Task killer apps " THE TRUTH"


  1. Zerophi

    Zerophi Member


    See 2 posts above, that app should be uninstalled from you phone because it's improperly using CPU time on your phone.
  2. baddriver

    baddriver Well-Known Member

    because that piece of crap app froze and locked up your cpu? sounds like the apps fault
  3. SharonW

    SharonW Well-Known Member

    Okay, I get that, but without a task manager app will you know just from services alone which app is sucking up your memory? It seems to me that would be the sole good reason to have it.

    Also, it appears there are two different conversations going that mix and mingle and get all jangled up in this thread. The first is that some people believe that having too many apps kills the battery quickly and others who feel that too many apps sucks up too much memory and makes the phone sluggish.

    From everything I've seen and read, it does not appear that any apps really affect battery life to any great extent, unless perhaps you've got a buggy one. At the same time that buggy one will also affect your memory management.

    Perhaps, people also think they're gaining battery life by killing tasks when in actuality, because these are new phones, it's been the draining and recharging of their batteries that has increased the battery life.

    Three truths seem to hold for battery life. That beautiful, beautiful screen sucks up the most from your battery. Learn to tone it down when you can. Second, your battery needs to be fully discharged and fully recharged at least once to gain its maximum life. And, lastly, you can get a buggy phone that doesn't respond to either of those two situations, but that's the key. You need to see its response to the first two.

    Ah wait, there's one more battery drainer possibility, but with Verizon's great coverage it seems to be far, far less of an issue. Any time your phone or any cell phone can't find service, it will rapidly drain your battery looking for it as well as heat up your phone to hot, hot, hot.

    In a world dominated by PCs, it's no wonder that the majority assume that background apps are using up too much memory, but this ain't your grandfather's Windows, is it? ;)
  4. rsbenedict

    rsbenedict Well-Known Member

    How can you tell in task manager which apps are sucking cpu? Maybe I'm blind or dumb (I'm not usually, but in this case maybe! LOL), but I couldn't figure it out. :(

    I can see it tells me how much cpu is being used, but I don't see where I can see which app(s) are using it as the only list I see is alphabetical.
  5. tpriddy

    tpriddy Well-Known Member

    GNU's procps/top is an incredibly full-featured, indespensible system monitoring package in the Linux world.

    One of the capabilities of top is to send a signal to a process. Send signal 1 and, if the program was written to cooperate, it will re-initialize itself. Send signal 15 and you're asking an app to clean-up and exit. Signal 9 is intercepted by the kernel and a process exit is "forced."

    All of those task list/manage/kill apps are derivitive of that original top application.

    Stopping a process (signal 15) is usually harmless, at worst leaving behind temporary files or failing to save its persistent state/configuration. But forcing a process to close (signal 9) should be a last resort, used only after you're certain that waiting is hopeless. It usually just "kills" the process with no ill-effects, but sometimes it will create a "zombie" which can make it impossible to fully restart the app until the OS is restarted.

    A zombie's inablility to die may impede an app's ability to restart, properly control itself or communicate with its sister processes. More commonly the process header, the IO data structures, device hardware and/or interprocess communication "protocols" can become deadlocked, wasting system resources (kernel data structures, memory, VM). In some cases this "corruption" can result in runaway processes or an anomolous SW/HW state that could drain the battery at an accellerated rate. In all cases these problems can be cleaned-up by a reboot.
    Android Market has a free application named "top" that was no-doubt inspired by its big brother. It though is a simple process list sorted by the CPU% column. Its other columns may give you a hint at the resources allocated to the dormant processes no longer being used. Those resources are saving the exact state of the application. It makes the app available more quickly as it's already initialized/running.

    SO a dormant process is not using CPU time, and the fact that it is using memory (real or virtual) is not a hinderance to overall performance because the kernel and its system processes know how to reduce most of the footprint of the dormant processes when resources run short.

    So if the OS can reduce the real-memory footprint of dormant apps, what's the benefit to killing them? Just as the amount of RAM (real-memory) on the device is finite, so too is the swap file space (virtual-memory) and kernel data structures (process slots, open files, IO buffers). If your swap file is full you would get an "out of memory" message and applications will fail or refuse to start. Also, anytime any of the system resources is nearly exhausted the allocation of that resource is slower and will kick-in "garbage colection" routines more often.

    But still the user does not need to kill the process. The Android OS will kill the older, dormant processes as necessary to recover system resources as needed.

    Normally in Linux, if you get "out of memory" failures you may want to kill some processes. In Android we should not get "out of memory." If you do, the "Home" or the OS "ROM" is buggy. If you get "out of memory" or "Force close" prompts or recognize a pattern of poor performance, you may be able to figure out an app to avoid. And then there's always my favorite system management saw, "when in doubt reboot."

    BTW, Windows does this all virtually identically to Linux. Android though has some additional magic to remember the state of an application so it may be restarted right where it was in case it needed to be stopped to reclaim resources to allow another app to run.
  6. tpriddy

    tpriddy Well-Known Member

    Use Astro or some other file browser and you can peruse /proc and get all the info there is to get on your processes. Long press on a file, select Open As, Text, File Viewer.

    /proc/<PID>/cmdline is the human readable Linux command line that started the process. /proc/<PID>/status is a list of key: value pairs that you might find interesting.
  7. dbu

    dbu Member

    This all makes so much sense. I deleted my task killer app yesterday and my phone is running better than ever. I have also had my phone off the charger since 7:30am and it is now almost 11:30am and I have used barely any battery with a pretty heavy amount of usage.
  8. djaffinito

    djaffinito Member

    tpriddy, very informative, nice!

