Hi folks, I found out that parallel threads using the Posix skin cause kernel oops somewhere between the finishing of the threads and the main thread. I have two threads, say thread A and thread B. Both created as joinable threads and they have both the same priority 99. The main routine hold a semaphore semA to synchronize the threads. After the creation thread A waits on the Semaphore semA, while the thread B runs and releases semA, so that semA can finish. On exiting the thread B I always get a Kernel ooops. The kernerl says: unable to handle kernel paging request at virtual address 6b6b6b77 etc....... I scratched some simple code which causes this Kernel Ooops. Packed a tar ball together with the makefile and attached the tar ball it to this mail so that you might have a look at it yourself. I'm using Kernel: Vanilla 2.6.12 patched with adeos-linux-2.6.12-i386-r12.patch Distr. Debian 3.1 Testhost: vmware 5.0 compiler gcc 3.3.5 I also wrote some code doing the same tasks in RTAI native context and it ran without problems. Hence I suppose the problem to be in the posix skin. Am I making any mistakes in the code or have I evtl. found a bug in the posix skin? Cheers Luotao Fu