gcc 3.3 garbage collector defaults

[Andi Kleen]

> I have evidence that on one machine, a two-processor machine with
> 128Mb of memory, that GCC starts to thrash when it uses more than
> about 40Mb of memory and two copies are running (this makes sense,
> 2*40Mb of GCC plus about 50Mb for the system = thrashing). This sort
> of thing is why I want to try an adaptive approach.

I don't think the GC defaults have changed. 3.1 also uses 4MB default heap.
The additional slowness comes from something else.

Just the GC looked like a good attack point to fix the general slowdown
regression, as the other slownesses may not be as easily fixable in a 
release tree.

-Andi