patch applied (ghc): Rework the block allocator

[Simon Marlow]

Bulat Ziganshin wrote:
> Hello Simon,
> 
> Thursday, December 14, 2006, 2:35:12 PM, you wrote:
> 
>>  * Rework the block allocator
> 
> 
> Simon, one more feature that i really missing in GHC now is ability to
> *decrease* amount of memory allocated from OS. now, if at some point
> program required 100 megs, it will hold all these 100 megs allocated until
> program finishes and when mmeory goes low, this (unused!) memory will be
> swapped to disk. can this be changed so that after GC memory returned back
> to OS?

Yes.  Maybe after a major GC if we detect that we have a lot more memory 
allocated than was required by the previous GC, then we could release some.  We 
have to be careful to avoid thrashing, so I suggest only doing it after a major 
GC and only when the extra memory exceeds some reasonably large threshold.  I 
don't know how this interacts with Esa's MBlock implementation on Windows.

Would you like to submit a feature request?

Cheers,
	Simon