This is part of the G1 command line parameter changes enumerated in 6928059.
For some features of G1 we would like to use the same parameters that CMS also uses. Unfortunately, they contain "CMS" in their name. We are going to rename the CMS parameters to something more generic, but create aliases with the old names to retain backwards compatibility.
These are the two changes:
G1MarkStackSize -> rename to MarkStackSize (and make CMSMarkStackSize an alias of MarkStackSize)
ParallelMarkingThreads -> rename ConcGCThreads (and make ParallelCMSThreads an alias of ConcGCThreads)