We currently have two stack local mappers, the default and the debug version. The default localmap has some optimizations to reduce the lifetime of objects, whereas the debug local mapper does not do that.

There are cases where it is useful to use the debug mapper in order to rule out certain possiblities when investigating memory leaks or finalization issues. Currently, the only way to enable the debug mapper is to run in debug mode.

This issue proposes to introduce a new option to enable the debug mapper -XX:[+|-]UseDebugLocalMap

The debug mapper is j9localmap_DebugLocalBitsForPC see installDebugLocalMapper.