Operating Systems · Previous year questions
Memory Management and Virtual Memory
37 questions from GATE CS 2011 to 2026, newest first.
Questions
GATE CS 2026 Set 1, Q.54
Consider a system that has a cache memory unit and a memory management unit (MMU). The address input to the cache memory is a physical address. The MMU has a translation lookasi...
Memory Management and Virtual Memory
GATE CS 2026 Set 2, Q.54
A system has a Translation Lookaside Buffer (TLB) that has a reach of 1 MB. TLB reach is defined as the total amount of physical memory that can be accessed through the TLB entr...
Memory Management and Virtual Memory
GATE CS 2026 Set 2, Q.55
Consider contiguous allocation of physical memory to processes using variable partitioning scheme. Suppose there are 8 holes in the memory of sizes 20 KB, 4 KB, 25 KB, 18 KB, 7...
Memory Management and Virtual Memory
GATE CS 2025 Set 1, Q.14
Consider a demand paging memory management system with 32-bit logical address, 20-bit physical address, and page size of 2048 bytes. Assuming that the memory is byte addressable...
Memory Management and Virtual Memory
GATE CS 2025 Set 1, Q.54
In optimal page replacement algorithm, information about all future page references is available to the operating system (OS). A modification of the optimal page replacement alg...
Memory Management and Virtual Memory
GATE CS 2025 Set 2, Q.47
Consider a demand paging system with three frames, and the following page reference string:
1 2 3 4 5 4 1 6 4 5 1 3 2. The contents of the frames are as follows initially and...Memory Management and Virtual Memory
GATE CS 2025 Set 2, Q.58
A computer system supports a logical address space of bytes. It uses two-level hierarchical paging with a page size of 4096 bytes. A logical address is divided into a…
Memory Management and Virtual Memory
GATE CS 2024 Set 1, Q.62
Consider a memory management system that uses a page size of 2 KB. Assume that both the physical and virtual addresses start from 0. Assume that the pages 0, 1, 2, and 3 are sto...
Memory Management and Virtual Memory
GATE CS 2024 Set 2, Q.24
Which of the following tasks is/are the responsibility/responsibilities of the memory management unit (MMU) in a system with paging-based memory management?
Memory Management and Virtual Memory
GATE CS 2024 Set 2, Q.64
Consider a 32-bit system with 4 KB page size and page table entries of size 4 bytes each. Assume bytes. The OS uses a 2-level page table for memory manage...
Memory Management and Virtual Memory
GATE CS 2023, Q.23
Which one or more of the following options guarantee that a computer system will transition from user mode to kernel mode?
Processes, Threads and System Calls · Memory Management and Virtual Memory
GATE CS 2023, Q.57
Consider the following two-dimensional array in the C programming language, which is stored in row-major order: int D[128][128]; Demand paging is used for allocatin...
Memory Management and Virtual Memory
GATE CS 2023, Q.58
Consider a computer system with 57-bit virtual addressing using multi-level tree-structured page tables with levels for virtual to physical address translation. The page siz...
Memory Management and Virtual Memory · Memory Hierarchy: Cache, Main Memory and Secondary Storage
GATE CS 2022, Q.38
Which one of the following statements is FALSE?
Memory Management and Virtual Memory
GATE CS 2022, Q.64
Consider a demand paging system with four page frames (initially empty) and LRU page replacement policy. For the following page reference string…
Memory Management and Virtual Memory
GATE CS 2021 Set 1, Q.21 (CS Q.11)
In the context of operating systems, which of the following statements is/are correct with respect to paging?
Memory Management and Virtual Memory
GATE CS 2021 Set 2, Q.58 (CS Q.48)
Consider a three-level page table to translate a 39-bit virtual address to a physical address as shown below. A 39-bit virtual address bit layout divided into four fields: Level...
Memory Management and Virtual Memory
GATE CS 2020, Q.21 (CS Q.11)
Consider allocation of memory to a new process. Assume that none of the existing holes in the memory will exactly fit the process's memory requirement. Hence, a new hole of smal...
