10.5 memory leaks?

Posted:
in macOS edited January 2014
Dear all,

I'm a bit phased by this but maybe im missing something obvious...

My MBP (2Gb Ram) is running only safari, terminal and itunes (its been up for a few days now since the last reboot) and both TOP and Activity monitor tell me I only have 50mb physical memory left.... BIZZARO!!!... looking through memory usage for all my listed running processes in both monitoring apps the total sum is nowhere as much as 1.95Gb... so whats up? its like a very large chunk of memory is used by something thats not showing up... even when i'm running as root in bash and run TOP im still missing some 1.5GB

Even when running ps -afxm -o %mem as root all i get shown is some 30% of memory allocated...





On my older G4 PB with 10.4.10 the memory usage listed in TOP seemed to tally up properly... but now in 10.5 (and 10.5.1) this is well weird...

Is this some ultra clever memory management ? or simply a leopard birth defect? it does seem to genuinely be lost for RAM as apps are abviously running slower as they swap memory having to relay on virtual memory... if I reboot my machine and then launch the same apps there's much less memory being used for the same stuff...



Is this Apples implementation of the Universe' Dark Matter (Dark Memory) theory or just a plain dumb obvious bug that slipped their usually tight QA?



Another irritating problem (if less severe) is that Hot corners triggering of the screen saver just plainly wont work with this OS X version....

What do you think oh wise fellow AInsiders?

Comments

  • Reply 1 of 6
    Quote:
    Originally Posted by rashumon View Post


    Dear all,

    I'm a bit phased by this but maybe im missing something obvious...

    My MBP (2Gb Ram) is running only safari, terminal and itunes (its been up for a few days now since the last reboot) and both TOP and Activity monitor tell me I only have 50mb physical memory left.... BIZZARO!!!... looking through memory usage for all my listed running processes in both monitoring apps the total sum is nowhere as much as 1.95Gb... so whats up? its like a very large chunk of memory is used by something thats not showing up... even when i'm running as root in bash and run TOP im still missing some 1.5GB

    Even when running ps -afxm -o %mem as root all i get shown is some 30% of memory allocated...





    On my older G4 PB with 10.4.10 the memory usage listed in TOP seemed to tally up properly... but now in 10.5 (and 10.5.1) this is well weird...

    Is this some ultra clever memory management ? or simply a leopard birth defect? it does seem to genuinely be lost for RAM as apps are abviously running slower as they swap memory having to relay on virtual memory... if I reboot my machine and then launch the same apps there's much less memory being used for the same stuff...



    Is this Apples implementation of the Universe' Dark Matter (Dark Memory) theory or just a plain dumb obvious bug that slipped their usually tight QA?



    Another irritating problem (if less severe) is that Hot corners triggering of the screen saver just plainly wont work with this OS X version....

    What do you think oh wise fellow AInsiders?



    Download MemoryCell: http://www.rogueamoeba.com/freebies/



    It's really handy for checking the memory of a particular application. Safari has a memory leak problem and needs to be restarted every once in a while. MemoryCell will help you know when it's time to reset it. It's an unfortunate problem with an otherwise great browser.
  • Reply 2 of 6
    Quote:
    Originally Posted by Daffy_Duck View Post


    Download MemoryCell: http://www.rogueamoeba.com/freebies/



    It's really handy for checking the memory of a particular application. Safari has a memory leak problem and needs to be restarted every once in a while. MemoryCell will help you know when it's time to reset it. It's an unfortunate problem with an otherwise great browser.



    Humm i doubt this little (cute) app will reveal any more than tools like TOP and PS have... i'm not sure about this Safari memory leak you talk of... if it was the case I would have seen memory allocated to the Safari process mushroom but that has not been the case. at any rate i'm not sure what you are describing can be classed as a memory leak - rather I would class it as browser caching leading to a linear increase in memory usage over time, this is a common problem with web browsers and is more a by-product of a 'feature' than a proper memory leak bug... unless what you describe is a very bizarre memory leak that does not associate the leaking memory with the Safari process... is that the case?



    I did try and restart Safari a few times when seeing this issue but memory was not released... I think this is more like an underlying OS or even driver issue. but i could be wrong...
  • Reply 3 of 6
    Quote:
    Originally Posted by rashumon View Post


    rather I would class it as browser caching leading to a linear increase in memory usage over time



    If that were the case, the memory would be released by using the Empty Cache function but that doesn't do it. Safari 3 is now using 170MB with 2 tabs open. If I reopen it, it uses only about 9 MB. I just found this that answers some questions for me.



    http://discussions.apple.com/thread....29624&tstart=0
  • Reply 4 of 6
    The bit you are failing to understand is that "free memory" is wasted memory. Just because something is sitting there in memory does not mean that the memory is not available for use if a process needs it. It takes just as much time to map memory that is in use (but has not changed from the on-disk data) as it does to map memory that is not in use. So why not just leave data in-memory in case you happen to need it again (very common occurrence).



    MacOS X's memory subsystem is far smarter than you in this area, don't try to out think it, because you can't. Welcome to the world of modern memory management.



    PS... the only place where you might need free memory is because you have an application that is doing something very very time sensitive that needs a single block of memory. And in fairness most of these could do so even with a physically fragmented block. The only apps I have ever heard that are like this are audio apps, and I happen to think it is because the authors don't know how to "wire" memory down (keep it from being paged out).
  • Reply 5 of 6
    This topic has been discussed on these forums ad nauseum. Karl is correct in that all files read from the disk are cached in ram. When apps/files need this ram, the stale caches are flushed to make room for the app/file.



    Essentially, over time, OS X will use as much ram as you have. This makes your computer faster. It is not a bad thing.



    This approach to memory management is common amongst all unixes, linux, etc.
  • Reply 6 of 6
    Quote:
    Originally Posted by Karl Kuehn View Post


    The bit you are failing to understand is that "free memory" is wasted memory. Just because something is sitting there in memory does not mean that the memory is not available for use if a process needs it. It takes just as much time to map memory that is in use (but has not changed from the on-disk data) as it does to map memory that is not in use. So why not just leave data in-memory in case you happen to need it again (very common occurrence).



    MacOS X's memory subsystem is far smarter than you in this area, don't try to out think it, because you can't. Welcome to the world of modern memory management.



    PS... the only place where you might need free memory is because you have an application that is doing something very very time sensitive that needs a single block of memory. And in fairness most of these could do so even with a physically fragmented block. The only apps I have ever heard that are like this are audio apps, and I happen to think it is because the authors don't know how to "wire" memory down (keep it from being paged out).



    As much as i found your tone to suck you are essentially right. Instead of wasting time comparing my (small and useless) brain to the supreme and unfathomable complexity of OS X memory management you could have just explained it properly like they do here:

    http://www.macosxhints.com/article.p...10613140025184



    But anyway thanks for correcting my error, i'm wiser for it...



    Cheers
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