I cannot for the life of me find a definition of what the Java VM flag CMSClassUnloadingEnabled actually does, other than some very fuzzy high-level definitions such as “gets rid of your PermGen problems” (which it doesn’t, btw). I have looked on Sun’s/Oracle’s site, and even the options list doesn’t actually say what it does. … Read more
I thought it would be great to have a comparison between _JAVA_OPTIONS and JAVA_TOOL_OPTIONS. I have been searching a bit for one, but I cannot find anything, so I hope we can find the knowledge here on Stackoverflow. JAVA_OPTS is included for completeness. It is not part of the JVM, but there is a lot … Read more
Specifically, why would it help to fix a PermGen OutOfMemoryError issue? Also, bonus points for an answer that points me to the documentation on JVM arguments… 3 Answers 3
I’m using IDEA 12 Leda on Mountain Lion. I wanted to increase the maximum memory that IDE can use. I set the VMOptions in Info.plist file to be -Xmx2048m -ea -XX:+HeapDumpOnOutOfMemoryError -Xverify:none -Xbootclasspath/a:../lib/boot.jar When I open up IDEA, I still see the maximum memory to be 711m. jps -v shows my VMOptions has been loaded … Read more
First of all, I have a box with 8gb of ram, so I doubt total memory is the issue. This application is running fine on machines with 6gb or less. I am trying to reserve 3GB of space using -Xmx3G under “VM Arguments” in Run Configurations in Eclipse. Every time I try to reserve more … Read more
The permanent space is where the classes, methods, internalized strings, and similar objects used by the VM are stored and never deallocated (hence the name). This Oracle article succinctly presents the working and parameterization of the HotSpot GC and advises you to augment this space if you load many classes (this is typically the case for … Read more
