[LITMUS^RT] tracing time duration within IRQ handler

[Glenn Elliott]

Feather-trace has evolved a little bit since I last did overhead measurements.  Specifically, the counting of IRQs.  The code implies to me that I should be using different trace methods for events measured from within an IRQ handler.  Is this true?

When should I use TIMESTAMP_IRQ() and TIMESTAMP_IN_IRQ() macros for tracing?

Thanks,
Glenn