Topic: memory management by paging

topics > computer science > operating system > Group: memory management

computer architecture
data caching
file cache
managing shared memory
memory management by working sets
memory management for programs and modules
operating system kernel
security by access rights
security by capabilities
virtual memory


Paging moves blocks of data from disk to memory and back. It is the standard implementation for virtual memory with hardware support for address translation. Page replacement selects a page to remove from memory. (cbb 12/07)
Subtopic: paging up

Quote: manage program memory as pages in uniformly-sized page frames, typically 1024 words; developed by Irons using a small resident program [»hoarCA_1971]
Quote: small fixed-length pages are better than variable length pages; needs hardware support, associative registers [»hoarCA_1971]
Quote: a page in virtual memory is well-defined only if it is contained in exactly one mapped space; AddressFault otherwise [»redeDD2_1980]
Quote: a high paging rate will maximize memory utilization [»hoarCA_1971]
Quote: shed load to stay below the maximum paging rate [»hoarCA_1971]

Subtopic: page replacement up

Quote: page replacement by testing the 'use' bit; called the second chance algorithm [»hoarCA_1971]
Quote: 'use' bit avoids unnecessary paging; LRU is not worth its complexity [»hoarCA_1971]
Quote: pre-select and write the next victim for page replacement; reduces disk latency [»hoarCA_1971]
Quote: least recently/frequently used (LRFU) block replacement policy; up to 30% better than LRU; uses linked list and priority heap based on threshold of recency and frequency value [»leeD9_1997]
Quote: segmented LRU: protected segment of cache hits; halves cache size; two disk accesses tend to indicate many disk accesses [»kareR3_1994]
Quote: freed memory should be reused in a LIFO order. Cyclical reuse may cause memory faults under LRU replacement policies [»wilsPR9_1992]
Quote: LRU does not always work for database buffer management; e.g., one-time sequential access, cyclic referencing, one-time random access [»stonM7_1981]

Subtopic: working set for paging up

Quote: under paged, virtual memory, working-set strategies are better than FIFO disciplines [»oldeRR5_1985]
Quote: in a paging system, the only important thing is to avoid thrashing; otherwise spend all of the time waiting for the disk [»lampBW10_1983]
Quote: in Pilot, users can optimize swapping behavior by dividing program into subspaces with strong locality of reference

Subtopic: page fault handler up

Quote: use the page fault handler to implement quick page accessibility tests; a page fault only occurs on a negative answer [»liedJ1_1994]
Quote: memory compressor assumes all objects are moved, using page protection to trap unmoved objects; copies pages when used [»kermH6_2006]
Quote: Mach tasks may handle page faults and page-out data requests independently of the kernel [»acceM6_1986]
Quote: use page protection to provide access to shared libraries from user-level extensions; data/function pointers stay the same; applications control which pages are accessible [»chiuTC3_1999]

Subtopic: hardware failures up

Quote: Lisa can lock out a memory block with a parity error and continue normal operation [»stewG3_1983]

Subtopic: hardware support up

Quote: Mach's virtual memory is built on hardware page validate, invalidate, and protect
Quote: Mach implements virtual memory with address maps, share maps, VM objects, and page structures
Quote: efficient intra-address space protection by combining segmentation and paging hardware

Related Topics up

Topic: computer architecture (46 items)
Topic: data caching (35 items)
Topic: file cache (23 items)
Topic: managing shared memory (74 items)
Topic: memory management by working sets (18 items)
Topic: memory management for programs and modules (12 items)
Topic: operating system kernel (67 items)
Topic: security by access rights (38 items)
Topic: security by capabilities (65 items)
Topic: virtual memory
(32 items)

Updated barberCB 8/05
Copyright © 2002-2008 by C. Bradford Barber. All rights reserved.
Thesa is a trademark of C. Bradford Barber.