Questions
- The assignment
- Length of answers
- Generell tekst
- Oppgavetekst oppgave 2
- Oppgavetekst oppgave 3
- Oppgavetekst oppgave 4
The assignment
You can download the PDF here: PDF of the theory exam. Dette er lagt ut fordi Inspera gj?r nedlastig sv?rt vanskelig. I tvilstilfeller er det likevel versjonen i Inspera som gjelder.
Length of answers
Question: In the trial exam it was specified that we should write about half a page for each question. There's no suggested length for our answers in this exam, so should we stick with the half a page recommendation?
Answer: The length of answers is a personal issue and there is no strict restriction. It is recommended to write between half a page and one page for answering one of the 8 main questions. Figures or drawings should not be counted.
Generell tekst
Question: What do we do about citations? Where do we refer to the lecture notes? With every single response?
Answer: There is no strict rule. We expect that you use the lecture material. The lecture notes, just like teaching books that you use for a lot of your answers, could go to the start of your document. If you are using a specific paper, white paper or web page to answer a particular question, it is more convenient to add a reference to it before or after that answer.
Question: Should we answer all the points in the assignment text, or should we give one answer that encompasses all the points?
Answer: The bullets exist because the trial exam discussions showed that a more detailed task description would be appreciated by the students. It is OK to answer each assignment as one large question, where your answer addresses all the bullets.
Question: Can I use English words in my Norwegian responses? Can I use English to answer one question and Norwegian for another?
Answer: Yes
Oppgavetekst oppgave 2
There is a sentence: "Hvilke ressurser m? byttes mellom prosesser men ikke for tr?der?"
Question: Does this mean "bytte mellom kj?ring av prosesser" eller "prosesser skal utbytte informasjon seg i mellom"?
Answer: The English text does not have the ambiguity. The assignment is meant to deal with resources that have to be switched ("byttet") when one process/thread is suspended and another becomes active. The assignment does not refer to resources that are exchanged ("utvekslet") between processes/threads.
Oppgavetekst oppgave 3
Question: Should we answer the question "How do you design the scheduler for this operating system?"
Answer: Yes, sorry about the layout that may say otherwise. The important detail is that we do not expect you to invent a new scheduling algorithm, you should design a scheduler. Designing the scheduler means that you should find out which properties it should have (for example: Should it be pre-emptive or non-premptive?), and afterwards choose a scheduling algorithm that has these properties.
Question: "Skal vi svare bare p? punktene eller skal vi ogs? svare p? hvordan vi vil designe en algoritme?"
Answer: We had not anticipated that someone would interpret the statement "Explain for 4 scheduling algorithms how they work ..." to mean 4 scheduling algorithms that you invent. We intend the assignment to mean 4 scheduling algorithms that have been presented in the lecture.
Question: Processes review status updates every second. If a process cannot complete a simulation before receiving a status update, should it complete the previous simulation or does it start over with the new status update?
Answer: You can choose to deal with that problem and how to deal with that problem. When you consider it, take into account that late is better than never for the simulations.
Oppgavetekst oppgave 4
Question: You have a 4 GB address space, is this virtual or physical?
Answer: "Address space" means that every process can potentially address up to 4 GB of memory. The physical / virtual question is an important part of the answer.
Question: The only reason for page table levels is to reduce pages in memory and reduce search time. In theory, we don't even need more than a single level page table as long as we can load the whole page table into main memory. Is there any information missing from the question?
Answer: It must be possible to load and unload the page tables for every process every time it is scheduled in or out. Because of that, it is very typical that every table at every level of the multi-level page-table is page-sized.
Question: Can we assume a size for one entry in the page table or do we have to compute the size of an entry?
Answer: You are supposed to choose a size of entries and argue that it is a good choice. It would be good if you used computations to support your argument. There are many possible correct answers.
Question: What does it mean "Every byte can be addressed"?
Answer: There are operating systems where only every fourth byte can be addressed (0,4,8,12, ...). The bullet is there to prevent people from using such a possibility.