On 24/03/2016 11:32, Alex Bligh wrote: >> > Now I'm not saying we >> > need to fully define what it means for a part of the backend to be >> > "dirty" or not. It's okay to leave part of the meaning in the dark, >> > leaving that implementation-defined. > Well, the 3 possible states are: > > * unallocated > * zero > * non-zero > > So the possible replies are a bitfield of those, with a '1' if it 'might' > be in that state, i.e. > > 111 = no idea > 110 = might be zero or unallocated, but isn't zero > 011 = I know it's allocated, but I don't know whether it is zero or not
How do you represent "definitely unallocated?" Paolo > And '000' is not permitted!
