Reason for interrupt in device driver

In my Audio driver I have Interrupt handlers for Download audio i.e., Audio playback and Upload i.e., Audio Record

Sometimes when music is playing smoothly I am getting interrupt because of which i hear pause for very short duration say some ms or glitch

How can I find which thread is overtaking CPU and pausing audio thread. Though Audio thread is having high priority?

I used systrace for profiling my device but i couldn't find the root cause of the problem creating thread