Determining Number of Pages Transferred Between Disk and Main Memory

[RyanV]

Hi,

I have a problem on the homework for my algorithms class that involves determining
how many pages are transferred between disk and main memory in an operation on
a two dimensional array.

The LRU method is the replacement strategy in this problem. We are to assume that
each page contains 1024 words. The array is a 2 dimensional 4096 x 4096 array.
Each array element takes up one word.

Here is the algorithm that we are analyzing.

for I := 1 to 4096 do
      for J := 1 to 4096 do
            { A[I, J] := A[I, J] * B[I, J];
              B[I,J] := C[N - I + 1, J] *A[I, J]; }

My question is this: if I am accessing, for example element A[2, 3] does the
entire row 2 get loaded into memory? ie, do all 4 pages of row 2 get loaded.
Or does just the first page of row 2 get loaded since it is the page that
contains element 3.

Thanks

[Athar]

If we're talking about classical paging, only the first page is loaded.