Massive Mountain Lion memory leak

Csound1

I didn't ask you about page outs/ins. I asked Scott Newman.

You have a lot of RAM, thats why your answer is irrelevant. Scott has the same RAM that I have (4GB) and we can compare our systems evenly.

sergibondarenko wrote:

Csound1

I didn't ask you about page outs/ins. I asked Scott Newman.

Actually you asked me (see below, especially the part about in reply to Csound1))

But you probably thought that you aere replying to someone other than me without actually knowing.

That's OK,

I'll leave it up to you.

Csound1

Please do not take offense, I have long understood that I need more RAM and SSD.

I just do not like the fact that the OS X 10.8 requires more memory than Windows 7/8 or Ubuntu 12 to solve same tasks. It's a kind of stupid.

I'm not offended by your error.

sergibondarenko wrote:

Please do not take offense, I have long understood that I need more RAM and SSD.

I just do not like the fact that the OS X 10.8 requires more memory than Windows 7/8 or Ubuntu 12 to solve same tasks. It's a kind of stupid.

I am currently running my data ingest testing on my 8 GB Core 2 Duo 2009 MacBook Pro running Mountain Lion. Normally I use one of my Linux servers that have from 8-64 cores and 32-252GB of RAM. However, I can't use the Linux servers this week because my development server keeps running out of RAM (it has 36 GB) mysteriously and causing Oracle connections to fail. They even rebooted it yesterday to try to clear it up and it is back to 0 GB free.

So don't tell me MacOS X has memory problems that Windows or Linux don't. I don't have memory problems like this on my Mac. Sure it would be faster if it had 32 times the number of cores and 30 times the RAM. Twice this year my Linux machines have been ususable for extended periods even with a full IT stuff and on-site support from Oracle. But it never locks up like Linux. It never has DLL conflicts like Linux. It never needs to be rebooted like Linux.

Got news for you. We run a simple Mac Mini server and was having MAJOR leakage...we only run about 2 -3 light apps. (Server, Dropbox and Dropcopy)

We upped our ram from 4GB to 16 GB.....so even still....after each reboot or purge....in about 10 minutes...the free RAM dwindles down to 18 mb.

So...what are you saying about leaks only happen with people who run Photoshop?

I didn't say anything about "leaks". I said that Photoshop users commonly report problems running with 4 GB of RAM in Lion and Mountain Lion and experienced no such problems in Snow Leopard.

You are running a server and complaining about free RAM. Lack of free RAM does not imply leaks. A server is much different and you don't want any free RAM on a server. A server is supposed to use all of its RAM so it doesn't have to go to disk to serve user requests.

So...we did a thunderbolt raid firmware update...when I rebooted from that update....the FREE RAM started dwindling down again and stopped at around 8GB Free. It stopped dropping and slowly bumped itself back up to 12 GB FREE on it's own. This happened over the span of 30 minutes after rebooting after that update.

I don't know if it was the firmware. There was just wonky stuff going on for a few weeks.

FYI, I had a progressive free memory leak problem which was solved by quitting Safari. Subsequent use without open YouTube tabs resulted in a stable memory as well. It is good to see this vexing problem in the rearview mirror.

Whatever these cleverclots might say, the fact is I just installed Mountain Lion a few weeks ago and I have been having incredible problems with my Mac slowing down to a snails pace (as you say), I'm having to run memory clean and disk doctor approximately 3 or 4 times per 8 hour work session, just to get it running again. Like you I have 8 gbs of ram and I too noticed that when left inactive for any length of time the amount of memory I have available drops right down to just over a gig. This is crazy and I think your initial complaint is correct. MASSIVE MEMORY LEAKS - suffice to say, until apple stop behaving like EA games and get their house in order I WILL NOT BE BUYING THE NEW MacPro when it comes out.

Dunno if this helps, as a developer of Mac os x software, we have recently moved one of our code libraries from snow leopard to mountain lion and have seen free memory decreasing rapidly even though it is released correctly in the code. Code has been profiled a lot with xcode instruments and shows no leaks or increasing usage. Something in OS seems to of changed as we have the different machines running continously next to each other and snow leopard is releasing the memory we have released back to free, mountain lion does not.

Have no fix yet, apart from we will prob modify code to reuse a memory cache to reduce memory allocation/deallocations.

After much testing and benchmarking we have found the problem in our case and probably others as well. Unfortunately our fix is a developer fix not a user one.

We found that some Apple Objective C Class files that use the NSData class for reading files were the cause. The default NSData implementation now seems to cache a files data in memory when it didnt appear to in snow leopard. This cached data isnt released when we release memory obviously as its meant to speed reopening of the same file between app launches.

In testing opening and closing a lot of files after a purge, on 5 Mountain Lion machines we have out of 20 bench tested (same hardware, same software), these 5 would continually lose memory until it ran out. Inactive is never reused, and vital system services start to be killed off due to lack of memory. This can be seen in the logs (killed 9).

The solution for us is to use methods on these Apple classes that allow us to pass NSData objects into them as opposed to letting Apple create their own. The benefit of this is that by creating our own NSData object we have the option (NSDataReadingUncached) to configure it to not cache the files contents in memory. This has now fixed it for us and is backward compatible with snow leopard.

Apologies that this is not a user fixable solution, although 'purge' is a blunt global instrument for users to alleviate the problem for the time being.

Interestingly, Apple have redesigned the memory section of activity monitor to show File Cache as separate from other memory instantly showing the problem as it keeps growing without the change mentioned above. Would of saved us some troubleshooting time if we had tested on Mavericks first as the problem would of been more obvious, as we would not of gone down the path of "Memory Leak" profiling.

I can see why Apple say it works as it should as File Caching of recentl used files is obviously a feature, but the default change is probably going to catch a lot of developers out who use the default behaviour of some Objective C Classes.

See below for developer details:

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation /Classes/NSData_Class/Reference/Reference.html#//apple_ref/c/tdef/NSDataReadingO ptions

No, that is not it. I'm loading audio samples and the amount used in this project is around 15GB. Under Snow Leopard, a certain amount, like 500MB or something of inactive would build up. Now it means that this 15 or so GB template is perilously close to maxing out my 24GB of memory.
You have an assumption behind some theory. "it means it is being used and released" No. It isn't. It's useless memory. In reality, this is a problem.
I'm probably going to have to give up whatever I'm using that requires 10.8 and go back to 10.6.8 if this can't be solved.

"'purge' is a blunt global instrument for users to alleviate the problem for the time being."
Purge isn't working right either here. It purges a little but actually a small percentage of the inactive READ UNUSABLE memory.

"but why are you blaming Apple" - why are you trying with all sorts of tactics to deny someone else's problem?
I know what was happening under Snow Leopard, and now I finally caved to ML and the amount of blue area in Activity Monitor's RAM display is dramatically more for exactly the same situation. I'm not doing one thing differently except for the change of OS.

The OS is NOT giving this RAM up with new loads; after a certain point the OS is beach ball o' doom all the time. So there is purge, which itself does not appear to work as well. But this is a real-life problem, sorry if that upsets you, identifying so strenuously with Apple as it appears here.