Plan 9's default is not to cache, making a "don't cache this" bit unnecessary. If the user explicitly requests caching (by using cfs, say), then he's responsible for making sure it is appropriate.
If I tell the computer to cache /net, that's not the computer's problem, any more than if I bind /proc /net. Since there's no coherence protocol anyway, caching can't be done automatically. It might give the right answer most of the time, but it will screw up corner cases and make the system more fragile. This whole synthetic vs not mentality is Unix brain-damange. On Plan 9 there is no distinction. Everything is synthetic (or everything is not, depending on your point of view). Russ
