help2002

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help2002

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UWA week 42 (2nd semester, week 12) ↓

2nd project Last accessed time increment? (all 7)

1:20pm Wed 16th Oct, ANONYMOUS

Does time stamp increase when you ignore a page? I have seen some conflicting answers on the forum, and would like to confirm before submitting. For example, if you don't increase time when ignoring a page, output for 0 0 0 0 1 0 0 2 3 1 0 2 3 3 2 would be: 0, 1, 2, 3 4, 7, 99, 99 99, 99, 5, 99 99, 99, 6, 99 0,0,0; 0,0,0; 0,1,1; 0,1,1; 0,2,2; 0,2,2; 0,3,3; 0,3,3; 1,0,4; 1,0,4; 2,2,11; 2,2,11; 3,2,10; 3,2,10; 1,1,7; 1,1,7; whereas if you continue to increase the time stamp, the output would be: 0, 1, 2, 3 4, 7, 99, 99 99, 99, 5, 99 99, 99, 6, 99 0,0,0; 0,0,0; 0,1,1; 0,1,1; 0,2,2; 0,2,2; 0,3,3; 0,3,3; 1,0,4; 1,0,4; 2,2,14; 2,2,14; 3,2,13; 3,2,13; 1,1,9; 1,1,9; is there a single correct solution, or will we be marked based off our assumptions?

2nd project Last accessed time increment? (all 7)

4:35pm Wed 16th Oct, ANONYMOUS

ANONYMOUS wrote:

shouldn't the page table here be: 0 2 4 6 8 14 99 99 10 99 99 99 12 99 99 99 because of each page taking up to spaces in RAM, or am I being dumb?

2nd project Last accessed time increment? (all 7)

4:37pm Wed 16th Oct, ANONYMOUS

I meant this sorry: 0 2 4 6 8 14 99 99 99 99 10 99 99 99 12 99

2nd project Last accessed time increment? (all 7)

7:54pm Wed 16th Oct, ANONYMOUS

You are getting confused with the location in the RAM array and the page frame in the RAM.

Page tables print which page frame the process page is in, NOT the array index the page starts at.

From the project description: "We have a computer whose RAM is an array of size 16. It is an array of pointers. There are 8 page frames in the RAM, each consisting of two contiguous locations in the array. Hence, the page size of this computer is 2. ... Each process has a page table, which is an integer array, entry of a process page table indicates whether the page is in RAM or in the virtual memory (on disc), k if the page is in RAM (k is the frame number, between 0 . . . 7), and 99 if the page is in disc (99 cannot be a frame number). "

2nd project Last accessed time increment? (all 7)

8:03pm Wed 16th Oct, Joshua N.

ANONYMOUS wrote:

> I meant this sorry: > 0 2 4 6 > 8 14 99 99 > 99 99 10 99 > 99 99 12 99

As Anon said this is incorrect. The page table is the slot in RAM the page occupies. A slot is of size 2. So, it should be: 0, 1, 2, 3 4, 7, 99, 99 99, 99, 5, 99 99, 99, 6, 99

2nd project Last accessed time increment? (all 7)

8:06pm Wed 16th Oct, Joshua N.

ANONYMOUS wrote:

> Does time stamp increase when you ignore a page? I have seen some conflicting answers on the forum, and would like to confirm before submitting. > > For example, if you don't increase time when ignoring a page, output for > 0 0 0 0 1 0 0 2 3 1 0 2 3 3 2 > > would be: > > 0, 1, 2, 3 > 4, 7, 99, 99 > 99, 99, 5, 99 > 99, 99, 6, 99 > > > 0,0,0; 0,0,0; 0,1,1; 0,1,1; 0,2,2; 0,2,2; 0,3,3; 0,3,3; 1,0,4; 1,0,4; 2,2,11; 2,2,11; 3,2,10; 3,2,10; 1,1,7; 1,1,7; > > > whereas if you continue to increase the time stamp, the output would be: > > 0, 1, 2, 3 > 4, 7, 99, 99 > 99, 99, 5, 99 > 99, 99, 6, 99 > > > 0,0,0; 0,0,0; 0,1,1; 0,1,1; 0,2,2; 0,2,2; 0,3,3; 0,3,3; 1,0,4; 1,0,4; 2,2,14; 2,2,14; 3,2,13; 3,2,13; 1,1,9; 1,1,9; > > > is there a single correct solution, or will we be marked based off our assumptions?

My other post was incorrect. Don't increase the time stamp when you ignore a page.

2nd project Last accessed time increment? (all 7)

10:34pm Wed 16th Oct, ANONYMOUS

Thank you!