Non Contiguous Memory Allocation Quiz
10 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is non-contiguous memory allocation?

  • Dividing memory into fixed-sized partitions for each process
  • Allocating memory in a continuous, uninterrupted manner
  • Partitioning a program into small units that can reside in different parts of the memory (correct)
  • Assigning memory address to segments sequentially

    • What are the segments in segmented memory allocation?

  • Segments of different sizes allocated dynamically
  • Global variables, common block, stack, local variables, symbol table
  • Structural modules that determine segments and need Segment Table
  • Main program, subroutine A, subroutine B (correct)

    • What is required in the addressing scheme for segmented memory allocation?

  • Memory partitioning information
  • Only the memory address of the main program
  • Segment number and displacement/offset (correct)
  • Physical memory addresses for all segments

    • What is an advantage of segmented memory allocation?

    <p>External fragmentation is eliminated</p> Signup and view all the answers

    What is the purpose of the segment table in memory?

    <p>To store the starting physical address where the segments reside in memory</p> Signup and view all the answers

    How is a two-dimensional logical address mapped to a one-dimensional physical address in the segmentation process?

    <p>By using a segment table with base and limit values</p> Signup and view all the answers

    What is the main disadvantage of dynamically allocated memory in the context of variable-length segments?

    <p>Difficulty managing variable-length segments in secondary storage</p> Signup and view all the answers

    In the context of paging, what does the term 'internal fragmentation' refer to?

    <p>Wasted space within a page due to page size being larger than the data size</p> Signup and view all the answers

    What is the role of the page table in the paging process?

    <p>To translate logical addresses to physical addresses</p> Signup and view all the answers

    What does the page number (p) refer to in the paging hardware?

    <p>The index into a page table containing base addresses of each page in physical memory</p> Signup and view all the answers

    Study Notes

    Memory Allocation

    • Non-contiguous memory allocation refers to a technique where a program's memory is divided into multiple segments, each of which can be allocated separately, allowing for more efficient use of memory.

    Segmented Memory Allocation

    • Segmented memory allocation divides a program's memory into multiple segments, including:
      • Code segment
      • Data segment
      • Stack segment
      • Heap segment
    • Each segment has a base address and a limit, which define the range of addresses that can be used within that segment.

    Addressing Scheme for Segmented Memory Allocation

    • The addressing scheme for segmented memory allocation requires a two-dimensional logical address, consisting of:
      • Segment number (s)
      • Offset (d)
    • This allows the system to calculate the physical address using the segment table.

    Advantages of Segmented Memory Allocation

    • One advantage of segmented memory allocation is that it allows multiple programs to share the same code segment, reducing memory usage.

    Segment Table

    • The segment table is a data structure that stores the base address and limit of each segment, allowing the system to map logical addresses to physical addresses.

    Mapping Logical to Physical Address

    • In the segmentation process, a two-dimensional logical address (s, d) is mapped to a one-dimensional physical address using the segment table, which provides the base address of the segment, and the offset, which is added to the base address to calculate the physical address.

    Disadvantages of Dynamic Memory Allocation

    • The main disadvantage of dynamically allocated memory in the context of variable-length segments is that it can lead to fragmentation, where free memory is broken into small, non-contiguous blocks, making it difficult to allocate large blocks of memory.

    Paging

    • Internal fragmentation in the context of paging refers to the wasted space within a page, resulting from the fact that the page size is fixed, but the amount of data to be stored may not exactly fill the page.

    Page Table

    • The page table is a data structure that stores the mapping of logical page numbers to physical page numbers, allowing the system to translate logical addresses to physical addresses.

    Paging Hardware

    • In the paging hardware, the page number (p) refers to the logical page number, which is used to index the page table to retrieve the corresponding physical page number.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge of non-contiguous memory allocation, which involves partitioning a program into small units that can reside in different memory locations with the help of hardware support. Learn about memory-management schemes and segment as logical units like global variables, stack, local variables, and more.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser