1. Dept. of Computer Science – FITA – HUA
Van Hoang Nguyen
Mail: startnewday85@gmail.com
Department of Computer Science – FITA – HUA
Advanced Operating System Course ---------------------------------- Fall 2012
11. Advanced Operating System – Fall 2012
Not work
• TSL instruction is non-trivial in SMPs
Van Hoang Nguyen
12. Advanced Operating System – Fall 2012
• Busy waiting/spin lock
› Cache thrashing
Spinning to wait for a lock is not always a bad idea
Van Hoang Nguyen
13. Advanced Operating System – Fall 2012
• Spinning vs. Switching
› Scheduling critical section may be held
› if critical sections are short spinning may be better than blocking
› static analysis of critical section duration can determine whether to spin
or block
› dynamic analysis can improve performance
Van Hoang Nguyen
14. Advanced Operating System – Fall 2012
• Single processor scheduling
› Which thread should be run next? ---- Time Sharing
•Multiprocessor scheduling
› Which thread should be run next? --- Time Sharing
› Which CPU to run it on? --- Space Sharing
Van Hoang Nguyen
15. Advanced Operating System – Fall 2012
• Time sharing approach
• Space sharing approach
Van Hoang Nguyen
27. Advanced Operating System – Fall 2012
• Sender-initiated distributed heuristic algorithm
Van Hoang Nguyen
28. Advanced Operating System – Fall 2012
• Receiver-initiated distributed heuristic algorithm
Van Hoang Nguyen
29. Advanced Operating System – Fall 2012
Comparing multiprocessors, multicomputers, distributed systems
Item Multiprocessor Multicomputer Distributed system
Node configuration CPU CPU, RAM, IC Complete computer
Node peripherals All shared Shared exc. May be Full set per node
disk
Location Same rack Same room Possibly world wide
Inter-node Shared RAM Dedicated Traditional network
communication interconnect
Operating systems One, shared Multiple, same Possibly all different
File systems One, shared One, shared Each node has own
Administration One organization One organization Many organizations
Van Hoang Nguyen
