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Slab Allocation
Slab allocation is a memory management mechanism intended for the efficient memory allocation of objects. In comparison with earlier mechanisms, it reduces fragmentation caused by allocations and deallocations. This technique is used for retaining allocated memory containing a data object of a certain type for reuse upon subsequent allocations of objects of the same type. It is analogous to an object pool, but only applies to memory, not other resources. Slab allocation was first introduced in the Solaris 2.4 kernel by Jeff Bonwick. Bonwick claims the name "Slab" comes from a Kellogg's cereal commercial catchphrase rhyme, "grab a slab". Slab allocation is now widely used by many Unix and Unix-like operating systems including FreeBSD and Linux,M. Tim JonesAnatomy of the Linux slab allocator both in the SLAB allocator and its replacement, SLUB.Vlastimil Babkaremove the SLAB allocator/ref> Basis Slab allocation significantly reduces the frequency of computationally costl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management
Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of Resource management (computing), resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single Process (computing), process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of Random-access memory, RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Page Size
A page, memory page, or virtual page is a fixed-length contiguous block of virtual memory, described by a single entry in a page table. It is the smallest unit of data for memory management in an operating system that uses virtual memory. Similarly, a page frame is the smallest fixed-length contiguous block of physical memory into which memory pages are mapped by the operating system. A transfer of pages between main memory and an auxiliary store, such as a hard disk drive, is referred to as paging or swapping. Explanation Computer memory is divided into pages so that information can be found more quickly. The concept is named by analogy to the pages of a printed book. If a reader wanted to find, for example, the 5,000th word in the book, they could count from the first word. This would be time-consuming. It would be much faster if the reader had a listing of how many words are on each page. From this listing they could determine which page the 5,000th word appears on, and ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-size Blocks Allocation
Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system performance. The system allows a computer to appear as if it may have more m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illumos
Illumos (stylized as "illumos") is a partly free and open-source Unix operating system. It has been developed since 2010 and is based on OpenSolaris, after the discontinuation of that product by Oracle. It comprises a kernel, device drivers, system libraries, and utility software for system administration. Its core has become the base for many different open-sourced Illumos distributions, in a way similar to how the Linux kernel is used in different Linux distributions. Name The maintainers write ''illumos'' in lowercase, since some computer fonts do not clearly distinguish a lowercase ''L'' from an uppercase ''i'': ''Il'' (see homoglyph). The project name is a combination of words ''illuminare'' from the Latin for ''to light'', and ''OS'' for ''Operating System''. History and development Illumos was announced via webinar on 3 August 2010, as a community effort of a group of core Solaris engineers to create a truly open source Solaris, by swapping closed sourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memcached
Memcached (pronounced variously /mɛmkæʃˈdiː/ ''mem-cash-dee'' or /ˈmɛmkæʃt/ ''mem-cashed'') is a general-purpose distributed memory-caching system. It is often used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source (such as a database or API) must be read. Memcached is free and open-source software, licensed under the Revised BSD license. Memcached runs on Unix-like operating systems (Linux and macOS) and on Microsoft Windows. It depends on the libevent library. Memcached's APIs provide a very large hash table distributed across multiple machines. When the table is full, subsequent inserts cause older data to be purged in least recently used (LRU) order. Applications using Memcached typically layer requests and additions into RAM before falling back on a slower backing store, such as a database. Memcached has no internal mechanism to track misses which may happen. However, some third p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Perl originally was not capitalized and the name was changed to being capitalized by the time Perl 4 was released. The latest release is Perl 5, first released in 1994. From 2000 to October 2019 a sixth version of Perl was in development; the sixth version's name was changed to Raku. Both languages continue to be developed independently by different development teams which liberally borrow ideas from each other. Perl borrows features from other programming languages including C, sh, AWK, and sed. It provides text processing facilities without the arbitrary data-length limits of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBSD
