about general cachealgorithms detailed algorithms specific to paging page replacement algorithm detailed algorithms specific to the cache between a CPU and RAM CPU cache In computing , cachealgorithms also frequently called replacement algorithms or replacement policies are Optimization computer science ... large datasets sometimes known as cyclic access patterns MRU cachealgorithms have more hits than LRU due to their tendency to retain older data. MRU algorithms are most useful in situations where the older ... may be necessary. Various algorithms also exist to maintain cache coherency . This applies only to situation ... events usenix01 full papers zhou zhou html node3.html Definitions of various cachealgorithms ... class spring2003 cmsc311 Notes Memory direct.html Direct mapped cache DEFAULTSORT CacheAlgorithms Category Cache Category Memory management algorithms de Cache Algorithmus fr Algorithmes de remplacement ... maintained structure can follow to manage a cache of information stored on the computer. When the cache ... rate of a cache describes how often a searched for item is actually found in the cache. More efficient ... cache size . The latency of a cache describes how long after requesting a desired item the cache ... of less usage information or, in the case of direct mapped cache, no information to reduce the amount ... compare the effectiveness of the actually chosen cache algorithm. Least Recently Used Least Recently ... recently used item. General implementations of this technique require keeping age bits for cache lines and track the Least Recently Used cache line based on age bits. In such implementation, every time a cache line is used, the age of all other cache lines changes. LRU is actually Page replacement algorithm Variants on LRU a family of caching algorithms with members including http www.vldb.org ... CPU cache Associativity associativity generally 4 ways , the implementation cost of LRU becomes ..., the PLRU algorithm can be used which only needs one bit per cache item to work. Image Cache,associative ... more details
see Software engineering Cachealgorithms CHS conversion converting between disk addressing systems ...The following is a list of algorithms along with one line descriptions for each. Combinatorial algorithms see Combinatorics General combinatorial algorithms Cycle detection Brent s algorithm Brent s algorithm ... Mersenne twister Graph algorithms see Graph theory Category Graph algorithms Coloring algorithm Graph ... Force based algorithms graph drawing Force based algorithms also known as force directed algorithms ... algorithms for computing the minimum spanning tree of a set of points in the plane Longest path problem ... Gabow algorithm Kosaraju s algorithm Tarjan s algorithm Sequence algorithms see Sequences Approximate ... local sequence alignment Sorting main Sorting algorithms contradict other Sorting algorithm Comparison of algorithms date March 2011 Exchange Sorts Bubble sort for each pair of indices, swap the items ... sort Burstsort build a compact, cache efficient burst trie and then traverse it to create sorted ... suffix tree s Computational mathematics see Computational mathematics see also List of algorithms Combinatorial algorithms l1 Combinatorial algorithms List of algorithms Computational science l2 Computational ... Geometry main Category Geometric algorithms l1 Geometric algorithms see Computational ... between them Collision detection algorithms check for the collision or intersection of two given solids Cone algorithm identify surface points Convex hull algorithms determining the convex hull of a Set ... algorithm Minimum bounding box algorithms find the Minimum bounding box Arbitrarily oriented minimum ... the nearest point or points to a query point Point in polygon algorithms tests whether a given point ... triangulation algorithms decompose a polygon into a set of triangles Voronoi diagram s, geometric duality ... number of dimensions Fortune s Algorithm create voronoi diagram Number theoretic algorithms see Number ... of Atkin Sieve of Eratosthenes Sieve of Sundaram Numerical algorithms see Numerical analysis List of numerical ... more details
