1.5 Resource Management Flashcards
An operating system is a ______ manager.
resource
A program in execution is referred to as a ______.
process
A single-threaded process has one ______ specifying the next instruction to execute.
program counter
The resources that a process needs include CPU time, memory, files, and ______.
I/O devices
When a process terminates, the operating system will reclaim any ______ resources.
reusable
A program is a passive entity, whereas a process is an ______ entity.
active
The execution of a single-threaded process must be ______.
sequential
A multithreaded process has multiple program counters, each pointing to the next instruction to execute for a given ______.
thread
A system consists of a collection of processes, some of which are operating-system processes and the rest are ______ processes.
user
The operating system is responsible for creating and deleting both user and ______ processes.
system
The operating system schedules processes and threads on the ______.
CPUs
The operating system provides mechanisms for process ______.
synchronization
Processes can execute concurrently by multiplexing on a single CPU core or in ______ across multiple CPU cores.
parallel
Processes may be associated with the same program but are considered two separate ______ sequences.
execution
The operating system provides mechanisms for process ______.
communication
The main memory is central to the operation of a modern computer system and is a large array of _______.
bytes
Each byte in main memory has its own _______.
address
Main memory acts as a repository of quickly accessible data shared by the _______ and _______ devices.
CPU, I/O
During the instruction-fetch cycle, the CPU reads instructions from _______.
main memory
In a von Neumann architecture, the CPU both reads and writes data from _______.
main memory
The main memory is generally the only large storage device that the CPU can address and access _______.
directly
For the CPU to process data from disk, the data must first be transferred to _______ by CPU-generated I/O calls.
main memory
Instructions must be in _______ for the CPU to execute them.
memory
For a program to be executed, it must be mapped to absolute addresses and loaded into _______.
memory
As the program executes, it accesses program instructions and data from memory by generating these _______.
absolute addresses
When a program terminates, its memory space is declared _______.
available
To improve CPU utilization and speed of response, general-purpose computers must keep several programs in _______.
memory
Memory management schemes reflect various approaches and the effectiveness of any given algorithm depends on the _______.
situation
When selecting a memory-management scheme, we must consider many factors, especially the _______ design of the system.
hardware
Each memory management algorithm requires its own _______ support.
hardware
The operating system is responsible for keeping track of which parts of memory are currently being used and which _______ is using them.
process
The operating system is responsible for _______ and deallocating memory space as needed.
allocating
The operating system decides which processes and data to move into and out of _______.
memory
The operating system provides a uniform, logical view of information storage to make the computer system convenient for users by abstracting from the physical properties of its storage devices to define a logical storage unit, the _______.
file
File management is one of the most visible components of an _______.
operating system
The most common type of storage is _______ storage.
secondary
_______ storage is also possible alongside secondary storage.
Tertiary
Each type of storage media has its own characteristics and physical _______.
organization
Most storage media are controlled by a device, such as a _______.
disk drive
Properties of storage devices include access speed, capacity, data-transfer rate, and access method (______ or random).
sequential
A file is a collection of related information defined by its _______.
creator
Commonly, files represent programs (both source and object forms) and _______.
data
Data files may be numeric, alphabetic, alphanumeric, or _______.
binary
Files may be free form (for example, text files) or they may be _______ rigidly.
formatted
The concept of a file is an extremely general _______.
one
The operating system implements the abstract concept of a file by managing _______ media and the devices that control them.
mass storage
Files are normally organized into _______ to make them easier to use.
directories
When multiple users have access to files, it may be desirable to control which user may access a file and how that user may access it (for example, ______, write, append).
read
The operating system is responsible for creating and deleting _______.
files
The operating system is responsible for creating and deleting _______ to organize files.
directories
The operating system supports primitives for manipulating files and _______.
directories
The operating system is responsible for mapping files onto _______ storage.
mass
The operating system is responsible for backing up files on _______ storage media.
stable (nonvolatile)
Most modern computer systems use _______ and NVM devices as the principal on-line storage media.
HDDs
Programs such as compilers, web browsers, and games are stored on _______ until loaded into memory.
HDDs
The operating system is responsible for activities related to _______ storage management.
secondary
One of the responsibilities of the operating system in secondary storage management is _______.
mounting and unmounting
Efficient use of secondary storage is crucial because the entire speed of operation of a computer may hinge on the speeds of the _______.
secondary storage subsystem
Some uses for storage that is slower and lower in cost than secondary storage include _______ of disk data.
backups
Tertiary storage devices include _______ drives and their tapes.
magnetic tape
An example of a tertiary storage device is _______.
CD, DVD, or Blu-ray
Tertiary storage is not crucial to system performance, but it still must be _______.
managed
Some operating systems manage tertiary storage while others leave this task to _______.
application programs
Functions that operating systems can provide for tertiary storage include _______ and unmounting media.
mounting
The operating system can allocate and free devices for _______ use by processes.
exclusive
Migrating data from secondary to _______ storage is a function of some operating systems.
tertiary
Information is normally kept in some storage system such as _______.
main memory
When we need a particular piece of information, we first check whether it is in the _______.
cache
If the information is not in the cache, we use the information from the _______.
source
Internal programmable _______ provide a high-speed cache for main memory.
registers
The programmer or compiler implements the _______ and register-replacement algorithms.
register allocation
Most systems have an _______ cache to hold the instructions expected to be executed next.
instruction
Without the instruction cache, the CPU would have to wait several cycles while an instruction was fetched from _______.
main memory
Cache management is an important design problem due to the _______ of caches.
limited size
Careful selection of the cache size and of a _______ can result in greatly increased performance.
replacement policy
The movement of information between levels of a storage hierarchy may be either _______ or implicit.
explicit
Data transfer from cache to CPU and registers is usually a _______ function.
hardware
Transfer of data from _______ to memory is usually controlled by the operating system.
disk
In a hierarchical storage structure, the same data may appear in different _______ of the storage system.
levels
The increment operation proceeds by first issuing an I/O operation to copy the disk block on which A resides to _______.
main memory
The value of A becomes the same only after the new value of A is written from the internal register back to the _______.
hard disk
In a multitasking environment, extreme care must be taken to ensure that each process obtains the most recently updated value of _______.
A
In a multiprocessor environment, each of the CPUs contains a local _______.
cache
The situation where an update to the value of A in one cache is reflected in all other caches is called _______.
cache coherency
In a distributed environment, several copies of the same file can be kept on _______.
different computers
Some distributed systems ensure that when a replica is updated in one place, all other replicas are brought _______ as soon as possible.
up to date
One of the purposes of an operating system is to hide the peculiarities of specific hardware devices from the _____.
user
In UNIX, the peculiarities of I/O devices are hidden from the bulk of the operating system itself by the _____.
I/O subsystem
The I/O subsystem consists of several components, including a memory-management component that includes _____, caching, and spooling.
buffering
The I/O subsystem includes a general _____ interface.
device-driver
Only the _____ knows the peculiarities of the specific device to which it is assigned.
device driver
Interrupt handlers and device drivers are used in the construction of efficient _____ subsystems.
I/O
The I/O subsystem interfaces to the other system components, manages devices, transfers data, and detects _____ completion.
I/O
