KernelNewbies:

A glossary of various terms and acronyms related to the Linux kernel. If you know something, please create yourself an account (UserPreferences) and add a term in alphabetical order. Don't be afraid to improve other people's explanations, the goal is to have a high quality document for the readers of this site. If everybody who reads this page adds a term each week, this glossary should be complete within a few months...

Index

[#0-9 0-9]

[#A A]

[#B B]

[#C C]

[#D D]

[#E E]

[#F F]

[#G G]

[#H H]

[#I I]

[#J J]

[#K K]

[#L L]

[#M M]

[#N N]

[#O O]

[#P P]

[#Q Q]

[#R R]

[#S S]

[#T T]

[#U U]

[#V V]

[#W W]

[#X X]

[#Y Y]

[#Z Z]

Anchor(0-9)

0-9


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Outdated interrupt controller present on Intel hardware.

Anchor(A)

A


AIO

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.

Anchor(B)

B


Anchor(C)

C


CBQ

Class Based Queueing, a hierarchical packet fair queueing qdisc. [http://www.icir.org/floyd/cbq.html CBQ Homepage]

Classifier
(also: filter or tcf) classifies a network packet by inspecting it, used by QDiscs.
Context switch
switching the CPU from running one thread to running another thread.
Copy-on-Write
(also: COW) reuse and share existing objects and copy them not until a modification is required.
Current
a kernel variable which points to the task_struct structure of the process currently running on this CPU.

Anchor(D)

D


Device Mapper
A technology for presenting arbitrary groupings of underlying sectors on physical devices in a consistent logical fashion usable by higher level algorithms. Heavily used by kernel technologies such as LVM.
Dwarf
Debugging Information Format

Anchor(E)

E


ELF

Executable Linkable Format, a popular binary format, the default for Linux on most architectures.

ematch
Extended Match, small classification helper attached to classifiers.

Anchor(F)

F


Anchor(G)

G


GRUB

GRand Unified Bootloader, a popular bootloader for Linux, BSD, and other OSes.

Anchor(H)

H


HTB

Hierachical Token Bucket, a qdisc based on TBF and CBQ. [http://luxik.cdi.cz/~devik/qos/htb/manual/theory.htm HTB Theory]

Anchor(I)

I


ISR

Interrupt Service Routine, the function in each device driver that gets called when an interrupt happens.

Anchor(J)

J


Jiffies
An incrementing counter representing system "uptime" in ticks - or the number of timer interrupts since boot. Ultimately the entire original concept of a jiffy will likely vanish as systems use timer events only when necessary and become "jiffyless".

Anchor(K)

K


kswapd
a kernel thread that frees up memory by evicting data from caches and paging out userspace memory, part of the virtual memory subsystem.

Anchor(L)

L


Linux Device Drivers, 3rd Edition

[http://lwn.net/Kernel/LDD3/ online edition].

LKM

Linux Kernel Module. A (often dynamically loadable at system runtime) kernel extension ("driver") to support, for example, some kind of new hardware device or generic software abstraction.

LKML

Linux Kernel Mailing List. The primary virtual watering hole (meeting ground) for kernel developers to share ideas and bounce opinions off oneanother during the course of the kernel development process. FAQ at [http://www.tux.org/lkml/].

LSM
Linux Security Module. a security framework for providing different security levels.
LVM

Logical Volume Management. A technology for providing an arbitrary logical view of underlying data storage in a fashion supporting resizing and restructuring of storage on the fly. Currently in version 2, originally written by Sistina (now Redhat).

LXR

a cross-reference tool that can be used to navigate the Linux kernel source code, available at [http://lxr.linux.no/ lxr.linux.no].

Anchor(M)

M


mem_map
A contiguous virtual array of struct pages representing the entirity of physical memory pages available within a system.
MMU

Memory Management Unit, part of the CPU that is needed for virtual memory.

N

P

Q

R

S

T

U

V

X

Z

KernelNewbies: KernelGlossary (last edited 2006-04-16 13:40:06 by pool-68-160-189-26)