On Thu, 6 Jan 2011, der Mouse wrote: > > No. The existance of ASIDs along with the hardware implementation is > > fundamentally a proprty of the MMU design. Exposing this information > > outside of the MD code base (pmap(9)) breaks encapsulation. > > In detail, yes. In general, no. > > I haven't looked at the ASID issue in detail. But it sounds to me as > though it needs at least a few things elsewhere, though they can (and > probably should) be kept as general as feasible. For example, every > process (or maybe lwp) needs to have an ASID hanging off it - but it > doesn't have to be done that way; I'd say it should be done by giving > each process (lwp) a pointer, or maybe a small block of data, which is > totally private to the pmap in use. If pmap wants a call at process > exit, or syscall exit, or whatever, fine - but do it as a > general-purpose hook which the pmap in use can use to do whatever it > wants, not just ASID fiddling.
In detail no. In general no. I've implemented pmap(9)s that use ASIDs and I never needed this feature. It's all hidden inside pmap(9). All the hooks you should need already exist. Before adding yet another undocumented general requirement I want to know why so I don't get bit in the butt by it when I implent a new pmap(9). This just doesn't sound like some weird general external requirement that needs to become everyone's headache. Eduardo