The VM Options `-XX:AdjustConcurrency` and `-XX:PrintJVMWarnings` are removed from JDK 9. The VM option `-XX:AdjustConcurrency` was only needed on Solaris 8/9 (when using the T1 threading library). The VM option `-XX:PrintJVMWarnings` was a development option only used by unimplemented VM functions that have themselves been removed in JDK 9.