I've got oprofile working sort of with 2.6.15 kernel on a 24Kc processor using just timer interrupts. I only get samples within vmlinux.out though. When I look at top output during the period of time there is definitely some significant user mode time. Before digging too deep into the problem I thought I'd ask to see if this is a known limitation and if everyone is seeing this. Thanks, Kurt Schwemmer