MontaVista Software's latest preemptible kernel patch, preempt-2.4.0-test11-1.patch.bz2, is now available in ftp://ftp.mvista.com/pub/Area51/preemptible_kernel/ Here is an extract from the README file: The patches in this directory, when applied to the corresponding kernel source, will define a new configure option, 'Preemptable Kernel', under the 'Processor type and features' section. When enabled, and the kernel is rebuilt it will be fully preemptable, subject to SMP lock areas (i.e. it uses SMP locking on a UP to control preemptability). The patch can only be enabled for ix86 uniprocessor platforms. (Stay tuned for other platforms and SMP support.) Notes for preempt-2.4.0-test11-1.patch -------------------------------------- - Updated to kernel 2.4.0-test11 Notes for preempt-2.4.0-test10-1.patch -------------------------------------- The main changes between this and previous patches are: - Updated to kernel 2.4.0-test10 - Long held spinlocks changed into mutex locks, currently implemented using semaphores. (We are working on a fast, priority inheriting, binary semaphore implementation of these locks.) The patch gives good results on Benno's Audio-Latency test http://www.gardena.net/benno/linux/audio/, with maximum latencies less than a couple of milliseconds recorded using a 750MHz PIII machine. However, there are still some >10ms non-preemptible paths that are not exercised by this test. The worst non-preemtible paths are now dominated by the big kernel lock, which we hope can be completely eliminated in 2.5 by finer grained locks. (I will be at the Linux Real-Time Workshop in Orlando next week, and may not be able to access my work email address ([EMAIL PROTECTED]), which is why I'm posting this from my personal address.) Nigel Gamble [EMAIL PROTECTED] Mountain View, CA, USA. http://www.nrg.org/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
