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Nachos Project Assignment 2 CPU scheduling

Nachos Project Assignment 2 CPU scheduling. If you still have trouble to install Nachos. https :// code.google.com/p/damody/downloads/detail?name=mips-decstation.linux-xgcc.gz. Part 1-System call. Implement a system call – Sleep() userprog / syscall.h Define a system call number of Sleep

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Nachos Project Assignment 2 CPU scheduling

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  1. Nachos Project Assignment 2CPU scheduling

  2. If you still have trouble to install Nachos • https://code.google.com/p/damody/downloads/detail?name=mips-decstation.linux-xgcc.gz

  3. Part 1-System call • Implement a system call – Sleep() • userprog/syscall.h • Define a system call number of Sleep • test/start.s • Prepare registers for Sleep • userprog/exception.cc • Add a new case for Sleep

  4. System call:start.s • Assembly language assist to make system calls to the Nachos kernel • http://www.mrc.uidaho.edu/mrc/people/jff/digital/MIPSir.html • Take System call Sleep as an example .globl Sleep .ent Sleep PrintInt: addiu $2,$0,SC_Sleep // put system call number in register 2 syscall /* all parameter of this system call will be stored in register4, 5, 6, and 7 by MIPS machine automatically. */ .end PrintInt

  5. Part 2-Non-preemptive shortest job first scheduler • Nachos default scheduler: Round Robin • Shortest job first • n+1 = tn + (1- )n • n time of the nth predicate CPU burst • tntime of the nth actual CPU burst • Design several test case to proof your result • E-mail your code and presentation files(report) to TA

  6. Begin Running Invoke Sleep(x) Per timer interrupt: 1.Record actual CPU burst 2.Wake up time up threads 1.Set next predicted CPU burst 2.Insert this thread to Sleeping thread lists 3.Invoke thread->Sleep Non-preemptive shortest job first scheduler • thread/alarm.cc, thread/alarm.h • Implement WaitUntil(int x) to handle sleep(int t) • Add a class to management the threads which are sleeping

  7. More details • http://puremonkey2010.blogspot.tw/2013/05/nachos-40-nachos-system-call.html

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