One of the features that you missed the most from IVLE is gradebook, according to the feedback gathered from the anonymous survey. Some students are also having trouble receiving emails sent to @comp.nus.edu.sg accounts.
I have therefore decided to use IVLE gradebook for posting comments and marks for your labs from now on. Lab 3 and 4 have been posted. Lab 5 and midterm scores are coming.
Here is your Lab 7.
Lab 7 is a graded exercise. You have two weeks to complete. Submit your solution to the IVLE workbin before Sunday, 30 October 2011, 10:00pm.
17 October – 21 October 2011
Here are the questions for discussion during Tutorial 7.
Despite a tiny setback, I managed to regraded your Lab 4. Grades have been sent to your SoC email account (with @comp.nus.edu.sg address) which you can read by logging into sunfire and run mutt or pine, or by logging into SoC webmail.
One more common error emerges from this regrading. I noticed many of you call either wait() or waitpid() without specifying the PID of the process you are waiting for (in the case of foreground process). This can cause a problem, as any of the previously running background process can interrupt the wait.
Dennis Ritchie is a pioneer that changed the field of computing. Without him, CS (and CS2106) might have been very different.
1. On Windows, launch Task Manager. Under the Process tab, observe the amount of memory used by the processes. You can go to “View” and “Select Columns”. There are many different columns that corresponds to different accounting of memory usage. What are they? Can you identify some processes that hog the memory in your system?
2. On Linux or Mac, run top. Similarly, you can display various information related to memory usage of processes on your system. What are they? Can you identify some processes that hog the memory in your system?
14 October, 2011
This lecture is the first of a two-part series looking into memory management issues in OS.
Having a hardcopy of slides during lecture would be helpful. Be prepare to take notes during lecture.
Download Slides: PDF
Reading:
Related Wikipedia entries are listed below. These are for students who are keen to go beyond what is covered in CS2106. Read the articles with a critical mind since Wikipedia is editable by anyone.
There is no office hour next week (the week of 10/10/11) for both Chengfang and Wei Tsang.
Here is the midterm paper. We will discuss the solutions next week during the tutorial sessions.
I am making an exception and made a sample solution to Lab 4 available.
We have discovered errors with the grades and marks given out to Lab 4. This means that the email you received may contain incorrect marks and comments. IMPORTANT: if you receive a full marks, you should still check your solution against the sample posted — because your solution could still be wrong or incomplete.
I apologize for the errors, and I am regrading all of your Lab 4 submissions to make this right.
There is no specific question about shell and Lab 4 in the midterm, in case you are wondering. But you should still get familiarize with the system calls involved, including fork, wait, exec, exit, signal, and kill.