==WARNING== Launching the workload is taking more time than expected

I kept getting the message:
==WARNING== Launching the workload is taking more time than expected. If this continues to hang, terminate the profile and re-try by profiling the range of all related launches using ‘–replay-mode range’. See Kernel Profiling Guide :: Nsight Compute Documentation for more details.

It turns out I was simply impatient, I thought given the message the profiling had hung but after 2.5 hours it reported it had reached 50% and after 4 hours completed the report.

You really should provide some feedback that your application is still operating prior to 2.5 hours!

Thanks for providing the feedback and an update. You should be able to control the overhead by using fewer metrics with the “set” or “section” options. If kernel replay is taking a long time, sometimes application replay can be faster.