Java Memory Leaks

Still a problem. Tried launching in launcher which gives option to limit memory - completely ignores it.

Been 7 months unable to play Minecraft now ;(

Attached screenshot is about 4 minutes after launch

For reference, laptop is part of the Asus x54c series. Specs in original post.

Please force a crash by pressing F3 + C for 10 seconds while ingame and attach the crash report here.

That issue sounds like a leak in native code (i.e. inside JRE, drivers, LWJGL native parts, ...). When the JRE has been set an upper limit of like 1G, the memory for java-code should not be able to get past that limit, not even when garbage collection is being flunky; all one would get is java's own out of memory -exception.

Leak being in the native code might explain why so few experience it. It might only appear with specific hardware setup and Minecraft just happens to hit the right (or wrong) spot.

If the leak was in Minecraft's java code, [almost] everyone would be experiencing the problems. That is, getting OOM exceptions/crashes, but not the full 8GB used.

Nevertheless, would be nice to nail the reason, if for nothing else than to warn others about the specific hardware setup (or whatever the reason is found to be) somewhere.

I would like to point out that the attached screenshot shows 800+ MB of memory, not 8GB. 863,552KB == 843.3125MB This is quite a bit less than 1GB == 1,048,576Kb.

This is true. You say this crashes your computer?

Tails - I have now attached the crash report. This report was generated just after MC booted up so will not show a huge amount of RAM eaten.

Markku - That's what I'm wondering. Does anyone have a different Java applet I could run so see if it's the same results (if so, obv wouldn't be a MC problem). I can't think of anything else that uses it right now.

CubeTheThird - I can't get it to go over 1.4gb any more (just fluctates above the mark pictured). Considering this picture shows "memory used" in the Minecraft window a completely separate number from the task manager, it's looking likely it's a Java issue and I may need to take it to Oracle.

Thanks for your guys continued support. Much appreciated.

A full error report has been saved to C:\Users\Owner\AppData\Roaming\.minecraft\crash-reports\crash-2013-03-22_15.07.23-client.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash 😞

Because, as it says in your screenshot, a maximum of 900mb can be used, it's possible java has reserved memory should this amount be needed. If that is the case, it's not that surprising to see the actual memory consumption higher than the allocated amount (what with the java virtual machine and garbage collection to handle). That being said, it is still possible excessive memory is being used. If you execute Minecraft, allocating less memory than the normal amount, does this make any difference to the process size?

My bad, Tails. Real Crash report is uploaded now.

Cube, how much memory would you recommend allocating? I've tried 300MB, 400MB and 800MB limits but will completely bypass this limit.

Thanks

Forced crash on Minecraft after 20 seconds or so gameplay.

Jack, as CubeTheThird explained a bit...

The number reported in the Minecrat client is the java's "heap" memory; it contains the allocated java objects (and maybe stacks, too, can't remember), whether still in use or as-of-yet-uncollected "garbage", and memory that has already been requested from the OS, but not in use for the java objects at that moment.

But Java will also need memory for its own internal stuff ("JVM") and for bunch of other things (like auxiliary data structures used for garbage collection); these are allocated outside that "heap", but they still show as being reserved by the java-process (when looked in task manager or such). It will typically also include things reserved by libraries loaded and used by the application (e.g. if some sound/graphics software has its own data structures).

That is why the value reported by operating system will be always higher. It is quite normal for that extra to be few hundred MBs. (I was a bit surprised to see my own results of upto 700MB extra, but since the usage somewhat stabilized there, I don't think it is leaking for me, or if it is, too slowly for me to spot).

If it is a true leak (in the JVM or external piece of software), the value reported by the OS will continue to grow. Such thing can not be fixed by Mojang, though it is always good to try and find the piece of code (or even hardware setup) that is doing it.

Yeah, I'm sure it's a true leak as it doesn't stabilise. It does as I say stop now around 1.5GB - 2GB depending but the performance will be so poor it's unplayable as seen in the screenshots.

Okay, thanks for your help guys. I guess I'll try asking someone at a Java forum or StackExchange - will report back any findings here.

Would be interesting if any other X54c users experience the same problem (hopefully this will now appear high in search rankings) so we know if it's a a specific piece of hardware.

I could also pray Mojang release a C++ port :O

Cheers again

So if you do a clean install of minecraft, no custom texturepack, standing still in a flat world, memory will just run out of control?

Would you mind taking a snapshot of the memory using jvisualvm ? (Just a little program you can point at a java program, attach and get information from it). I'm almost sure the leak is not of the actual VM. This would just leave broken graphic drivers, but as said before, its likely more people would have this problem then.

Also, what good would porting Minecraft to C++ do?

Same problem...I have 3 gb usable ram minecraft uses all of it 😞(((

It might be worthwhile to get a Program such as IOit's SmartRAM to clear up RAM automatically so it keeps Java's memory usage at a minimum.

This is defiantly a memory leak of sorts.