OPERATING SYSTEM 1. What are the advantages of spooling? The
... OS maintain a list of free holes in main memory ...
... OS maintain a list of free holes in main memory ...
Virtualization
... What is Virtualization? “Virtualization is the simulation of the software and/ or hardware upon which other software runs. This simulated environment is called a virtual machine” --Wikipedia ...
... What is Virtualization? “Virtualization is the simulation of the software and/ or hardware upon which other software runs. This simulated environment is called a virtual machine” --Wikipedia ...
Document
... carier). If it figures that no body is transmitting, it begins to transmit. If two or more Stations decide to transmit at the same time thinking that no body is transmitting, there will be collision. The Station that detects the collision first sends a Jamming signal on the bus (making Noise that th ...
... carier). If it figures that no body is transmitting, it begins to transmit. If two or more Stations decide to transmit at the same time thinking that no body is transmitting, there will be collision. The Station that detects the collision first sends a Jamming signal on the bus (making Noise that th ...
Virtual Memory
... • One goal of two-level paging was to keep individual page tables small. • Suppose we have 40 bit virtual addresses (V = 40) and that – the size of a PTE is 4 bytes – page size is 4KB (212 bytes) – we’d like to limit each page table’s size to 4KB • Problem: for large address spaces, we may need a la ...
... • One goal of two-level paging was to keep individual page tables small. • Suppose we have 40 bit virtual addresses (V = 40) and that – the size of a PTE is 4 bytes – page size is 4KB (212 bytes) – we’d like to limit each page table’s size to 4KB • Problem: for large address spaces, we may need a la ...
CSCI 4717/5717 Computer Architecture
... • Use of levels software dependent • Usually level 3 is for applications, level 1 for O/S and level 0 for kernel (level 2 not used) • Level 2 may be used for apps that have internal security, e.g., database • Some instructions only work in level 0 CSCI 4717 – Computer Architecture ...
... • Use of levels software dependent • Usually level 3 is for applications, level 1 for O/S and level 0 for kernel (level 2 not used) • Level 2 may be used for apps that have internal security, e.g., database • Some instructions only work in level 0 CSCI 4717 – Computer Architecture ...
OPERATING SYSTEMS QUESTIONS
... the data in bulk, and it holds the data on the magnetic medium of the disk.Hard disks have a hard platter that holds the magnetic medium, the magnetic medium can be easily erased and rewritten, and a typical desktop machine will have a hard disk with a capacity of between 10 and 40 gigabytes. Data i ...
... the data in bulk, and it holds the data on the magnetic medium of the disk.Hard disks have a hard platter that holds the magnetic medium, the magnetic medium can be easily erased and rewritten, and a typical desktop machine will have a hard disk with a capacity of between 10 and 40 gigabytes. Data i ...
Operating Systems Sample Exam Questions and Answers Tommy Sailing
... 11. Name some advantages and disadvantages of user-level threads. Advantages of user-level threads include: - Theoretically greater performance, as the OS does not need to perform expensive context switches every time a thread changes. - More configurable, as you are not tied to the kernel to decid ...
... 11. Name some advantages and disadvantages of user-level threads. Advantages of user-level threads include: - Theoretically greater performance, as the OS does not need to perform expensive context switches every time a thread changes. - More configurable, as you are not tied to the kernel to decid ...
Virtual machines - cs.rochester.edu
... • Virtualization softw are must find a w ay to handle paging requests of operating systems, keeping each set of pages separate. • Memory virtualization must not impose too much overhead, or performance and scalability w ill be impaired. • Guest OS must each have an address space, be convinced that i ...
... • Virtualization softw are must find a w ay to handle paging requests of operating systems, keeping each set of pages separate. • Memory virtualization must not impose too much overhead, or performance and scalability w ill be impaired. • Guest OS must each have an address space, be convinced that i ...
page table - Parent Directory
... Page number (p) – used as an index into a page table which contains base address of each page in physical memory Page offset (d) – combined with base address to define the physical memory address that is sent to the memory unit page number ...
... Page number (p) – used as an index into a page table which contains base address of each page in physical memory Page offset (d) – combined with base address to define the physical memory address that is sent to the memory unit page number ...
VMM - UF CISE
... • If plan for VM during design of ISA, easy to reduce instructions executed by VMM, speed to emulate – ISA is virtualizable if can execute VM directly on real machine while letting VMM retain ultimate control of CPU: “direct execution” – Since VMs have been considered for desktop/PC server apps only ...
... • If plan for VM during design of ISA, easy to reduce instructions executed by VMM, speed to emulate – ISA is virtualizable if can execute VM directly on real machine while letting VMM retain ultimate control of CPU: “direct execution” – Since VMs have been considered for desktop/PC server apps only ...
Operating Systems
... • Also usually want to abstract away from grungy harware, i.e. OS provides a virtual machine: – share CPU (in time) and provide each app with a virtual processor, – allocate and protect memory, and provide applications with their own virtual address space, – present a set of (relatively) hardware in ...
