Week7 Flashcards
What’s a dirtybit?
A bit in a page that say whether or not that page has been modified
What is the FIFO replacement algorithm?
First in first out, Page that is replaced is the oldest page
What is the LRU algorithm?
Past behaviour predicts future behaviour. In essence, the page referenced longest ago gets replaced
What is the optimal algorithm?
Knock out the page that will not be referenced for the longest period of time
What is global vs local Frame allocation?
Local: A frame is picked that is already owned by the process. Therefore, there is a set amount of frames to pick from
Global: A frame can be from another process. Dynamic!
What is Thrashing
When the CPU is always paging (swapping pages), resource intensive.
If page fault rate is too small….
Then take frames away
What’s a segment
A logical address space to store parts of a program (code, stack, libraries). Is eventually transferred to a physical address through the MCU
How does the segmentation process work? (hint, CPU to…)
CPU (in logical address) -> MCU -> Ram (physical address)
what does * do?
It’s a bash wildcard
what does “quotes” do vs ‘quotes’
”” or {} is evaluated, ‘’ is not
How do you do a bash variable
destDir=/home/student/trd/lab4/dest then to call: echo $destDir
______ is by default a read only file connected to the terminal window
stdin
How do you write an if statement in bash?
if test command ; then true commands elif another test command ; then otherwise true commands else false commands fi
How do you write an while statement in bash
while (( i < 10)) ; do
echo $i (( i++ ))
done
