Garbage collector stopping my world for half a second

Thu Dec 1 18:45:00 GMT 2005

Boehm, Hans writes:
 > Could you remind me what your platform is?
 > 
 > For a modern PC, with a heap size of 8MB, and assuming the root size is
 > reasonable, 60 msecs should be on the high side. (The GC time should be
 > roughly proportional to <live data size> + <root size>. On a GC_Bench
 > variant, the marker seems to scan roughly 200-250MB/sec on a single 2
 > GHz P4 Xeon. There is a bit of other overhead associated with
 > collections, but that's the lion's share.)
 > 
 > Unless you're on a very slow processor, the 360msecs seems anomalous to
 > me. It would be useful to understand what's going on during that time.
 > Presumably paging is not an issue?
 > 
 > More generally, the GC provides some support for incremental collection,
 > but AFAIK that's not really supported by gcj, and hence may take some
 > effort to get to work for your application.
With gcj our root set is way, way too big. Fixing this is at the top
of my list of things to fix.
Andrew.