Lock Bottlenecks
Multiple processors doing Test/Sets on the same lock can cause excessive bus traffic because all trying to access same memory location
Assume Processor Ci owns the lock and lock is dirty
N-1 processors try to do test and set on the lock
- Only one processor will be granted the bus
- Processor Ci will provide shared copy over the bus to the processor that won the bus arbitration
- Will have to provide a copy of the lock to the N-1 processors, will take N-1 bus transactions.