    I've never had kill -9 create a zombie personally, I use it on a daily basis.
    preap is good for killing defunct processes, but that's solaris only :(
  9. Maverick9110E

    Maverick9110E New Member

    the point here is it's not just battery life but amount of usage it's taking up on the processor and slowing down certain other tasks.
  10. CRPercodani

    CRPercodani OFWGKTA VIP Member

    Thank you, tpriddy, for explaining this to all the non believers.
  11. tpriddy

    tpriddy Well-Known Member

    Try kill -15 or just kill. It defaults to signal 15. Then up-arrow and re-issue that kill after a short moment. If it was well behaved and cleaned-up and exited, or simply exited, your next kill will get "No such process" as confirmation that it went away. If not, then you can grab the larger hammer and whack it with kill -9.

    If you want to know what a process is doing you can trace its system calls with strace -p <PID>.

    Of course kill and trace only work for the processes owned by your UID... unless you're root.
  12. MichaelGeek

    MichaelGeek Member

    I think you should ignore your Gmail .
  13. MichaelGeek

    MichaelGeek Member

    I am a developer working on Android. So I know a little about how this kind of app works. I am very curious that there are some people said ATK could drain your battery or slow your system. Do you really know how to use it? Shame! Please just give us a proof how it drain your battery. It is only a tool to kill apps running background. Some people say, oh, it's Linux, it don't need to kill apps. I would tell you, if it's an OS, any app consume resources. That's a very very basic term knowledge.
    If you killed all apps and ATK itself, how it consume your battery?
    Don't you know how to ignore some system related apps?
    Don't you know how to close notification?

    You even know nothing about ATK, then you just jump up to say 'oh, it doesn't work'. Are you serious. Or just kidding us.
  14. vincentp

    vincentp Well-Known Member

    I'm not a developer, so I really don't know how exactly it works, but honestly just having the program running and constantly monitoring background processes is a full time job, so it's clearly going to use resources. I don't see the point, really. Most of the programs I end up closing just reopen themselves anyways as background processes, and my battery life is just peachy, so I'm avoiding task killing apps unless I specifically need to stop something.
  15. Fazed

    Fazed Member

    You're correct so far...


    ...and then you dropped the ball. The hardware doesn't only supply power to part of the volatile memory. All of it is powered at all times, because the hardware only knows '0' and '1'. It has no concept of "this memory address isn't being used, and doesn't need to be powered".
  16. zerski78

    zerski78 Member

    I'm probably speaking out of ignorance but... I just set ATK to kill itself as it is killing everything else. When things get sluggish and I run ATK - the device speeds up. I don't see any difference on battery before I installed it vs. afterwards.
  17. MichaelGeek

    MichaelGeek Member

    I agree with you. Any app consume resources. So ATK consume resources too. We don't need to kill apps all the time. We only need to use it to kill some buggy apps.
  18. MichaelGeek

    MichaelGeek Member

    Ya, I don't think any app can save our battery either. What it does is to kill apps. Occasionally if it kills some apps consume battery a lot. That may save our battery.
  19. bubbarob1978

    bubbarob1978 Member

    I am currently doing the same thing....I have ATK set to kill itself after it kills the running apps. Battery life increased a ton once I set it to kill itself. Prior to that I left ATK running in the background all the time and it DID drain my battery more than killing it.

    I am a fan of closing programs even though I know there is a debate as to whether or not you really need to on the Andriod platform. For me its habitual.
  20. CRPercodani

    CRPercodani OFWGKTA VIP Member

    I have merged all these threads about the debate over Task Killer apps. Please post in here and refrain from opening new threads on the same subject.
  21. Jesse

    Jesse Well-Known Member

    Today was my first full work day without ATK installed, and my battery life was much better. Phone came off the charger at 7:30AM. I had a day of heavy use (heavy texting, e-mails, one call, 1+ hour of music, Facebook, browsing, camera, installing apps) and about an hour or two after I got home, I checked my battery status to find it was at 50% at 6:30 or so, which is the best I've gotten out of the Droid yet.

    So I can definitely vouch for the fact that ATK does not help in the slightest bit. Google knows what they're doing; have faith in their software engineers. Let Android do its thing and quit wasting your time with these apps.
  22. MichaelGeek

    MichaelGeek Member

    Don't know why you think ATK should save your battery? It's a tool to kill apps.
  23. Jesse

    Jesse Well-Known Member

    I'm not saying it saved my battery. I'm just saying I didn't even use it today (to kill apps, and in theory, save battery) and I had the best battery life I've seen yet. People seem to think killing open apps will save their battery, when in fact it doesn't matter. Android manages processes and memory just fine by itself.
  24. rawness

    rawness Well-Known Member

    That's a loaded statement that's not necessarily true. For example, there are some apps that when exited (or exited in a certain fashion) still run GPS. Now, sure, you could add an app to turn off GPS, but then you'd have to remember to re-enable it when you open an app that uses. Some people, understandably, don't want to keep a mental tab on their GPS setting.
  25. CookieMomster

    CookieMomster Well-Known Member

    You can also tap the desktop then tap create shortcut then settings and create a shortcut to see usage and to force close a program. I forget which ones they are but they are obvious when you click them.

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