64-bit java won't allocate more than 2GB of heap memory

Question

I'm running my program from eclipse and using 64-bit java, but I still can't get it to allocate more than 2GB of memory. I'm running some benchmarks so I need a lot of memory.

I have this in my eclipse.ini: -Xmx8g

I want it to use all my memory. Could this be due to a 32-bit version of eclipse? I'm not sure what I have for eclipse.

I've tried sending in -Xmx8g to VMArgs when running the program. I'm running 64-bit windows 7 and a 64-bit JRE.

You are setting the max heap size for Eclipse, not for the program itself. — asteri, Apr 03 '13 at 22:43
How can I run it from the command line while increasing the heap size? — Justin, Apr 03 '13 at 22:44
Have you checked the path to the Java VM in the `eclipse.ini`? By default it points to the 32bit version of Java. Look for the `-vm` tag and see what it's set to. — Martin, Apr 03 '13 at 22:45
What VM are you using? Some of them do have built-in maximums — Daniel Williams, Apr 03 '13 at 23:10

score 6 · Answer 1 · answered Apr 03 '13 at 22:46

6

In the run configuration screen, go to Arguments tab, add -Xmx8g to the VM arguments text box.

answered Apr 03 '13 at 22:46

Pradeep Pati

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I tried this, it still seems to cap at 2GB. System.getProperty("sun.arch.data.model") is returning 64. – Justin Apr 03 '13 at 22:48
You have to create a run config, and run your program from that, then the changes would be effective. – Pradeep Pati Apr 03 '13 at 22:49
Are you filling up the entire 2GB as of now? If not, the JVM may not go to the 8GB level. – Pradeep Pati Apr 03 '13 at 22:53
1

Yup, then getting the exception java.lang.OutOfMemoryError – Justin Apr 03 '13 at 22:54
Also, Runtime.getRuntime().maxMemory() is returning less than 2 GB. – Justin Apr 03 '13 at 23:00

score 2 · Accepted Answer · answered Apr 04 '13 at 12:59

After trying everything else, it looked like VMArguments were simply not working in eclipse.

Changing the DEFAULT VM args within eclipse worked (finally!):

Inserting VM arguments into your JRE: while Eclipse is open, open up Preferences (for Windows: located under Window menu item. for Mac: located under Eclipse menu item), open the Java section, click on Installed JREs, click on the JRE being used (probably will be jre6), click on the Edit... button, and insert this into the Default VM Arguments:

-Xms256M -Xmx8192M

I have the same problem; but I still get this problem and the error is this: `Invalid maximum heap size: -Xmx4096M` `The specified size exceeds the maximum representable size.` — Reihan_amn, Jan 10 '17 at 03:41

score 1 · Answer 3 · answered Apr 03 '13 at 22:42

1

Try doing this:

System.getProperty("sun.arch.data.model")

And see if it returns 32 or 64 inside your program

Also you need to add -Xmx to your launch params for your program not just for eclipse.

You can verify your program's -Xmx is configured properly by doing:

Runtime.getRuntime().maxMemory();

answered Apr 03 '13 at 22:42

Daniel Williams

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Yup, it's 64 bit. How do I add -Xmx for other programs than eclipse? – Justin Apr 03 '13 at 22:43
It is a command line option. So add it to the `java` command line. If you are launching the programs from Eclipse, you can set the JVM command options from the launcher config; e.g. via the "Run > Run Configurations" Wizard. – Stephen C Apr 03 '13 at 22:50

Sergei Krivonos · Answer 4 · 2022-08-28T16:01:35.863

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Try adding -d64 option to theeclipse.ini

edited Aug 28 '22 at 16:01

answered Jul 02 '14 at 17:35

Sergei Krivonos

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64-bit java won't allocate more than 2GB of heap memory

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