> and, stuff that tickles hardware. Refer to the old crazy stuff bsd did > in the early 80s to get around those issues and still optimize drivers. > Now, wonder if that script could even be found at this point. > > I think I missed the part of the discussion that explains how to do > mmap'ed I/O without volatile, and a good idea of how to tweak the > compiler, such that: > > while (x->statux & BUSY) > ; > > works. If the answer is "don't optimize that functions, you idiot!" I'm > actually ok with that.
On Plan 9, the compiler does not cache the results of explicit memory reads like x->status. So this is not a problem. Russ
