Chap 8 Flashcards
The size of virtual storage is limited by the actual number of main storage locations.
FALSE
The addresses a program may use to reference memory are distinguished from the addresses the memory system uses to identify physical storage sites.
TRUE
Most of the memory management issues confronting the operating system designer are in the are of paging when segmentation is combined with paging.
TRUE
Segmentation is not visible to the programmer.
FALSE
The placement policy determines where in real memory a process piece is to reside.
TRUE
Virtual memory allows for very effective multiprogramming and relieves the user of the unnecessarily tight constraints of main memory.
TRUE
The principle of locality states that program and data references within a process do not tend to cluster.
FALSE
The smaller the page size, the greater the amount of internal fragmentation.
FALSE
The design issue of page size is related to the size of the physical main memory and program size.
TRUE
Segments may be of unequal, indeed dynamic, size.
TRUE
The page currently stored in a frame may still be replaced even when the page is locked.
FALSE
One way to counter the potential performance problems of a variable-allocation global scope policy is to use page buffering.
TRUE
The PFF policy evaluates the working set of a process at sampling instances based on elapsed virtual time.
FALSE
A precleaning policy writes modified pages before their page frames are needed so that pages can be written out in batches.
TRUE
UNIX is intended to be machine-independent; therefore its memory management scheme will vary from one system to the next.
TRUE
The address of a storage location in main memory is the _________.
real address
__________ is the virtual storage assigned to a process.
virtual address space
_________ is the range of memory addresses available to a process.
address space
The _______ structure indexes page table entries by frame number rather than by virtual page number.
inverted page table
The _______ states the process that owns the page.
process identifier
A __________ is issued if a desired page is not in main memory.
page fault
___________ allows the programmer to view memory as consisting of multiple address spaces.
segmentation
_________ is transparent to the programmer and eliminates external fragmentation providing efficient use of main memory.
paging
The _________ determines when a page should be brought into main memory.
fetch policy
With ________ pages other than the one demanded by a page fault are brought in.
prepaging
The _______ policy results in the fewest number of page faults.
optimal
A ________ chooses only among the resident pages of the process that generated the page fault in selecting a page to replace.
local replacement policy
The ________ algorithm requires a use bit to be associated with each page in memory.
page fault frequency
________ is where modified process pages can be written out at the time of replacement, or a precleaning policy can be used, which clusters the output activity by writing out a number of pages at once.
Cleaning policy
_________ is the concept associated with determining the number of processes that will be resident in main memory.
Load control
The address assigned to a location in virtual memory to allow that location to be accessed as though it were part of main memory is the ___________.
virtual address
_________ is the storage allocation scheme in which secondary memory can be addressed as though it were part of main memory.
virtual memory
The size of virtual storage is limited by the addressing scheme of the computer system and by the amount of ___________ available
secondary memory
The ______ policy treats the page frames allocated to a process as a circular buffer and pages are removed in a round robin style.
FIFO
The portion of a process that is actually in main memory at any time is defined to be the ____________ of the process.
resident set
A __________ policy allows the number of page frames allocated to a process to be varied over the lifetime of the process.
variable allocation
Because a process executes only in main memory, that memory is referred to as ______________.
real memory
When the system spends most of its time swapping pieces rather than executing instructions it leads to a condition known as ____________.
thrashing
To overcome the problem of doubling the memory access time, most virtual memory schemes make use of a special high-speed cache for page table entries called a ____________.
translation lookaside buffer
The technique where the processor is equipped with hardware that allows it to interrogate simultaneously a number of TLB entries to determine if there is a match on page number is referred to as ______________.
associative mapping
With _________, a page is brought into main memory only when a reference is made to a location on that page.
demand paging
The ___________ policy replaces the page in memory that has not been referenced for the longest time.
least recently used
The __________ provides a virtual memory capability that allocates page frames in main memory to processes and also allocates page frames to disk block buffers.
paging system
Linux makes use of a three-level page table structure consisting of the following types of tables: page directory, page table, and ___________.
page middle directory
In SVR4 and Solaris systems, the memory management scheme that manages memory allocation for the kernel is called the ____________.
kernel memory allocator
_________ allows the programmer to view memory as consisting of multiple address spaces. Select one:
a. Paging
b. Locality
c. Segmentation
d. Resident set management
c
With _________ pages other than the one demanded by a page fault are brought in. Select one:
a. slab allocation
b. thrashing
c. hashing
d. prepaging
d
_________ is the concept associated with determining the number of processes that will be resident in main memory. Select one:
a. Virtual memory manager
b. Page fault frequency
c. LRU policy
d. Load Control
d
The _________ algorithm requires a use bit to be associated with each page in memory. Select one:
a. page placement
b. working set
c. VSWS
d. page fault frequency
b