orphan date December 2007 XDAIS or eXpressDsp Algorithm Interoperability Standard is a standard for algorithm development by Texas Instruments for the TMS320 DSP family. The standard was first introduced in 1999 and was created to facilitate integration of DSP algorithms into systems without re engineering cost. The XDAIS standard address the issues of algorithm resource allocation and consumption on a DSP. Algorithms that comply with the standard are tested and awarded an eXpressDSP compliant mark upon successful completion of the test The standard consists of a set of general rules and guidelines that should be applied to all algorithms. For instance, all XDAIS compliant algorithms must implement an Algorithm Interface, called IALG. For those algorithms utilizing DMA , the IDMA interface must be implemented. Further, specific rules are provided for each family of TI DSP. Problems are often caused in algorithm by hard coding access to system resources that are used by other algorithms. DAIS prohibits the use of this type of hard coding. Instead, DAIS requires a standard API for the application to call a particular algorithm class. This API is defined in the xDM standard , also referred to as the VISA API s video, imaging, speech and audio . A XDAIS developer s kit provides the standard itself, example code, and a demonstration. Benefits of XDAIS over non standardize approach include Significant reduction in integration time as algorithms do not trash each others resources Easy comparison of algorithms from multiple different sources in the same application Access to broad range of compliant algorithms available from multiple TI DSP Third Parties eliminates need to custom develop complex algorithms Algorithms work out of the box with eXpressDSP Multimedia Framework Products, such as Codec Engine TI See also eXpressDsp External links http focus.ti.com docs toolsw folders print tmdxdaisxdm.html technicaldocuments XpressDSP Algorithm Standard xDAIS Developer s Kit and ... more details
orphan date October 2009 As opposed to persistent data stored in memory medium for access on demand, transient data originated on line streams are lost if not explicitly stored. These transient data, called data stream s, invalid many existing algorithm s for persistent data. Paralleled with persistent data and data streams, streaming algorithm s is coined which process streams with sublinear memory cost. Among many methods of designing algorithms for data streams, streamlizing algorithms to enable algorithms to process data streams is one of possible research directions. Streaming Graph Semi streaming Graphs With given Vertex graph theory vertex set V, edges in edge set is shown one by one ...... External links WebDB.cn Southeast University http sites.google.com site webdbp2p WebDB.cn Southeast University http cse.seu.edu.cn people zhchong Streaming algorithms http en.wikipedia.org wiki Streaming algorithms Data Stream Mining http en.wikipedia.org wiki Data stream mining DEFAULTSORT Streamlizing Algorithms Category Data management ... more details
Infobox book name Introduction to Algorithms title orig translator image Image Clrs3.jpeg thumb image caption Cover of the third edition author Thomas H. Cormen , Charles E. Leiserson , Ron Rivest Ronald L. Rivest , and Clifford Stein illustrator cover artist country USA language English series subject Computer algorithms genre publisher MIT press pub date 2009 english pub date media type pages isbn 978 0 262 03384 8 oclc dewey congress preceded by followed by Image Clrs.jpg thumb Cover of the second edition Introduction to Algorithms is a book by Thomas H. Cormen , Charles E. Leiserson , Ron Rivest Ronald L. Rivest , and Clifford Stein . It is used as the textbook for algorithms courses at many universities. It is also one of the most commonly cited references for algorithms in published papers, citation needed date March 2011 reason We can see that there are many citations, but we need a source corroborating that it s one of the most commonly cited with over 4400 citations documented on CiteSeerX . ref cite web url http citeseerx.ist.psu.edu showciting?cid 1910 title Introduction to Algorithms&mdash ... edition of the book was also known as The Big White Book of Algorithms . With the second edition ... The Big Book of Algorithms . ref http www.csd.uwo.ca jamie .Refs tech books.html Neato Tech Books .... last Cormen coauthors Leiserson, Charles E. Rivest, Ronald L. title Introduction to Algorithms edition ... Cormen coauthors Leiserson, Charles E. Rivest, Ronald L. Stein, Clifford title Introduction to Algorithms ... to Algorithms publisher MIT Press date 2009 isbn 0 262 03384 4 edition 3rd References reflist External links Official websites by http mitpress.mit.edu algorithms MIT Press MIT lecture MIT 6.046J 18.410J Introduction to Algorithms Fall 2005 . Held in part by coauthor Charles Leiserson. Released ... mit6046jf05 introduction algorithms VideoLectures.Net . Video recordings of the lectures ... to Algorithms it Introduzione agli algoritmi zh ... more details
