On Fri, Jan 08, 2010 at 07:37:40AM +0900, Kurt Stephens wrote: > I'm not convinced that the GC is the issue, but I haven't really been > measuring it in production environments. I think common code or Ruby > semantics that create avoidable garbage is the issue and would be an issue > regardless of GC technology, including reference counting. Avoiding garbage doesn't solve the problem; if there is a large number of reachable objects, the mark phase can still take a long time. This is why a number of people want a generational collector, because it can reduce the amount of time spent marking objects. IMO it's clear that there is no one-size-fits all option. I wonder how difficult it would be to make the GC pluggable, so alternate GC's could be provided as gems? (obviously there would still be limitations on these GC's; an incremental collector would probably be out of the question). Paul