I have investigated what is running when the memory leak starts to get a hold and charted its progress in an effort to find the problem. I do not run Time Machine which potentially causes memory leak problems so that avenue is closed down.
This morning I opened the MacBook Pro, running OS X 10.7.5 with 2.4 GHz i5 and 8 GB of RAM, ran Safari, logged onto the WiFi network, opened Mail and the iTunes. After picking up my mail I refreshed my podcasts which completed successfully. I then noted that performance decreased rapidly and so checked what processes were running and then the Console to check for any errors.
State of the machine from Activity Monitor, the top two processes:
SystemUIServer Memory 5.3 GB CPU 20%-50%
Kernel_task Memory 0.5 GB CPU 20%
Memory usage as follows:
Free: 7.0 MB
Wired: 1.2 GB
Active: 4.5 GB
Inactive: 2.3 GB
Used: 7.99 GB
Vitual memeory used: 184 GB
Swap used: 23 GB
Page ins: 0.6 GB
Page outs: 17 GB
Disc read and write is continuous and 30 GB of disc space has been used in 15 minutes for the VM
Now from the Console I tracked the following:
22/08/2013 11:40:10.420 [0x0-0x45045].com.apple.iTunes: 2013-08-22 11:40:10.419 The plugin 'Quartz Composer Visualizer' failed to load because it has the wrong CPU architecture for this version of iTunes. (3585)
And from that point macx_swapcm and ps_select_segment are active, Emergency paging is switched on, failure to recover emergency paging and the machine is unusable.
The problem seems to lie with iTunes, as I have long expected, though no perhaps Flash player has a part in it when it is running.
I would not expect an OS to allow an Application to run, use all available RAM and then start swapping out to use the hard disc whilst failing to free Inactive memory.
Does Apple have any comments?
You could try uninstalling iTunes by following these instructions: https://discussions.apple.com/message/20625974#20625974
Then see if the unresponsiveness problem still occurs. Indeed, as has been pointed out elsewhere (and possibly here), a low amount of free RAM isn't a problem in Mac OS X as long as the machine is responsive, due to the system's use of inactive RAM when required. If the unresponsiveness still occurs, then it's not iTunes causing the problem. If it doesn't occur, you can try download a fresh install of iTunes from here: http://www.apple.com/uk/itunes/download/
Did you also try running iTunes while in Safe Mode? What happens?
If it still doesn't work after reinstalling I'm not sure I can help.
By the way, re your comment about Apple, this thread might help point you in the right direction.
From the data that I supplied that it can be seen that the OS keeps grabbing available RAM and then it does not use inactive RAM but rather uses the hard disc for virtual memory. This suggests an OS problem since an efficient operating system would swap out 'inactive' memory to the disc and replace this with the memory required by the current working resource.
The common factor in all of my memory leaks has been that iTunes has been started, podcasts downloaded and then iTunes closed. It would appear that as part of the iTunes closedown that a degree of iTunes database maintenance is completed and this could be the potential problem. But to confirm that an iTunes developer would need to comment.
In the past I have found that the OS has managed to grab nearly all of the disc space, the problem only surfacing when you try to swap to another application and response times are infinite. The only option then is a 'hard' rather than 'soft' reboot since closedown would prabably take a week or so. This also often leads to loss of data within open applications.
I don't know why many people keep saying that "inactive memory" is just normal. I also notice terrible slowdown after running some routine applications, such as chrome, keynote, etc, especially after some "sleep". I am sure that it's not a hardware problem, as after a reboot, everything runs so smoothly. Mountain lion should be carefully examined to identify some careless memory management design.
I quite agree with your comments. There is a lack of understanding as to how memory is used within a computer and its operating system. As for virtual memory, well it is not enderstood at all. From my viewpoint the alarming speed with which the OS uses disc space for memory is very worrying indeed for applcation and battery performance.
Hibernation does seem to be a major problem deepnding on the applications being exected when hibernation starts.
This is a design problem within the OS that will, I hope, be addressed within the latest release of Mavericks. As an aside, from the pre-releae hype for Mavericks, Apple are addressing a number of known (well to them) memory problems.
So for me it is teach myself Cocoa, XCode, remember some UNIX and start to delve into the OS. Perhaps I should enlist the help of the Devil's Advocate?
All right. Inactive memory is not important. How do you explain the fact that so many people observe an obvious correlation between the increase of inactive memory and dramatically degraded performance? It's a design defect. Apple engineerers, please admit it and do something. We love MAC and we sincerely hope such serious problems can be solved timely.
All right. Inactive memory is not important. How do you explain the fact that so many people observe an obvious correlation between the increase of inactive memory and dramatically degraded performance?
How do you explain the millions who do not?
It's a problem on your system, not OSX generally, when you accept that and start looking for the cause rather than assuming that it is a general problem that millions haven't noticed yet you may get somewhere!
Your way to address technical problems is fundamentally wrong. Say you developped a software, and millions of people use it. A tiny portion of users, say 5%, reported the software freezes their computer from time to time. Do you look into your software to check whether its design has problems or you blame the 5% by saying that the other 95% didn't complain at all? By the way, I have several friends, who encountered the same problem. But they don't want to waste their time by posting it on Apple forum or somewhere else. So the seemingly 5% can be actually 20% or more.
What programs do you usually run on your mac?
If it's a web browser, mail, skype and itunes, I don't wonder you haven't notice any performance change.
But if you run something more serious like Xcode, AutoCAD and Photoshop, you will notice the performance drop very quickly.