On Wed, Oct 27, 2010 at 23:09, Andrew Coppin <andrewcop...@btinternet.com> wrote: > On 27/10/2010 05:00 PM, John Lato wrote: >> >> I am somewhat surprised that all capabilities must be ready for GC; I >> thought with the parallel GC that wouldn't be necessary. But I don't know >> much about GC implementations so I try not to let their behavior surprise me >> too much. > > GHC has a _parallel_ GC implementation, meaning that the GC event runs in > parallel on several cores. But it does not (yet) have _concurrent_ GC, > meaning that a GC event can happen at the same time as Haskell threads are > running. (Basically, which Haskell code running, the references between > objects could change while the GC engine is trying to analyse them, which > would be Bad.) I understand that the developers are actively working on > fixing this, since it can sometimes have a significant effect on the > performance of multicore programs...
I thought that young generations could be GC'ed while other threads were running, while collecting the old generation required synchronizing all threads. This seems to be what is shown on http://hackage.haskell.org/trac/ghc/blog/new-gc-preview as well. Erik _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