Unreferenced stub auto yes date December 2009 For computer algorithms List of algorithms In elementary arithmetic , a standard algorithm or method is a specific method of computation which is conventionally taught for solving particular mathematical problems. These methods vary somewhat by nation and time, but generally include carrying, borrowing, long division, and long multiplication using a standard notation, and standard formulas for average, area, and volume. Similar methods also exist for procedures such as square root and even more sophisticated functions, but have fallen out of the general mathematics curriculum in favor of calculators or tables and slide rules before them . The concepts of reform mathematics which the NCTM introduced in 1989 favors an alternative approach. It proposes a deeper understanding of the underlying theory instead of memorization of specific methods will allow students to develop individual methods which solve the same problems. Students alternative algorithms are often just as correct, efficient, and generalizable as the standard algorithms, and maintain emphasis on the meaning of the quantities involved, especially as relates to place values something that is usually lost in the memorization of standard algorithms . The development of sophisticated calculators has made manual calculation less important see the note on square roots, above and cursory teaching of traditional methods has created failure among many students. Greater achievement among all types of students is among the primary goals of mathematics education put forth by NCTM . Some researchers such as Constance Kamii have suggested that elementary arithmetic, as traditionally taught, is not appropriate in elementary school. Many first editions of textbooks written to the original 1989 standard such as TERC deliberately discouraged teaching of any particular method, instead ... of the materials. Standards based Education Reform DEFAULTSORT Standard Algorithms Category Mathematics ... more details
and no changes will be applied. Algorithms for solving the atomic commit protocol include the two ... algorithms try to solve the problem of a number of processes agreeing on a common decision. More ... inline 10.1109 BIMNICS.2007.4610083 Asynchronous team algorithms for Boolean Satisfiability , Bionetics2007 ... Distributed Algorithms material here should eventually be absorbed into this article DEFAULTSORT Distributed Algorithms Category Distributed algorithms fr Algorithmique r partie ja ... more details
Navigational Algorithms is a source of information whose purpose is to make available the scientific part of the art of navigation, containing specialized articles and software that implements the various procedures of calculus. The topics covered are Celestial navigation Sight Reduction, Line Of Position, Fix... Positional astronomy RA, GHA, Dec Coastal navigation Range, Bearing, Horizontal angles, IALA... Sailings Rhumbs, Loxodromic, Orthodromic, Meridional parts... Weather , tides Software PC PDA Nautical Almanac, Sailings, Variation, Sextant corrections Advanced navigation Include articles about piloting and astronavigation Corrections for sextant altitude, Sight Reduction with calculator Form & Plotting sheet for celestial LoPs, Celestial Fix 2 LoPs, Celestial Fix n LoPs NA Sight Reduction algorithm, Vector equation of the Circle of Position, Vector Solution for the intersection of two Circles of Equal Altitude, Sight Reduction Matrix solution. Basic marine navigation Include papers about introduction to navigation, tides, naval kinematics, weather and oceanography Navigation shareware This section gives a brief description of the free programs available for navigation. Run under Windows XP, maybe under 95 98 2000 NT Nautical Almanac Ephemerides of the celestial bodies used in navigation. Image NA.png thumb 340px Nautical Almanac GHA Greenwich Hour Angle Dec Declination SD Semidiameter HP Horizontal Parallax CelestialFix Astronavigation solution for sight reduction for n observations made with a marine sextant & running fixes The algorithms implemented are For n 2 observations An analytical solution of the two star sight problem of celestial navigation, James A. Van Allen ref An analytical solution of the two star sight problem of celestial navigation. James A. Van ... site navigationalalgorithms Navigational Algorithms http journals.cambridge.org action displayIssue ... Algorithms ... more details
, Joe Buhler , Hendrik Lenstra , and Leonard Adleman 1991 Lock free and wait free algorithms ... References Reflist DEFAULTSORT Timeline Of Algorithms Category Algorithms Category Computing timelines Algorithms Category Mathematics timelines Algorithms tr Algoritmalar n tarihsel s ralamas ... more details