Memory Management and Virtual Memory
GATE CS 2020, Q.63 (CS Q.53)
Consider a paging system that uses 1-level page table residing in main memory and a TLB for address translation. Each main memory access takes 100 ns and TLB lookup takes 20 ns....
Memory Management and Virtual Memory · Memory Management and Virtual Memory
GATE CS 2019, Q.43 (CS Q.33)
Assume that in a certain computer, the virtual addresses are 64 bits long and the physical addresses are 48 bits long. The memory is word addressable. The page size is 8 kB and...
Memory Management and Virtual Memory
GATE CS 2018, Q.20 (CS Q.10)
Consider a process executing on an operating system that uses demand paging. The average time for a memory access in the system is M units if the corresponding memory page is av...
Memory Management and Virtual Memory
GATE CS 2017 Set 1, Q.40 (CS Q.40)
Recall that Belady's anomaly is that the page-fault rate may increase as the number of allocated frames increases. Now, consider the following statements: S1: Random page replac...
Memory Management and Virtual Memory
GATE CS 2016 Set 1, Q.57 (CS Q.47)
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 e...
Memory Management and Virtual Memory
GATE CS 2016 Set 1, Q.59 (CS Q.49)
Consider a computer system with ten physical page frames. The system is provided with an access sequence , where each i...
Memory Management and Virtual Memory
GATE CS 2016 Set 2, Q.30 (CS Q.20)
In which one of the following page replacement algorithms it is possible for the page fault rate to increase even when the number of allocated frames increases?
Memory Management and Virtual Memory
GATE CS 2015 Set 1, Q.22 (CS Q.12)
Consider a system with byte-addressable memory, 32-bit logical addresses, page size and page table entries of each. The size of the page tab...
Memory Management and Virtual Memory
GATE CS 2015 Set 1, Q.57 (CS Q.47)
Consider a main memory with five page frames and the following sequence of page references: . Which one of the following is true wit...
Memory Management and Virtual Memory
GATE CS 2015 Set 2, Q.35 (CS Q.25)
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...
Memory Management and Virtual Memory
GATE CS 2015 Set 2, Q.40 (CS Q.30)
Consider six memory partitions of sizes 200 KB, 400 KB, 600 KB, 500 KB, 300 KB and 250 KB, where KB refers to kilobyte. These partitions need to be allotted to four processes of...
Memory Management and Virtual Memory
GATE CS 2015 Set 2, Q.57 (CS Q.47)
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 transl...
Memory Management and Virtual Memory
GATE CS 2014 Set 1, Q.43 (CS Q.33)
Assume that there are 3 page frames which are initially empty. If the page reference string is 1, 2, 3, 4, 2, 1, 5, 3, 2, 4, 6, the number of page faults using the optimal repla...
Memory Management and Virtual Memory
GATE CS 2014 Set 2, Q.43 (CS Q.33)
A computer has twenty physical page frames which contain pages numbered 101 through 120. Now a program accesses the pages numbered 1, 2, ..., 100 in that order, and repeats the...
Memory Management and Virtual Memory
GATE CS 2014 Set 3, Q.30 (CS Q.20)
A system uses 3 page frames for storing process pages in main memory. It uses the Least Recently Used (LRU) page replacement policy. Assume that all the page frames are initiall...
Memory Management and Virtual Memory
GATE CS 2014 Set 3, Q.43 (CS Q.33)
Consider a paging hardware with a TLB. Assume that the entire page table and all the pages are in the physical memory. It takes 10 milliseconds to search the TLB and 80 millisec...
Memory Management and Virtual Memory
GATE CS 2013, Q.52 (CS Q.52)
What is the size of a page in KB in this computer?
Memory Management and Virtual Memory
GATE CS 2012, Q.42 (CS Q.42)
Consider the virtual page reference string on a demand paged virtual memory system running on a computer system that has main memory size of 3 p...
Memory Management and Virtual Memory
GATE CS 2011, Q.20 (CS Q.20)
Let the page fault service time be 10 ms in a computer with average memory access time being 20 ns. If one page fault is generated for every memory accesses, what is the...
Memory Management and Virtual Memory