power (via wakelocks as @will13am noted, or via frequently using the radios to refresh data, etc) when left running.  And there are apps that do almost nothing when left dormant in the background but take a great deal of power to bootstrap. 

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Using the cellular radio excessively should be a thing of the past by now.  Hopefully all apps on the Android play store use GCM for sync.  Similar equivalent for iOS.  

[srlawren]

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@popping wrote:

When an app is killed forcefully without allowing it to gracefully releasing all allocated memory, over time, those memory will grow.  Your phone will slow down as your phone has less memory to work with.  Then, you need to restart your phone to recover those memory.

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@popping memory leakage occurs while (poorly coded) apps are running.  Once they are killed off, the OS is free to reclaim that segment of RAM.  Killing processes does not slow down your system due to leaked memory.  

The real reason they say not to manually kill off your background apps in Android is becuase many/most apps consume more memory to bootstrap themselves (initialize by loading themselves into memory, loading some data, etc etc) than they do by just staying running.

Just like everything in life, there is no absolute, and either camp should just be viewed as a guideline.  In other words, there are exception where apps load very quickly (without consuming much power) but do use a lot of power (via wakelocks as @will13am noted, or via frequently using the radios to refresh data, etc) when left running.  And there are apps that do almost nothing when left dormant in the background but take a great deal of power to bootstrap. 

[will13am]

Apps that run in the background can cause wakelocks.  This is what consumes a lot of power.  When a phone is asleep, the CPU throttles down significantly.  Wakelocks cause the CPU to run up and the phone to come out of deep sleep.  The latest battery optimization in android pie gives the user control over what can be allowed to run in the background and thus control over wakelocks.  

With respect to battery saving apps, they are built on the right concepts.  Their problem is efficacy.  They consume just as much power controlling other apps from wakelocks.  These apps replace one wakelock with another.  It stands to reason as wakelock control is a system level activity that can't be done efficiently at the app level. 

Android pie battery optimization does work extremely well.  I find it to add a couple of hours worth of screen time to each charge cycle.  

[popping]

Program/app allocates memory when needed and deallocates memory when it is no longer needed. 

When an app is killed forcefully without allowing it to gracefully releasing all allocated memory, over time, those memory will grow.  Your phone will slow down as your phone has less memory to work with.  Then, you need to restart your phone to recover those memory.