Classroom slides processor scheduling

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Classroom slides processor scheduling
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• It takes me 10 minutes to walk to TSRB from COC.
  I can run twice as fast as I walk. If I walk
  half the distance and run the remaining half, how
  much time will I take to reach TSRB from COC
• 10 mins
• 5 mins
• 7.5 mins
• 2.5 mins
• Huh? how does this relate to CS 2200?

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Problem spec
Libraries
Partial binary
Human
Algorithm
Linker
Editor
C Code
Executable binary
Compiler
Loader
Memory Footprint
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PCB

• enum state_type new, ready, running,
  waiting, halted
• typedef struct control_block_type
• enum state_type state
• address PC
• int reg_fileNUMREGS
• struct control_block next_pcb
• int priority
• address memory_footprint
• .
• .
• control_block

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Ready queue

PCB1
PCB2
PCBn
I/O queue

PCB1
PCB2
PCBn
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Metrics
Throughput? Avg. Turnaround Time? Avg. Wait
Time? Response time?
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FCFS
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SJF
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Priority Scheduler
ready_q

PCB1
PCB2
PCBn
Level L

PCB1
PCB2
PCBn
Level L-1
. . .

PCB1
PCB2
PCBn
Level 1
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Round Robin
q
Program 1
Program 2
q
Processor
. . .
Round robin scheduler
q
Program n
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Scheduler get head of ready queue set
timer dispatch Timer interrupt handler save
context in PCB upcall to scheduler I/O
request trap save context in PCB move PCB to
I/O queue upcall to scheduler I/O completion
interrupt handler save context in PCB move
PCB of I/O completed process to ready queue
upcall to scheduler Process termination trap
handler Free PCB upcall to scheduler
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Multi-Level Scheduler