Using a gang scheduler for SMP would allow Forbid/Permit-style disabling of the multitasking to be implemented. Nasty code that uses Forbid to speed things up will have the dubious distinction of being slower though because it will still run on one core only.
Personally, I think the FPGA approach to expanding the Amiga (eg. making slave processors to the master single-threaded CPU) is the best way but SMP is certainly possible.
That´s what I was thinking. Note though, that even the nasty code will have the benefit of the fastest single core Amiga ever. So quit your legacy apps and you have full multicore speed or run them and expect twice the performance impact they would normally have. This is certainly faster than any emulation.
