Hi all, This weekend I've discovered a (serious) kernel scheduling latency issue with the current ieee1394 kernel drivers. Before I submit something about this to lkml, I'd like some more tests. I've been able to reproduce this on two different machines, so I suspect that this is a more general problem. The problem summary is that running ieee1394 ISO traffic can cause scheduling latency spikes up to 1ms, even for RT threads with higher priority. I've written a simple test suite that can be used to reproduce this behavior. The only thing needed is a firewire host controller (no firewire devices). I'd appreciate it if some people would try the test so that I can have an overview of the problem. Of course, this applies mostly to people running an -RT patched kernel. You can find the test suite here: http://freebob.sourceforge.net/old/ieee1394-latencytest.tar.gz see the README for details. Please report the maximum latency you get and the kernel/hardware you're running. Many thanks, Pieter Palmers FreeBoB developer