Naming and Operations: Msg Passing
Direct support at hardware interface
- But match and buffering benefit from more flexibility
Support at sys/user interface or above in software
- Hardware interface provides basic data transport (well suited)
- Send/receive built in sw for flexibility (protection, buffering)
- Choices at user/system interface:
- OS each time: expensive
- OS sets up once/infrequently, then little sw involvement each time
- Or lower interfaces provide SAS, and send/receive built on top with buffers and loads/stores
Need to examine the issues and tradeoffs at every layer
- Frequencies and types of operations, costs