are useful to the people who actually implement and use algorithms, because they are more precise ... of operations that you could use in practice and therefore there are algorithms that are faster than ... in practice . Shortcomings of empirical metrics Since algorithms are platform independent i.e. a given ... to gauge the comparative performance of a given set of algorithms. Take as an example a program that looks ... programming Smoothed analysis Time complexity includes table of orders for common algorithms Notes ... to Algorithms edition Second publisher MIT Press and McGraw Hill location Cambridge, MA year 2001 isbn 0262032937 others Chapter 1 Foundations pages 3 122 Cite book title Algorithms in C, Parts ... Greene first2 Donald E. last2 Knuth title Mathematics for the Analysis of Algorithms edition Second ... University Press year 2008 isbn 9780521884730 DEFAULTSORT Analysis Of Algorithms Category Computational complexity theory Category Analysis of algorithms ar es An lisis de algoritmos ... more details
been assigned a color, then we have found a solution. There are more sophisticated algorithms to solve ... grids, implementations of Sudoku using algorithms for exact cover typically solve 9x9 Sudoku ... can even be randomized for each solution attempt with no harm to the algorithm. Randomized algorithms ... include simulated annealing , and tabu search . Stochastic based optimisation algorithms are known ... givens Computer algorithms work through increasingly more cycles when searching for Sudokus with 20 ... more details
In computer science , cache coloring also known as page coloring is the process of attempting to allocate free page computer science pages that are contiguous from the CPU cache s point of view, in order to maximize the total number of pages cached by the processor. Cache coloring is typically employed by low level dynamic memory allocation code in the operating system , when mapping virtual memory to physical memory . A virtual memory subsystem that lacks cache coloring is less deterministic with regards to cache performance, as differences in page allocation from one program run to the next can lead to large differences in program performance. Details of operations Empty section date June 2008 Example For example, if page 10 of physical memory is assigned to page 0 of a process virtual memory and the cache can hold 5 pages, the page coloring code will not assign page 15 of physical memory to page 1 of a process s virtual memory. It would, instead, assign page 16 of physical memory. In this way, sequential pages in virtual memory do not contend for the same cache line. Implementations This code adds a significant amount of complexity to the virtual memory allocation subsystem, but the result is well worth the effort. ref name freebsd.org cite web url http www.freebsd.org doc en US.ISO8859 1 articles vm design page coloring optimizations.html title Page Coloring accessdate 2007 01 13 author Matthew Dillon authorlink Matt Dillon computer scientist work Design elements of the FreeBSD VM system publisher FreeBSD Foundation ref Page coloring makes virtual memory as deterministic as physical memory in regard to cache performance. Page coloring is employed in operating system s such as Solaris ... Algorithms for Large Real Indexed Caches , by R. E. Kessler, Mark D. Hill, University of Wisconsin ... document http i30www.ira.uka.de research documents l4ka 1996 colmem.ps here . DEFAULTSORT Cache Coloring Category Cache ... more details
Cache River may refer to The Cache River Arkansas Cache River in Arkansas , site of the Cache River National Wildlife Refuge The Cache River Illinois Cache River in Illinois , site of the Cypress Creek National Wildlife Refuge disambig ... more details
Cache Creek may refer to Cache Creek British Columbia , a stream in the Thompson Country of British Columbia, Canada Cache Creek, British Columbia , a town in British Columbia, Canada, named after the creek Cache Creek Kern County, California , a stream in Kern County, California, United States Cache Creek Oklahoma , a stream in Southwestern Oklahoma, United States Cache Creek Mokelumne River , a Sierra Nevada tributary of the North Fork Mokelumne River Cache Creek Sacramento River , a tributary stream in Yolo, Colusa, and Lake Counties, California, United States Cache Creek Casino Resort , is a casino resort located in Brooks, California dab geo fr Cache Creek ... more details
Disk cache may refer to Disk buffer , the small amount of buffer memory present on a hard drive. Page cache , the cache of disk pages kept by the operating systems, stored in unused main memory. General application level cache caching of data stored on the disk. ReadyBoost , a non volatile disk cache stored on a flash memory device, in Windows Vista and Windows 7. disambig ko zh ... more details
