Comparing I/O Management in Computing Systems and Toy Shops
75 Questions
0 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 type of registers does a device typically have for CPU interactions?

  • Command, data, and status registers (correct)
  • Primary, secondary, and tertiary registers
  • Control, management, and communication registers
  • Input, output, and processing registers

    • Which component of a device acts as its CPU?

  • Control register
  • Data register
  • Microcontroller (correct)
  • Bridging controller

    • What type of logic is responsible for converting analog signals in devices?

  • Chips for analog-to-digital conversion (correct)
  • Control registers
  • Control bus
  • Central Processing Unit

    • Which interconnect is described as more technologically advanced than PCI-X and PCI?

    <p>PCI Express</p> Signup and view all the answers

    What is a key property of block devices like disks?

    <p>Access to individual blocks of data</p> Signup and view all the answers

    Which type of devices work with a serial sequence of characters?

    <p>Character devices</p> Signup and view all the answers

    What are device drivers responsible for?

    <p>Device access, management, and control</p> Signup and view all the answers

    What does a bridging controller handle in devices?

    <p>Managing different types of interconnects</p> Signup and view all the answers

    Which logic component is responsible for device-specific CPU operations?

    <p>Microcontroller</p> Signup and view all the answers

    What do network devices deliver?

    <p>A stream of data chunks</p> Signup and view all the answers

    What do user processes interact with at the level of the user process?

    <p>Files</p> Signup and view all the answers

    What standardized API is exposed to user processes by operating systems in file systems?

    <p>POSIX API</p> Signup and view all the answers

    What type of API does the POSIX API consist of?

    <p>System calls for read and write</p> Signup and view all the answers

    What persistent data structure is maintained for each file by the VFS?

    <p>Inode</p> Signup and view all the answers

    What represents the elements on which the Virtual File System (VFS) operates?

    <p>Files</p> Signup and view all the answers

    To help with operations on directories, what data structure does Linux maintain?

    <p>Dentry</p> Signup and view all the answers

    What do user applications interact with when accessing the Virtual File System (VFS)?

    <p>Dentries</p> Signup and view all the answers

    In the file system stack, what layer provides a standard for operating systems to interact with all types of block devices?

    <p>Generic block layer</p> Signup and view all the answers

    What operation can be performed on files using a file descriptor?

    <p>Read</p> Signup and view all the answers

    What allows the block device stack to mask differences among different block devices?

    <p>Generic block layer</p> Signup and view all the answers

    How many CPU accesses are needed to transmit a 1500B packet using 8 byte data registers?

    <p>2</p> Signup and view all the answers

    What additional hardware support is required for Direct Memory Access (DMA) in devices?

    <p>DMA controller</p> Signup and view all the answers

    Why does the memory buffer involved in DMA need to be in physical memory until the transfer completes?

    <p>Because DMA controllers only have access to physical memory</p> Signup and view all the answers

    What is the responsibility of device drivers in the context of device operations?

    <p>Configuring devices for user processes</p> Signup and view all the answers

    What is a driver responsible for in device configurations?

    <p>Ensuring no data loss in device operations</p> Signup and view all the answers

    What is the reverse path of results/events originating on a device?

    <p>Driver -&gt; User Process -&gt; Kernel</p> Signup and view all the answers

    What does OS bypass in device operations allow in user processes?

    <p>Directly accessing device memory/registers</p> Signup and view all the answers

    What is the primary role of the operating system in OS bypass configurations?

    <p>Mapping device memory/registers for users</p> Signup and view all the answers

    How does PIO compare to DMA in terms of efficiency for smaller transfers?

    <p>PIO is more efficient</p> Signup and view all the answers

    What action is required when a user process needs to interact with a hardware device?

    <p>Making a system call to specify the operation</p> Signup and view all the answers

    What is the role of indirect pointers in managing file content?

    <p>Reducing the size of inodes and increasing the addressable file size</p> Signup and view all the answers

    How does a double indirect pointer differ from a single indirect pointer?

    <p>It points to a block of pointers which point to data</p> Signup and view all the answers

    What is a downside of using indirect pointers in file systems?

    <p>Slower file access due to increased number of disk accesses</p> Signup and view all the answers

    How do filesystems use buffer caches to enhance file access?

    <p>By storing data temporarily in main memory to reduce disk accesses</p> Signup and view all the answers

    Which of the following best describes the purpose of I/O scheduling?

    <p>To reduce disk head movement and optimize sequential accesses</p> Signup and view all the answers

    How does prefetching contribute to reducing file access latency?

    <p>By increasing cache hit rates and fetching nearby blocks</p> Signup and view all the answers

    What purpose does journaling serve in file systems?

    <p>To prevent data loss in case of system crashes</p> Signup and view all the answers

    How does a single indirect pointer expand the addressable file content?

    <p>By pointing to a block of pointers that then point to data</p> Signup and view all the answers

    Why do I/O schedulers aim to reduce disk head movement?

    <p>To improve cache hit rates</p> Signup and view all the answers

    What is one advantage of using buffer caches in file systems?

    <p>Reduction of disk accesses</p> Signup and view all the answers

    What is the main focus of I/O management in both toy shop and operating systems?

