Memory Management
Q21.
Recall that Belady's anomaly is that the pages-fault rate may increase as the number of allocated frames increases. Now consider the following statements: S1: Random page replacement algorithm (where a page chosen at random is replaced) suffers from Belady's anomaly S2: LRU page replacement algorithm suffers from Belady's anomaly Which of the following is CORRECT ?Q23.
Consider a computer system with 40-bit virtual addressing and page size of sixteen kilobytes. If the computer system has a one level page table per process and each page table entry requires 48 bits, then the size of the per-process page table is _________ mega bytes.Q24.
A computer system implements 8 kilobyte pages and a 32-bit physical address space. Each page table entry contains a valid bit, a dirty bit, three permission bits, and the translation. If the maximum size of the page table of a process is 24 megabytes, the length of the virtual address supported by the system is _____ bits.Q26.
A computer system implements a 40-bit virtual address, page size of 8 kilobytes, and a 128-entry translation look-aside buffer (TLB) organized into 32 sets each having four ways. Assume that the TLB tag does not store any process id. The minimum length of the TLB tag in bits is _________.Q27.
Consider a main memory with five page frames and the following sequence of page references: 3, 8, 2, 3, 9, 1, 6, 3, 8, 9, 3, 6, 2, 1, 3. Which one of the following is true with respect to page replacement policies First In First Out (FIFO) and Least Recently Used (LRU)?Q28.
Consider a computer system with ten physical page frames. The system is provided with an accessse quence (a_{1},a_{2},...,a_{20},a_{1},a_{2},...,a_{20}), where each a_{i} is a distinct virtual page number. The difference in the number of page faults between the last-in-first-outpage replacement policy and the optimal page replacement policy is ______.Q29.
If there are 32 segments, each size 1k bytes, then the logical address should haveQ30.
A computer has 16 pages of virtual address space but the size of main memory is only four frames. Initially the memory is empty. A program references the virtual pages in the order 0, 2, 4, 5, 2, 4, 3, 11, 2, 10. How many page faults occur if LRU page replacement algorithm is used?