In JDK 6 b91, we fixed 6200022 to provide a way to use the Linux Posix thread CPU clock. The CPU time implementation is shared by both JVM TI and java.lang.management. The fix was only made to JVM TI but not java.lang.management. We should make the ise of the Linux Posix thread CPU clock for java.lang.management too.
The NetBeans profiler is currently using ThreadMXBean (Java API) to get the CPU time.