Replacement for GMP: Update

[Simon Marlow]

Bulat Ziganshin wrote:
> Hello skaller,
> 
> Sunday, August 13, 2006, 4:34:14 AM, you wrote:
>
>>But the state of the art is then two stages behind the
>>requirement: Haskell still has to 'world stop' threads
>>to do a major collection.
>  
> is not exactly true. look at "Non-stop Haskell"
> (http://www.haskell.org/~simonmar/papers/nonstop.pdf)
> 
> i don't know why it is not included in 6.6 or previous version

Simply because it adds overhead (both in runtime and code complexity), and the 
benefits are relatively modest.

To comment on another point in this thread: currently the generation 0 GCs 
(minor GCs) also stop-the-world, even on a multiprocessor.  This is a 
significant problem, and we have some ideas for fixing it, but no code yet (it's 
   a possible intern project, if anyone is interested).

Parallel major GC was worked on by Roshan James during his internship here this 
summer, and we have some working code, but it needs a lot more testing and 
tuning, and it may be some time before we can incorporate this into the mainline.

Cheers,
	Simon