Re: Ranting about JVM's default memory limits...

Daniele Futtorovic wrote:


QUOTE:

"Evaluation

It is unlikely that we will eliminate the -Xmx ceiling any time soon.
We get a lot of performance out of having side data structures that
are 1-to-1 with the heap, so we need the heap to be contiguous.

We know how to build "chunked" heaps, but the performance is thought
to be significant (10%?), to allow for a feature that you mostly
won't use if we can size the heap correctly from command line.

This is not high on our list."

ENDQUOTE

This is very bad. I regularly run the incremental garbage collector in
desktop apps because I think it gives far smoother performance. Sun
says the incremental garbage collector also looses about 10% throughput,
but I don't mind a bit. The trade off for me while using the apps is
well worth it.

The idea that Sun knows better than us how we want our apps to run is
just plain silly. I wish they'd get off their high horse and implement
this. Even a 20% loss of through put would probably acceptable.

I especially like the part about "won't use [it] if we can set the heap
correctly from the command line." Hello!? McFly!? Requirements
change! What's a common file size today is trivial tomorrow, and
tomorrow what's impractical today is common. "640k ought to be enough
memory for anyone." Remember that quote? Fix that upper memory limit!
  How long have we been doing that only to have it fail later? Hello?
What does Einstein define insanity as? "Doing the same thing over and
over and expecting a different result?" Hello?

Thanks for those pointers, Daniele. I think I'm going to add my vote to
the first one.