•Problems with update
1.What about if the
cache line is several words long?
–Each update to each word in the
line leads to a broadcast
2.What about old data
which other processors are no longer interested
in?
–We’ll keep broadcasting updates
indefinitely…
–Do we really have to broadcast every store?
–It would be nice to know that we
have exclusive access to the cacheline so we don’t
have to broadcast updates…