no-administration heap?

Colin Walters walters at
Thu Feb 28 14:33:05 UTC 2008


Essentially, my question is: Why do I have to set a maximum heap size
(and PermGen space)?  Practically speaking, it means I have to become
a system administrator for my Eclipse installation (and other JVM
apps).  I kept having it abort, until I tracked it down to it hitting
the maximum heap size and not being able to allocate any more.

It looks like the heuristics are improved in J2SE 5
(, but
it's still a fixed limit.

At least for desktop applications such as Eclipse, what I would like
is a much more user-friendly system where the application uses as much
heap as it needs.  From what I can tell, this is how the Boehm
collector works, which is used by a number of projects like Python,
Mono, etc.  I understand there could be performance impact, but it
makes more sense to me to have a default policy where VM options are a
tuning tweak, not a required change if your application loads a large
file, plugins, etc.

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