I would recommend that you apply the Solaris patches and use the native threads version if you can. This new virtual machine is the default virtual machine. You have the option of using either virtual machine, and may want to try both to see which provides the best performance for your application. 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.