Not sure whether this is any good with respect to real-time audio.
"LatencyTOP is a Linux tool for software developers (both kernel and
userspace), aimed at identifying where system latency occurs, and what
kind of operation/action is causing the latency to happen. By identifying
this, developers can then change the code to avoid the worst latency
hiccups."
<http://www.latencytop.org/>
It's part of Intel's OSS initiative:
<http://oss.intel.com/>