Orphan date July 2009 Unreferenced date August 2009 A Cache c ur French language French for hide the heart is a top clothing top for women, composed of two finished triangular parts, each having a strap. It is closed by overlapping the two segments and tying the straps behind the back or along the side, depending on the length. The triangular shape of the sides makes the garment a type of V neck. DEFAULTSORT Cache Cour Category Clothing clothing stub fr Cache c ur it Cache c ur sv Cache c ur ... more details
selfref For Wikipedia s cache strategy and related concerns, see Wikipedia Cache . Wiktionarypar cache cach Cache may refer to Treasure trove , a valuable cache which has been lost, or left unclaimed by the owner, or a place where items are stored An underground weapons or logistics cache, as used by survivalist s. Geocaching , an outdoor treasure hunting game Hoarding animal behaviour Caching , a food storing behavior of animal s Cache , in computers, a collection of data duplicating original values stored elsewhere Web cache Places Cache, Oklahoma , a city in Comanche County Cache Creek, British Columbia , a junction community northeast of Vancouver, Canada Cache Creek disambiguation , several places Cache Junction, Utah , a census designated place in Cache County, Utah Cach may also refer to Cach film Cach film , a 2005 film directed by Michael Haneke Cach software , a database management system from InterSystems See also Cash , money in the form of liquid currency Cash flow , the balance of the amounts of cash being received and paid by a business during a defined period of time. Cachet , in philately, a design or inscription other than a cancellation or pre printed postage disambig bg de Cache Begriffskl rung fr Cache it Cache disambigua nl Cach ja nrm Cache pl Cache ujednoznacznienie pt Cache desambigua o ru ... more details
Unreferenced date December 2008 Cache invalidation is a process whereby entries in a cache are deleted. It can be done explicitly, as part of a cache coherency protocol in a parallel computing parallel computer . In such a case, a compute node updates changes variable and then invalidates the cached values of that variable across the rest of the computer system. Category Cache coherency Parallel computing storage software stub ... more details
Multiple issues notability December 2009 unreferenced December 2009 pov March 2010 orphan September 2010 context January 2010 Dynamic cache is intelligent microcache using patterns that allow a user to configure cache content, Time to live TTL and cached content cleaning per the user s preference or desire. Dynamic cache makes generation of static pages by means of Content management system CMS unnecessary. Category Cache Compu storage stub ... more details
Image COAST.jpg thumb right 300px A COASt cache module and a Quarter United States coin quarter for size comparison. Image COAST CPU.jpg right thumb 200px 1. CPU Pentium 133 br 2. Tag RAM for CPU cache L2 cache . br 3. Socket for COAST Module. COASt , an acronym for cache on a stick , is a packaging standard for modules containing Static random access memory SRAM used as an CPU cache L2 cache in a computer. COASt modules look like somewhat over sized SIMM modules. These modules were somewhat popular in the Apple and PC platforms during early to mid 1990s, but with newer computers cache is built into either the Central processing unit CPU or the motherboard . COASt modules decoupled the motherboard from its cache, allowing varying configurations to be created. A low cost system could run with no cache, while a more expensive system could come equipped with 512 KB or more cache. Later COASt modules were equipped with Static random access memory pipelined burst SRAM . The standard was originally defined by Motorola to be between 4.33 and 4.36 inches 110 and 111 mm wide, and between 1.12 and 1.16 inches 28 and 29 mm high. It could be found in many Macintosh Apple Macintosh in the early to mid 90s, but disappeared as the Mac moved to the PowerPC platform. Intel Corporation Intel also used the COASt standard for their Intel P5 Pentium systems, where it could be found as late as 1998 in Pentium ... both the CPU and separate cache chips. The slot that the COASt module plugged into was named CELP , or card ... http www.pcguide.com ref mbsys cache structCOASt c.html COASt Modules , PCGuide, April 17, 2001. http www.pcguide.com proc physinst coast.htm Cache Module Physical Installation Procedure , PCGuide, April 17, 2001. Renn, Brian. http www.cs.umd.edu class fall2001 cmsc411 projects ramguide cache cache.html whatCOASt The Cache Guide What is COASt? , December 12, 1998. External links Commons category COAST Category Computer memory id Cache on a stick de Cache on a stick ... more details
