> It's that "touching" of all the pages controlled by the GC that ultimately wrecks swap performance. But also the fact that moving collector like to hold onto

> It's that "touching" of all the pages controlled by the GC that ultimately wrecks swap performance. But also the fact that moving collector like to hold onto memory as downsizing is pretty hard to do efficiently. The memory that's now not in use, but still held onto, can be swapped out.