    <p>Managing the inputs and outputs of the system or shipping department</p> Signup and view all the answers

    What is the role of dedicated handlers or staff in both toy shop and operating systems?

    <p>They manage the inputs and outputs of the system</p> Signup and view all the answers

    What is the purpose of device drivers and interrupt handlers in an operating system?

    <p>They interact with the devices in the system</p> Signup and view all the answers

    What is the role of I/O devices in a system?

    <p>They are hardware components that are specifically tied to receiving inputs or directing outputs</p> Signup and view all the answers

    What is the challenge in managing I/O devices in a system?

    <p>The device space is extremely diverse</p> Signup and view all the answers

    What is the importance of abstracting I/O details from the core processing or application execution?

    <p>It allows the production of toys or execution of applications to rely on both the I/O management and other hardware components</p> Signup and view all the answers

    What is the primary role of the OS in making device registers available to the user process?

    <p>To make registers available on creation and then step out of the way</p> Signup and view all the answers

    Why do we need a user-level driver to interact with the device?

    <p>To not enter the kernel in order to control the device</p> Signup and view all the answers

    What is the purpose of the OS retaining some coarse-grain control?

    <p>To enable/disable devices or add permissions</p> Signup and view all the answers

    What happens when a network device receives a packet and needs to determine its target process?

    <p>It peeks inside the packet to see its port number</p> Signup and view all the answers

    What does the device need to perform on received data to deliver it to the correct process?

    <p>Demultiplexing</p> Signup and view all the answers

    What happens to a user thread when making a synchronous I/O request?

    <p>It gets blocked</p> Signup and view all the answers

    What is the benefit of asynchronous I/O operations?

    <p>It allows the process to continue execution</p> Signup and view all the answers

    What is the purpose of the AMPED in the Flash paper?

    <p>To create a separate helper thread for I/O</p> Signup and view all the answers

    What is a file in the context of block devices?

    <p>A logical storage unit</p> Signup and view all the answers

    What is the purpose of the dentry cache in a filesystem?

    <p>To store all previously visited directories</p> Signup and view all the answers

    What is the role of the superblock in a filesystem?

    <p>To store metadata about the filesystem</p> Signup and view all the answers

    Which filesystem was the default filesystem in Linux until it was replaced by ext3 and ext4?

    <p>ext2</p> Signup and view all the answers

    What is the purpose of a superblock in a block group?

    <p>To store information about the overall block group</p> Signup and view all the answers

    What is the purpose of inodes in a filesystem?

    <p>To store the data structure that describes exactly one file</p> Signup and view all the answers

    What is the benefit of using inodes to index files in a filesystem?

    <p>Easy to perform both sequential and random accesses to the file</p> Signup and view all the answers

    What is the downside of using inodes to index files in a filesystem?

    <p>Limitation on the file size</p> Signup and view all the answers

    How is the limitation on file size addressed when using inodes to index files in a filesystem?

    <p>By using indirect pointers</p> Signup and view all the answers

    What is the purpose of dentries in a filesystem?

    <p>To store all visited directories</p> Signup and view all the answers

    What is the purpose of bitmaps in ext2 filesystem?

    <p>To quickly find free blocks and inodes</p> Signup and view all the answers

    What is the main way in which PCI interconnects devices to the CPUs?

    <p>By making devices accessible in a manner similar to how CPUs access memory</p> Signup and view all the answers

    Which of the following is not a disadvantage of interrupts for device access?

    <p>Interrupts can only be triggered when the device has information for the CPU</p> Signup and view all the answers

    What is the purpose of the Base Address Registers (BAR) in device interactions?

    <p>To act as control registers that map a portion of the system's physical memory into the device's address space</p> Signup and view all the answers

    What type of device interface allows a CPU to transmit a network packet via a network interface card (NIC)?

    <p>Programmed I/O (PIO)</p> Signup and view all the answers

    Which of the following is the correct sequence of steps when a CPU writes to device registers in memory-mapped I/O?

    <p>The CPU writes to the device's registers, which appear as memory locations at a specific physical address, and the integrated PCI controller then routes the access to the appropriate device.</p> Signup and view all the answers

    How does a process running on the CPU transmit a network packet via a network interface card (NIC) using Programmed I/O (PIO)?

    <p>By writing to the command register on the device to instruct the device to perform a transmission of the packet data that the CPU will provide</p> Signup and view all the answers

    Which device access model does the I/O Port Model belong to?

    <p>Programmed I/O (PIO)</p> Signup and view all the answers

    Which statement is true about polling devices for device access in CPUs?

    <p>Polling devices can introduce delay in how the event is observed or handled, since the handling happens at some point after the event has been generated by the device.</p> Signup and view all the answers

    Which of the following is the correct order of steps for a CPU to request an operation from an I/O device using Programmed I/O (PIO)?

    <p>Write to the command register on the device, copy the packet into the data registers, and then repeat as necessary until the entire packet is sent</p> Signup and view all the answers

    Which of the following statements is true about Interrupts for device access in CPUs?

    <p>Interrupts can be triggered as soon as the device has information for the CPU, but they can introduce cache pollution and consume CPU cycles.</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser