Interrupt dispatcher cycles consumption?

Hello all,

currently we are porting project which has been developed with visual dsp to a 2156x based platform. Beside our main isr which is used for audio handling we are using a concurrent isr to do some small work during the audio stuff based on a external event. After I have enabled irq nesting and changed the irq prioritoies the application seems to work. The only thing is now that the amount of consumed cpu cycles seems to be a bit high. Can someone provide the expected amount of cycles which will be consumend by the irq dispatcher (for normal irqs and nested)? And is there a way to speedup the dispatching - unfortunately the fast interrupt dispatchers are not available in cces.

best regards,

flo