1. CS533 Concepts of Operating Systems Class 11
User-Level
Remote Procedure Call

2. CS533 - Concepts of Operating Systems
Questions
Where does most of LRPC’s overhead come from?
How can the kernel be eliminated from the call path on SMMPs with user-level threads?
To a thread URPC is synchronous, but to the thread library it is asynchronous … explain.
Why do kernel thread switches have long term cache and TLB effects that user thread switches do not?
CS533 - Concepts of Operating Systems

3. CS533 - Concepts of Operating Systems
Questions
In what ways does URPC do “cooperative scheduling” across address space boundaries?
In what ways does URPC do load balancing?
How does URPC affect throughput and latency?
How can a client’s CPU be hijacked by a server?
How could you solve this problem?
CS533 - Concepts of Operating Systems

4. CS533 - Concepts of Operating Systems
Questions
Now we have scheduling, synchronization, and IPC outside the kernel
What should be in the kernel?
Note, these papers predated scheduler activations
Second half of CS533 examines the evolution of kernel structuring approaches
CS533 - Concepts of Operating Systems