Buffering is the action I/O devices take in order to efficiently transfer data to or from the operating
system. Instead of directly transferring data bit-by-bit (literally) via system calls and registers, which is slow and requires context switch after context switch, we fill a buffer (or two, or three) with data, which is periodically transferred to or from main program control. We can also perform double or triple buffering where two-way efficiency is gained. It can be advantageous when we need to transfer large volumes of data, and at the same time may be disadvantageous due to overheads – if the network is high-speed the
time to copy between buffers might be comparable to the time spent actually transferring the data!
Titany answered the question on April 26, 2022 at 13:20
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Name and describe four page replacement algorithms. Critically compare them with each other
(Solved)
Name and describe four page replacement algorithms. Critically compare them with each other
Date posted:
April 26, 2022
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Describe two virtual memory page fetch policies. Which is less common in practice? Why?
(Solved)
Describe two virtual memory page fetch policies. Which is less common in practice? Why?
Date posted:
April 26, 2022
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Enumerate some pros and cons for increasing the page size
(Solved)
Enumerate some pros and cons for increasing the page size
Date posted:
April 26, 2022
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What is thrashing? How might it be detected? How might one recover from it once detected?
(Solved)
What is thrashing? How might it be detected? How might one recover from it once detected?
Date posted:
April 26, 2022
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How does page size of a particular architecture affect working set size?
(Solved)
How does page size of a particular architecture affect working set size?
Date posted:
April 26, 2022
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What is the working set of a process?
(Solved)
What is the working set of a process?
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April 26, 2022
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What are temporal locality and spatial locality?
(Solved)
What are temporal locality and spatial locality?
Date posted:
April 26, 2022
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What is an inverted page table? How does it compare to a two-level page table?
(Solved)
What is an inverted page table? How does it compare to a two-level page table?
Date posted:
April 26, 2022
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Answers (1)
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Describe a two-level page table? How does it compare to a simple page table array?
(Solved)
Describe a two-level page table? How does it compare to a simple page table array?
Date posted:
April 26, 2022
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Some TLBs support address space identifiers (ASIDS), why?
(Solved)
Some TLBs support address space identifiers (ASIDS), why?
Date posted:
April 26, 2022
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Describe segmentation-based virtual memory. You should consider the components of a
memory address, the segment table and its contents, and how the final physical address is
formed...
(Solved)
Describe segmentation-based virtual memory. You should consider the components of a
memory address, the segment table and its contents, and how the final physical address is
formed in your answer
Date posted:
April 26, 2022
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Answers (1)
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Give some advantages of a system with page-based virtual memory compared to a simply system with base-limit registers that implements swapping
(Solved)
Give some advantages of a system with page-based virtual memory compared to a simply system with base-limit registers that implements swapping
Date posted:
April 26, 2022
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Answers (1)
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Describe page-based virtual memory. You should consider pages, frames, page
tables, and Memory Management Units in your answer
(Solved)
Describe page-based virtual memory. You should consider pages, frames, page
tables, and Memory Management Units in your answer
Date posted:
April 26, 2022
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Answers (1)
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Base-limit MMUs can support swapping. What is swapping? Can swapping permit an application requiring 16M memory to run on a machine with 8M of RAM?
(Solved)
Base-limit MMUs can support swapping. What is swapping? Can swapping permit an application requiring 16M memory to run on a machine with 8M of RAM?
Date posted:
April 26, 2022
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Answers (1)
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List and describe the four memory allocation algorithms covered in lectures. Which two of the four are more commonly used in practice?
(Solved)
List and describe the four memory allocation algorithms covered in lectures. Which two of the four are more commonly used in practice?
Date posted:
April 26, 2022
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Answers (1)
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Describe the difference between external and internal fragmentation. Indicate which of
the two are most likely to be an issues on a) a simple memory memory...
(Solved)
Describe the difference between external and internal fragmentation. Indicate which of
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using base limit registers and static partitioning, and b) a similar machine using dynamic
partitioning.
Date posted:
April 26, 2022
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Answers (1)
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Why might filesystems managing external storage devices do write-through caching (avoid buffering writes) even though there is a detrimental affect on performance
(Solved)
Why might filesystems managing external storage devices do write-through caching (avoid buffering writes) even though there is a detrimental affect on performance
Date posted:
April 26, 2022
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Answers (1)
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What does flushd do on a UNIX system?
(Solved)
What does flushd do on a UNIX system?
Date posted:
April 26, 2022
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Answers (1)
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What is the maximum file size supported by a file system with 16 direct blocks, single,
double, and triple indirection? The block size is 512 bytes....
(Solved)
What is the maximum file size supported by a file system with 16 direct blocks, single,
double, and triple indirection? The block size is 512 bytes. Disk block numbers can be stored
in 4 bytes.
Date posted:
April 26, 2022
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Answers (1)
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Why might the direct blocks be stored in the inode itself?
(Solved)
Why might the direct blocks be stored in the inode itself?
Date posted:
April 26, 2022
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Answers (1)