hello sir ,
as in swapping the data u said u are removing the physical pages 100,200 from 0,1 (technically swapping),and there after u a calling 97 ,83 as physical pages for logical page 1,2 . does this 97,83 holds the same data which earlier 100 ,200 were holding ?
Of course the pages 97 and 83 hold the identical bytes of the original pages 100 and 200. Remember that when the pages 100 and 200 were swapped out, all their bytes were simply written out as data on to sectors of the swap partition. When the pages were to be swapped in, the bytes were simply read into the pages 97 and 83 from the same sectors of the swap partition. As you can see, the process table contains, for each logical page of the process ( for both text and data ), either the number of the actual physical page that contains the bytes OR the number of the sector in the swap partition, with an indication that the data is actually absent in the physical memory. For any access of any byte in a page that is not in the physical memory, MMU automatically generates a Page Absent interrupt whose service automatically locates a free physical page and loads it with the bytes from the swap device.
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