Why does hprof=heap=dump have so much overhead?
843829Nov 10 2005 — edited Feb 16 2006I udnerstand why the HPROF option heap=sites incurs a massive performance overhead; it has to intercept every allocation and record the current call stack.
However, I don't understand why the HPROF option heap=dump incurs so much of a performance overhead. Presumably it could do nothing until invoked, and only then trace from the system roots the entire heap.
Can anyone speak to why it doesn't work that way?
- Gordon @ IA