Hello Daniel, Thanks for looking into it also. Steven already made clear to me that the 'struct semaphore' type on the RT-kernel should not be used as a counting-semaphore, but as some sort of legacy-mutex... (The confusion that this will cause is clear by now...) I still do not understand the problems I had with the interruptible-waits on a real rt-mutex, but I have to figure that out again on Monday. Maybe one confusion let to another... (Note, A completion will not work for me, because they are not designed for reuse across several threads. The read/write runs in user context and as such it can be called by different threads, which would require a init of a completion before waiting on it, but that would be racy, I could miss the awake by the init) > So I converted your code to use a compat_semaphore, and no oops > happens.. Which makes sense because compat_semaphores are designed to > work the way your using them. Actually, IMO, compat_semaphores behave like semaphores should behave, and thus the same as they behave on a non-RT kernel, and at the locations where the semaphores are now misused as mutexes on RT, we should replace them by differently-named-mutex-type-semaphores, or better: real-RT-mutexes.. IMO this wrong usage of semaphores is solved by modifying the code that actually made proper use of the semaphores, and I think that if the naming matches the mainline kernel, we only need to patch the files that really need to be patched during the integration in mainline of the RT-patch. Kind Regards, Remy Bohmer - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
