In a wholly uninformed and speculative way, I wonder about this . . .
That is, I have no idea how to count user-exit calls, but ...
If a user-exit is in SYSTEM mode, would it swap from TCB to PRB mode?
And anyway, wouldn't the ADSO volume of swaps swamp a user-exit?
We use Exits 2, 21, 20, 22, but all of them only in specialized
situations, not-for-every-task, but fairly often ... and what about the
Exit 17 & 18 stubs? Would those cause a swap everytime? What about
Database Procedures, too?
It's a poser, alright.