<style> .reveal .slides { text-align: left; } </style> ## Project 2 - System Call & CPU Scheduling --- ### Part 1 - System call --- ### System Call (Cont.) 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 in ExceptionHandler * Note the use of `kernel->alarm->WaitUntil()` --- ### System Call (Cont.) * Alarm - software alarm clock, that generates an interrupt every X time ticks * `threads/alarm.h` * The **WaitUntil()** will be called when a thread going to sleep. * Call the **CallBack()** to check which thread should wake up. * See the comments in the file, they are helpful. * Don’t forget the useful data structure like list in the **lib** folder. --- ### System Call (Cont.) * Write your own **test code** like test1 and test2 * Create `test.c` in `test/` * Modify the Makefile in `test/` * Compile in the same way as test1 and test2 --- ### Part 2 - CPU Scheduling RR, FCFS, SJF, Priority --- ### CPU Scheduling Choose **at least one** of the following to implement (The extra implementation will be considered as BONUS) : * First-Come-First-Service (FCFS) * Shortest-Job-First (SJF) * Priority Design your own test code : * Modify `Thread::SelfTest()` or create your method for testing. --- ### CPU Scheduling (Cont.) Design **at least 2** test cases to proof your result * Specify your algorithm in the report. * Specify the test case setting and output in your report. * Design the NachOS interface to switch different scheduling algorithm * `threads/main.cc` --- ### Reference * [The University of Chicago - Com Sci 230 System Calls and Other Exceptions](https://people.cs.uchicago.edu/~odonnell/OData/Courses/CS230/NACHOS/code-syscall.html) * [Purdue University - CS 354 Thread Scheduling and Sleeping](https://web.ics.purdue.edu/~cs354/labs/lab3/) --- ### Report & Policy Report contents, grading policy, late policy --- ### Report 1. **Motivation** * Motivation and the problem analysis * What’s your plan to deal with the problem 2. **Implementation** * How do you implement to solve the problem in Nachos * You can including some (not all) important code segments and comments 3. **Result** * Experiment result and some discussion * Extra effort or observation --- ### Grading Policy * Nachos source code: (40%) * Report: (40%) * Correct format: (20%) * <span style="color: red;">No plagiarism</span> --- ### Late Policy * 10% penalty per day * After 7 days, you will get 70% penalty, but no more penalty after that. --- ### Submission --- Create a folder for the source code and report ``` {Student ID}_Nachos2/ |_ nachos-4.0/ |_ report.pdf // Name the folder w/o curly braces, e.g. r07943154_Nachos2 ``` Compress ```shell= tar -zcvf {Student ID}_Nachos2.tar.gz ./{Student ID}_Nachos2 ``` > **Your source code and report should be handed out by Ceiba** --- ###### tags: `Fall 2020 OS`