Unreferenced date December 2009 Distinguish DNS cache poisoning Cache pollution describes situations where an executing computer program loads data into CPU cache unnecessarily, thus causing other needed data to be evicted from the cache into lower levels of the memory hierarchy , potentially all the way ... T 0 T 0 1 for i in 0..SIZEOF CACHE C i C i 1 T 0 T 0 C SIZEOF CACHE 1 The assumptions here are that the cache ... data is cacheable, the CPU cache Associativity set associativity of the cache is N where N 1 , and at most ..., T 0 will be fetched from memory into cache, its value updated. However, as the loop executes, because the number of data elements the loop references requires the whole cache to be filled to its capacity, the cache block containing T 0 has to be evicted. Thus, the next time the program requests T 0 to be updated, the cache misses, and the cache controller has to request the computer bus data bus to bring the corresponding cache block from main memory again. In this case the cache is said to be polluted ... the corresponding cache block as least recently used i.e. as the prime candidate for eviction upon a need to evict a block from its cache set. To appropriately use that instruction in the context .... When implemented in this manner, cache pollution would not take place, since the execution of such loop would not cause premature eviction of T 0 from cache. This would be avoided because, as the loop would progress, the addresses of the elements in C would map to the same cache way ... the oldest data not pertinent for the example given would be evicted from cache, which T 0 is not a member ... run time overhead is overwhelmingly larger than any gain achievable by cache pollution avoidance unless the memory region has been non cacheable to begin with . Often in real life the cache is composed of more than one level called the L1 , L2 etc. . Therefore, cache pollution is well defined only for situations where the term cache is unambiguous. Otherwise, it is imperative to specify which level ... more details
The Download Cache , or downloaded files cache, is a component of Microsoft s .NET Framework that is similar to the Global Assembly Cache except that it caches .NET assembly assemblies that have been downloaded from the Internet . ref http msdn2.microsoft.com en us magazine cc164080.aspx Basic Instincts Deploying Assemblies Bot generated title ref Assemblies are downloaded from the Internet when a specific Managed code managed Object computer science object is requested using the code < object code HTML element tag in a web page . For example, the following HTML will cause Internet Explorer to download MyAssembly.dll to the Download Cache and will subsequently Object lifetime instantiate MyControl on the page that contains it. code < object id myControlId classid http MyServer MyVirtualFolder MyAssembly.dll MyNamespace.MyControl code code < param name MyProperty value SomeStringValue code code < object code Usage Like the GAC, the Download Cache can be accessed with gacutil.exe ref http msdn2.microsoft.com en us library ex0ss12c VS.80 .aspx Global Assembly Cache Tool Gacutil.exe Bot generated title ref . One can list the contents of the Download Cache using the command pre gacutil.exe ldl pre One can delete the contents of the Download Cache using the command pre gacutil.exe cdl pre References reflist Category .NET framework ... more details
Dictionary Cache The Oracle data dictionary is a collection of database tables, owned by the SYS and SYSTEM schemas, that contain the metadata about the database, its structures, the privileges and roles of database users. The data dictionary cache holds cached blocks from the data dictionary. Data blocks from tables in the data dictionary are used continually to assist in processing user queries and other DML commands. If the data dictionary cache is too small, requests for information from the data dictionary will cause extra I O to occur these I O bound data dictionary requests are called recursive calls and should be avoided by sizing the data dictionary cache correctly. Fast Access Oracle constantly accesses the data dictionary during database operation to validate user access and to verify the state of schema objects. All information is stored in memory using the least recently used LRU algorithm. The data dictionary cache is accessed for each SQL statement at parse time and again at runtime when the SQL gathers dynamic storage for execution. Dictionary Cache Hit Ratio The data dictionary