An Operating Systems Vade Mecum

Paging 89virtual addresspageoffsetframepermissionspresentphysical addressframeaddress-translation tableFigure 3.13 Hardware algorithm for translating page-oriented accessHere is an example of a paging situation with two processes, A and B. We willassume that both are simultaneously using parts of physical store. For simplicity, we willmake virtual addresses two decimal digits, of which the first is the page number and thesecond is the offset. We will also show the contents of a translation look-aside bufferthat holds two entries of the current page table. For this example, we will not let the TLBentries change, even if a cache miss occurs. A is currently running, so entries in thetranslation look-aside buffer refer to it.Page table for process AVirtual page number Page frame0 7 1 8 2 absent 3 4Number of pages = 4