Performance values somehow depend on MCUXpresso Debug/Build

[RobertK66]

Since I wrote the 4 performance tests for the ring-buffer, I experienced different results with each build/debug cycle of the software. I slowly increased the accepted times to be used in the test but there are always builds/runs which are out of this accepted test tolerances.

Normal Values of this test:

Push/pop test (char): 8313/29688 us.
Push/pop test (ptr): 8756/32501 us.

This still shows an error because currently the test checks for 8500/30100 and 8900/32400 us.

But now (after experimenting some settings in the debugger config...) I get crazy long values like:
Push/pop test (char): 19754/65939 us.
Push/pop test (ptr): 22889/70940 us.

At this moment I have a image where when I disconnect the debug session, the values change back to normal ones. But this behavior is somehow unpredictable. I do not know now what causes this and whats the dependencies to the MCUXpresso build/debug settings.