cache hit ratio is used to measure the ratio of dictionary hits to misses meaning how many times dictionary cache has the dictionary tables data blocks for requested information and how many times Oracle has to do I O for missing on cache. For optimal performance, the overall dictionary cache hit ratio should be greater than 90 To monitor the efficiency of the Data Dictionary Cache, below sql statement can be used class wikitable border 1 select 1 sum getmisses sum gets sum getmisses 100 Dictionary Hit Rate from v rowcache A figure of between 90 95 should be maintained if the rate starts to drop, SHARED POOL SIZE should be increased Category Database stubs Category Oracle Corporation ... more details
Distinguish Cache miss Unreferenced date December 2009 In computer programming , negative cache is a cache that also stores negative responses, i.e. failures. This means that a program remembers the result indicating a failure even after the cause has been corrected. Usually negative cache is a design choice, but it can also be a software bug . Examples Consider a web browser which attempts to load a page while the network is unavailable. The browser will receive an error code indicating the problem, and may display this error message to the user in place of the requested page. However, it is incorrect for the browser to place the error message in the page cache, as this would lead it to display the error again when the user tries to load the same page even after the network is back up. The error message must not be cached under the page s Uniform Resource Locator URL until the browser is able to successfully load the page, whenever the user tries to load the page, the browser must make a new attempt. A frustrating aspect of negative caches is that the user may put a great effort into troubleshooting the problem, and then after determining and removing the root cause, the error still does not vanish. There are cases where failure like states must be cached. For instance, Domain Name System DNS requires that caching nameservers remember negative responses as well as positive ones ..., to the nameserver caching it, it is not a failure. The cache times for negative and positive caching may be tuned independently. Description A negative cache is normally only desired if failure is very ... a clear indication of what must be done to clear the cache, in addition to a description of the cause of the error. In such conditions a negative cache is an example of a design anti pattern . See also Perl Design Patterns Book DEFAULTSORT Negative Cache Category Programming bugs Category Software anomalies Category Cache Compsci stub ... more details
In computing, page cache , sometimes ambiguously called disk cache , is a transparent buffer of disk backed pages kept in main memory RAM by the operating system for quicker access. Page cache is typically implemented in kernel computer science kernel s with the paging memory management, and is completely transparent to applications. All memory that is not directly allocated to applications is usually utilized for page cache. Hard disk read speeds are low and random access es require expensive disk seek s compared to main memory this is why RAM upgrades usually yield significant improvements in computers speed and responsiveness. Fact date February 2007 Separate disk caching is provided on the hardware side, by dedicated RAM or NVRAM chips located either in disk controller inside a hard disk ... should not be confused with page cache. Memory conservation details Demand paging Since non dirty page computing page s in the page cache have identical copies in secondary storage hard disk , discarding ... page cache and mapped to individual process computing process spaces using virtual memory this is done ... out of main memory eventually, leading to memory conservation. Since cache pages can be easily dropped and re used, some operating systems, notably Windows NT , even report the page cache usage as free ... the utilization of page cache in Windows. Page cache and disk writes The page cache also aids in writing ... block is looked up. If it is already found in cache, the write is done to that page in memory ... modifications are done. A file that is created or opened in the page cache, but not written ... commercially available page cache disk cache for microcomputers was MicroCache from Microcosm ... added a disk cache to MS DOS version 4.01 in 1988. They called it SmartDrive . See also Cache Demand ... title Swapping and the Page Cache in Linux url http home.earthlink.net jknapka linux mm pagecache.html ... simple Page cache ... more details
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