openjdk team mailing list archive

[Andrew Ross <ubuntu@xxxxxxxxxxxxxxxx>]

Package: openjdk-6
Severity: normal


Java uses 1/4 ( MaxRAMFraction [1]) of the _physical_ memory as heap 
(Arguments::set_heap_size() [2]). If there is any limit pushing java 
below this, for example a ulimit, it will fail. The failure could also 
be cause in a virtualised situation for example using OpenVZ where the 
kernel will report the total memory, but the partition has a limit of 
less than 1/4 of that.

The only reasonable workaround is to pass the "-Xmx" option whenever 
you run Java, but this isn't set when installing the 
openjdk-6-jre-headless package, so even setting that package up can 
fail with:

  Could not create the Java virtual machine.
  Error occurred during initialization of VM
  Could not reserve enough space for object heap

I'm not sure of the best course of action to solve this - it seems like 
the nicest thing would be to look at the limit using the ulimit 
interface and reduce the default to a bit less than that (to allow for 
things other than the heap itself).

[1] http://hg.openjdk.java.net/jdk6/jdk6/hotspot/file/8389681cd7b1/src/share/vm/runtime/globals.hpp
[2] http://hg.openjdk.java.net/jdk6/jdk6/hotspot/file/8389681cd7b1/src/share/vm/runtime/arguments.cpp