> This I understand in theory; in practice, what, if anything, can an > application writer do to minimize this?
> And what does "SIE" mean? SIE is the Start Interpretative Execution, used by VM to dispatch the virtual machine. The SIE control block is used by SIE micro code to tell which operations will cause an intercept. To some extent the configuration of the virtual machine determines what can be handled by SIE. I don't think application programmers can do a lot in this area. If anything, it would be Linux kernel level work. One of the options in this area is to replace costly virtualisation of part of the architecture by a high level VM-only interface (e.g. ECKD channel programs vs Diagnose I/O). Rob
