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The Page-Fault Weird Machine: Lessons in Instruction-less Computation

In case one instruction is one too many for you. A compiler which executes instructionless code through triggering pagefaults.

This is a proof by construction that the Intel MMU's fault handling mechanism is Turing complete. We have constructed an assembler that translates 'Move, Branch if Zero, Decrement' instructions to C source that sets up various processor control tables. After this code has executed, the CPU computes by attempting to fault without ever executing a single instruction. Optionally, the assembler can also generate X86 instructions that will display variables in the VGA frame buffer and will cause control to be transferred between the native (display) instructions and 'weird machine' trap instructions.

When are Actors appropriate?

So there have been conversations about what is appropriate talk on LtU. Personally I am not offended by brusque commentary. On the other hand, while I respect Hewitt, I do think that the 'actors everywhere' thing has not gotten any better, only worse. I posted about process calculi and the first post was to railroad it towards actors, and sure enough enough people took the bait. :-(

I believe that conversations should be allowed to go off on to tangents e.g. talking about quantum. We all have subjective opinions like Justice Stewart about when it has gone from respectable tangent over into frankly trolling beavhiour, even if the troller doesn't do it to be a troll.

I'm asking everybody who is getting involved in each and every actor thread to please stop when they are on topics that did not in fact start out talking about actors. Personally I think it is OK if you go and start a new parallel topic where you draw the link and leave the conversation there. I do not need anybody to stop talking, I just would very much appreciate it if we could all try to see if we can keep the torrent of actor threads contained in their own places, so that other threads can live or die on their own.

(At the very least, realize that by forcing a thread to go onto 2 pages you have broken my ability to get to the new posts. Hardy har-har.)

Thanks for your support.