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems. The NetBSD project focuses on code clarity, careful design, and portability across many computer architectures. Its source code is publicly available and Permissive free software licence, permissively licensed. History NetBSD was originally derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, Berkeley, via its Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-UX
HP-UX (from "Hewlett Packard Unix") is a proprietary software, proprietary implementation of the Unix operating system developed by Hewlett Packard Enterprise; current versions support HPE Integrity Servers, based on Intel's Itanium architecture. It is based on Unix System V (initially Unix System III, System III) and first released in 1984. Earlier versions of HP-UX supported the HP Integral PC and HP 9000 Series 200, 300, and 400 computer systems based on the Motorola 68000 series of processors, the HP 9000 Series 500 computers based on HP's proprietary HP FOCUS, FOCUS architecture, and later HP 9000 Series models based on HP's PA-RISC instruction set architecture. HP-UX was the first Unix to offer access-control lists for file access permissions as an alternative to the standard Unix permissions system. HP-UX was also among the first Unix systems to include a built-in logical volume management, logical volume manager. HP has had a long partnership with Veritas Software, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nintendo Switch
The is a video game console developed by Nintendo and released worldwide in most regions on March 3, 2017. Released in the middle of the Eighth generation of video game consoles, eighth generation of home consoles, the Switch succeeded the Wii U and competed with Sony Interactive Entertainment, Sony's PlayStation 4 and Microsoft's Xbox One; it also competes with the Ninth generation of video game consoles, ninth generation consoles, the PlayStation 5 and Xbox Series X and Series S, Xbox Series X/S. The Switch is a Tablet computer#Gaming tablet, tablet that can either be docking station, docked for home video game console, home console use or used as a handheld game console, portable device, making it a Video game console#Hybrid video game consoles, hybrid console. Its wireless Joy-Con controllers function as two halves of a standard controller and alternatively as individual controllers, featuring buttons, directional analog sticks for user input, motion sensing, and tactile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haiku (operating System)
Haiku, originally OpenBeOS, is a Free and open-source software, free and open-source operating system for personal computers. It is a community-driven continuation of BeOS and aims to be Binary-code compatibility, binary-compatible with it, but is largely a reimplementation with the exception of certain components like the Deskbar. The Haiku project began in 2001, supported by the Nonprofit organization, nonprofit Haiku Inc., and the operating system remains in Beta software, beta. History and project On 17 August 2001 Palm, Inc. announced the purchase of Be, Inc., marking the end of BeOS development. The day after, Michael Phipps started the OpenBeOS project to support the BeOS user community by creating an open-source, Backward compatibility, backward-compatible replacement for BeOS. Palm refused to license the BeOS code to a third-party, meaning that OpenBeOS had to be reverse engineer, reverse-engineered. In 2003, Phipps founded the non-profit organization Haiku, Inc. in Roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Mach
GNU Mach is an implementation of the Mach microkernel. It is the default microkernel in the GNU Hurd. GNU Mach runs on IA-32 machines. GNU Mach is maintained by developers on the GNU project. It is distributed under the terms of the GNU General Public License (GPL). History Early versions of the Hurd were developed on top of CMU's Mach 3.0. In 1994, CMU stopped working on Mach, and the GNU Project switched to the University of Utah's Mach 4. The kernel known as "GNU Mach" was derived from Mach 4 once Utah stopped development. The first ChangeLog entry by Thomas Bushnell (rather than by a Utah researcher) is from 16 December 1996. In 2002, Roland McGrath branched the OSKit-Mach branch from GNU Mach 1.2, intending to replace all the device drivers and some of the hardware support with code from OSKit. After the release of GNU Mach 1.3, this branch was intended to become the GNU Mach 2.0 main line; however, as of 2006, OSKit-Mach is not being developed due to lack of activity in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DragonFly BSD
DragonFly BSD is a free and open-source Unix-like operating system forked from FreeBSD 4.8. Matthew Dillon, an Amiga developer in the late 1980s and early 1990s and FreeBSD developer between 1994 and 2003, began working on DragonFly BSD in June 2003 and announced it on the FreeBSD mailing lists on 16 July 2003. Dillon started DragonFly in the belief that the techniques adopted for threading and symmetric multiprocessing in FreeBSD 5 would lead to poor performance and maintenance problems. He sought to correct these anticipated problems within the FreeBSD project. Due to conflicts with other FreeBSD developers over the implementation of his ideas, his ability to directly change the codebase was eventually revoked. Despite this, the DragonFly BSD and FreeBSD projects still work together, sharing bug fixes, driver updates, and other improvements. Dillon named the project after photographing a dragonfly in his yard, while he was still working on FreeBSD. Intended as the log ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
