[http://foldoc.doc.ic.ac.uk Free On-Line Dictionary Of Computing]
[http://www.nist.gov/dads/ Dictionary of Algorithms, Data Structures, and Problems]
[http://www.memorymanagement.org/glossary/full.html Memory Management Glossary]
- 2Q algorithm
- MM algorithm based on two areas, one managed as a FIFO queue, and one as an LRU list.
- 8259 PIC
- Outdated interrupt controller present on Intel hardware.
Accelerated Graphics Port, on x86 boxes.
Asynchronous IO, IO that is performed without the issuing process blocking on IO completion.
- Anticipatory Scheduler
- A disk IO scheduler that leaves the disk idle after a read, in anticipation of the next read.
- Anonymous page
- Anonymous buffer
Advanced Linux Sound Architecture.
- See local APIC and IO-APIC.
Advanced Power Management, power management standard superseded by ACPI. APM and SMP just don't mix.
Professor Andrew S. Tanenbaum, author of MINIX and several essential O/S books.
ATA Packet Interface, used by most CD-ROMs, and other devices.
Adaptive Quality of Service Architecture.
Base Address Registers, for PCI devices.
Binary-Coded Decimal - see a textbook.
- See highmem.
- big lock
- bit error
- block bitmap
- bottom-half handler
- bounce buffer
BootStrap Processor, or the CPU which enables the other CPUs in an SMP system.
Branch Target Buffer, on x86 processors, the cache of recent conditional jump results.
- buddy allocator
- buffer cache
- buffer head
- Used in kernel code in tests for "impossible" conditions. Signify a kernel bug or faulty hardware.
- bus mastering
- byte sex
- cache affinity
- cache coherency
- cache line
- cache ping-pong
- cache pollution
- call gate
Completely Fair Scheduler
- chroot jail
- (also: filter or tcf) classifies a network packet by inspecting it, used by QDiscs.
- cold cache
- A cache whose content is invalid or irrelevant with respect to some task to be run.
- completion ports
- Context switch
Current Privilege Level
- critical path
- Device Mapper
Directed Acyclic Graph
- dancing makefiles
- delayed write
- See write behind.
- demand zero
- directory notification
Dial-On-Demand for net connections over POTS.
- drop behind
- Processors such as the Pentium Pro, that can decode and execute two instructions simultaneously.
- Abbrev. fr. duplication.
- Debugging Information Format
- Double word, i.e. 4 bytes on x86.
- See extended attributes.
- eager coalescing
- What the buddy allocator currently does, i.e. merge adjacent blocks as soon as possible.
- edge-triggered interrupt
- elevator algorithm
Executable Linkable Format, a popular binary format, the default for Linux on most architectures.
- Extended Match, small classification helper attached to classifiers.
- exponential back-off
- extended attributes
- fair scheduler
- false sharing
- The mapping of a file's contents into memory.
- "guages" filesystem-based view of kernel objects
- "knobs" filesystem-based manager of kernel objects, or config_items
- repository for all things task related,
- devices (with various exceptions, contradictions, confusions, and hysterical raisins ...)
- fixed mmap
Fully-Qualified Domain Name, e.g. martyr.darrenemerson.co.uk.
For AGP setups, Graphics Aperture Relocation Table.
- GNOME's source documentation system (similar to javadoc). Available by CVS from gnome. Kernel ["driver"] interface descriptions, built from source using gdoc, are currently being written in 2.3.
Global Descriptor Table. Something to do with x86 memory segmentation I think (FIXME). See ldt.
Generalised Kernel Hook Infrastructure, an IBM patch to implement hooks into the kernel code.
- group descriptor
GRand Unified Bootloader, a popular bootloader for Linux, BSD, and other OSes.
Global System Interrupt. Mainly used in the context of ACPI. [http://lkml.org/lkml/2004/11/11/224 Stupid acronym]
Inter-Process Communication, a set of techniques for the exchange of data among multiple threads in one or more processes.
IP Virtual Server, the kernel part of the LVS (Linux Virtual Server) project. IPVS redirects incoming client requests to one of several "real" servers, usually for the purpose of load balancing a service.
- Linux Device Drivers, 3rd Edition
[http://lwn.net/Kernel/LDD3/ online edition].
Linux Security Module. a security framework for providing different security levels.
NAPI ("New API") is a modification to the device driver packet processing framework, which is designed to improve the performance of high-speed networking. See http://www.linux-foundation.org/en/Net:NAPI.
Netfilter is a framework that provides a set of hooks within the Linux kernel for intercepting and manipulating network packets. See http://en.wikipedia.org/wiki/Netfilter and http://www.netfilter.org.
- Communication protocol between kernel and userspace
- Page cache
- Page table
- data structure used by the MMU to translate virtual memory addresses to physical memory addresses.
Per Processor Data Area is the x86 implementation of per-cpu memory.
Page Frame Number, index into the mem_map array which describes physical memory pages.
Process IDentifier (POSIX thread identifier)
Page Mid-level Directory, note that pmds are folded into pgds on systems with 2 level page tables.
- Process descriptor
- kernel data structure that describes/accounts process data related to a single process.
Page Table Entry
Quality of Service, method to define the importance/priority of network services
Read Copy Update, a mechanism for ["SMPSynchronisation"]
- a lock mechanism that works per process context, see ["SMPSynchronisation"]
- Shared/Paged Socket Buffer
- Slab cache
- a fast, SMP scalable kernel memory allocator.
- Socket Buffer
(also: skb or sk_buff) data structure used to hold the data and attributes of a network packet. See http://www.linux-foundation.org/en/Net:SK_Buff and http://vger.kernel.org/~davem/skb.html for details.
- kind of bottom half rarely used.
- Spin lock
- a simple SMP lock, see ["SMPSynchronisation"]
- Swap token
- System call
A pair of instructions on Pentium2+ that replace older INT instruction based syscall mechanism. See [http://manugarg.appspot.com/systemcallinlinux2_6.html]
- State of a task that is sleeping (not on the run queue). The task will sleep until some event occurs that changes its state to TASK_RUNNING. A task in this state can be awakened by signals.
- State of a task that is on the run queue (but not necessarily running).
- State of a task that has stopped and is not ready to run (happens when a task receives SIGSTOP, SIGTSTP, SIGTTIN or SIGTTOU or when any signal is received while the task is being debugged)
- State of the task that is sleeping (not on the run queue) and must be explicitly awakened. A task in this state can not be awakened by signals.
- State of a task that did called exit() but the parent task didn't call wait4(). The task's descriptor is kept in memory and only released when the parent task calls wait4()
Token Bucket Filter, a qdisc used for rate limiting
Task Group IDentifier (POSIX process identifier)
Virtual File System, an interface through which multiple filesystems can be hooked into the kernel.
- Virtual memory
- every process in the system gets its own memory address space, independent of the other processes.
- Vsyscall page
- see [#VDSO VDSO].