Then, the matching native thread package must be installed at the same location. This package adds some directories to the JDK tree. All the tools in the JDK use green threads as a default. Starting with the 1.1.7 v1a port of the Java Virtual Machine, we have added native thread support. Native threads, on the other hand, use the operating system to do the task switching.
Native threads do have some limitations relative to green threads.
They require more overhead and are limited to the number of processes your Linux kernel supports. Native thread support is new as of 1.1.7 v1a due to the wonderful effort of Phill Edwards. To install the native threads package, you need to first download the JDK, JRE, RT and install that. Next, you need to get the matching native threads package and install that into the same location. Also, at this time there is no native threads support for libc5 systems.