... • Also usually want to abstract away from grungy harware, i.e. OS provides a virtual machine: – share CPU (in time) and provide each app with a virtual processor, – allocate and protect memory, and provide applications with their own virtual address space, – present a set of (relatively) hardware in ...
solutions - CIS @ UPenn
... large buffer. To protect against a buffer overflow, programmers can use variations of functions that limit the size of the operation such as strncpy instead of strcpy 2. Prove that if any message can be lost, it is not possible for two processes to agree on non-trivial outcome using only messages fo ...
... large buffer. To protect against a buffer overflow, programmers can use variations of functions that limit the size of the operation such as strncpy instead of strcpy 2. Prove that if any message can be lost, it is not possible for two processes to agree on non-trivial outcome using only messages fo ...
Difference Between Paging and segmentation
... What is Paging? Paging is a memory management method used by operating systems. Paging allows the main memory to use data that is residing on a secondary storage device. These data are stored in the secondary storage device as blocks of same size called pages. Paging allows the operating system to u ...
... What is Paging? Paging is a memory management method used by operating systems. Paging allows the main memory to use data that is residing on a secondary storage device. These data are stored in the secondary storage device as blocks of same size called pages. Paging allows the operating system to u ...
ppt
... CPU deals with interruptions of executions created by errors in the program, user requests, hardware failure, etc., through exceptions, interrupts, and traps. These terms refer to different types of events; we use trap as the generic term. A trap is a special input to the CPU that includes an addres ...
... CPU deals with interruptions of executions created by errors in the program, user requests, hardware failure, etc., through exceptions, interrupts, and traps. These terms refer to different types of events; we use trap as the generic term. A trap is a special input to the CPU that includes an addres ...
Operating Systems and Protection CS 217 1
... o Pro: totally independent operation of each process o Con: lots of extra hardware; some parts idle at any given time; hard limit on the number of processes ...
... o Pro: totally independent operation of each process o Con: lots of extra hardware; some parts idle at any given time; hard limit on the number of processes ...
WORD
... Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
... Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
Study Guide to Accompany Operating Systems Concepts 9 Ed by
... • Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
... • Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
CT213 – Memory Management
... Paged virtual memory • Typical page size is small (1 to 4KB) and in paged systems, a process would require many pages • The limited size of physical memory can cause problems so a portion of the disk storage (or a separate, dedicated high speed storage device) could be used as an extension to the m ...
... Paged virtual memory • Typical page size is small (1 to 4KB) and in paged systems, a process would require many pages • The limited size of physical memory can cause problems so a portion of the disk storage (or a separate, dedicated high speed storage device) could be used as an extension to the m ...
doc
... Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
... Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
PPT - Surendar Chandra
... Operating Systems Operating systems helps juggle resources and makes it appear to have more resources than we actually have Use idle CPU to schedule another process ...
... Operating Systems Operating systems helps juggle resources and makes it appear to have more resources than we actually have Use idle CPU to schedule another process ...
Chapter 1 Bootstrap
... segment registers. The minimum modern expectation is that a processor should have 32-bit registers that can be used directly as addresses. The Intel x86 architecture arrived at those capabilities in two stages of evolution. The 80286 introduced "protected mode" which allowed the segmentation scheme ...
... segment registers. The minimum modern expectation is that a processor should have 32-bit registers that can be used directly as addresses. The Intel x86 architecture arrived at those capabilities in two stages of evolution. The 80286 introduced "protected mode" which allowed the segmentation scheme ...
Study Guide to Accompany Operating Systems Concepts essentials
... • Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
... • Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
WORD
... Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
... Page fault results from the first time there is a reference to a specific page → traps the OS ◦ Must decide to abort if the reference is invalid, or if the desired page is just not in memory yet ▪ If the latter: get empty frame, swap page into frame, reset tables to indicate page now in memory, se ...
memory
... • In case of using virtual memory not all the objects (instructions or data) are in the main memory at a specific time; some of it may be on disk. • Addressing space is divided in fixed length blocks – called pages. • At some moment in time, the pages are in the main memory or on disk. • When the CP ...
... • In case of using virtual memory not all the objects (instructions or data) are in the main memory at a specific time; some of it may be on disk. • Addressing space is divided in fixed length blocks – called pages. • At some moment in time, the pages are in the main memory or on disk. • When the CP ...
PowerPoint - School of Computer Science
... Too many processes in too little memory Operating System spends all its time swapping Little or no real work is done Disk light is on all the time Solutions Good page replacement algorithms Reduce number of processes running Fit more memory ...
... Too many processes in too little memory Operating System spends all its time swapping Little or no real work is done Disk light is on all the time Solutions Good page replacement algorithms Reduce number of processes running Fit more memory ...
Memory management unit
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit having all memory references passed through itself, primarily performing the translation of virtual memory addresses to physical addresses. It is usually implemented as part of the central processing unit (CPU), but it also can be in the form of a separate integrated circuit.An MMU effectively performs virtual memory management, handling at the same time memory protection, cache control, bus arbitration and, in simpler computer architectures (especially 8-bit systems), bank switching.