Nov 24

Any questions about anything?

current business

Shell lab is due today.

• Discussed the setup in our last class.
• Reminder that this video can get you started.
• CMU's recitation 10 has some help with the shell lab, including code for sigsuspend (correct way to wait while reaping children)

Unless you're doing this for a writeup, following along with the video, implementing that code, and explaining what the first few traces need, and discussing what else should happen (foreground, background, reaping) is enough.

new business

I've posted HW6, on virtual memory, due the Tuesday after break. You don't need to do sections 9.6 and 9.7, which covers all the details of the the virtual memory addressing its various caching schemes.

You will need to look at the descriptions of malloc and its possible memory allocation algorithms; that's what the next-to-last lab will be on. I'll go over that stuff in next Tuesday's class.

My plan for today is to introduce the virtual memory concepts, the material in 9.1 - 9.5 of the textbook, which is in these two sets of slides, on Virtual Memory Concepts and Systems.

aside

• The birth of unix - interview with Brian Kernighan (the "K" in "K&R") | hackernews discussion

 "I found it easier to program when I was trying to figure out the
  logic for myself rather than trying to figure out where in the
  infinite stack of documentation was the function I needed. So for
  me, programming is more like creating something rather than looking
  it up, and too much of today’s programming is more like looking it up."
  - Brian Kernighan