Bulat Ziganshin <[email protected]> writes: > now i see what you mean. no, i mean trivial transformation. #650 says > about slow GC. why it's slow? because once you made any update to the > array, the entire array is marked as updated and scanned on next minor > GC (which occurs after every 512 kbytes allocated, afaik). let's > replace big array (say, of 10,000 elements) with array of 100 arrays > of 100 elements each. now, between minor GCs only some of arrays will > be changed and entire amount of memory to be scanned will become less
I actually tried this, and modified Data.HashTable to use a two-tiered chunked dynamic array as you suggest. In some limited testing it was only about 5% faster, so I gave up on it -- you get some GC time back but you also pay a significant indirection penalty by adding an extra cache line miss for every operation. G -- Gregory Collins <[email protected]> _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
