Reiser4 is a computer file system, successor to the ReiserFS file system, developed from scratch by Namesys and sponsored by DARPA as well as Linspire. Reiser4 was named after its former lead developer Hans Reiser. As of 2018, the Reiser4 patch set is still being maintained, but according to Phoronix, it is unlikely to be merged into mainline Linux without corporate backing.
Cooperative Linux, abbreviated as coLinux, is software which allows Microsoft Windows and the Linux kernel to run simultaneously in parallel on the same machine.
sysfs is a pseudo file system provided by the Linux kernel that exports information about various kernel subsystems, hardware devices, and associated device drivers from the kernel's device model to user space through virtual files. In addition to providing information about various devices and kernel subsystems, exported virtual files are also used for their configuration.
seccomp is a computer security facility in the Linux kernel. seccomp was first devised by Andrea Arcangeli in January 2005 for use in public grid computing and was originally intended as a means of safely running untrusted compute-bound programs. It was merged into the Linux kernel mainline in kernel version 2.6.12, which was released on March 8, 2005. seccomp allows a process to make a one-way transition into a "secure" state where it cannot make any system calls except exit , sigreturn , read and write to already-open file descriptors. Should it attempt any other system calls, the kernel will terminate the process with SIGKILL or SIGSYS. In this sense, it does not virtualize the system's resources but isolates the process from them entirely.
dnotify is a file system event monitor for the Linux kernel, one of the subfeatures of the fcntl call. It was introduced in the 2.4 kernel series. It has been obsoleted by inotify, but will be retained for compatibility reasons.
A kernel is the most fundamental component of a computer operating system. A comparison of system kernels can provide insight into the design and architectural choices made by the developers of particular operating systems.
Squashfs is a compressed read-only file system for Linux. Squashfs compresses files, inodes and directories, and supports block sizes from 4 KiB up to 1 MiB for greater compression. Several compression algorithms are supported. Squashfs is also the name of free software, licensed under the GPL, for accessing Squashfs filesystems.
Wireless network cards for computers require control software to make them function. This is a list of the status of some open-source drivers for 802.11 wireless network cards.
In operating systems, write barrier is a mechanism for enforcing a particular ordering in a sequence of writes to a storage system in a computer system. For example, a write barrier in a file system is a mechanism that ensures that in-memory file system state is written out to persistent storage in the correct order.
debugfs is a special file system available in the Linux kernel since version 2.6.10-rc3. It was written by Greg Kroah-Hartman.
kernel.org is the main distribution point of source code for the Linux kernel, which is the base of the Linux operating system.
The Linux kernel is a free and open-source, monolithic, Unix-like operating system kernel. The Linux family of operating systems is based on this kernel and deployed on both traditional computer systems such as personal computers and servers, usually in the form of Linux distributions, and on various embedded devices such as routers, wireless access points, PBXes, set-top boxes, FTA receivers, smart TVs, PVRs, and NAS appliances. While the adoption of the Linux kernel in desktop computer operating system is low, Linux-based operating systems dominate nearly every other segment of computing, from mobile devices to mainframes.
As of November 2017, all of the world's 500 most powerful supercomputers run Linux. The Android operating system for tablet computers, smartphones, and smartwatches also uses the Linux kernel.
Hans Peter Anvin, known as H. Peter Anvin, or simply Peter Anvin, or even hpa, is a Swedish computer programmer who has distinguished himself by his contributions to Free and open source software projects.
cgroups is a Linux kernel feature that limits, accounts for, and isolates the resource usage of a collection of processes.
zswap is a Linux kernel feature that provides a compressed write-back cache for swapped pages, as a form of virtual memory compression. Instead of moving memory pages to a swap device when they are to be swapped out, zswap performs their compression and then stores them into a memory pool dynamically allocated in the system RAM. Later, writeback to the actual swap device is deferred or even completely avoided, resulting in a significantly reduced I/O for Linux systems that require swapping; the tradeoff is the need for additional CPU cycles to perform the compression.
kGraft is a feature of the Linux kernel that implements live patching of a running kernel, which allows kernel patches to be applied while the kernel is still running. By avoiding the need for rebooting the system with a new kernel that contains the desired patches, kGraft aims to maximize the system uptime and availability. At the same time, kGraft allows kernel-related security updates to be applied without deferring them to scheduled downtimes. Internally, kGraft allows entire functions in a running kernel to be replaced with their patched versions, doing that safely by selectively using original versions of functions to ensure per-process consistency while the live patching is performed.
kpatch is a feature of the Linux kernel that implements live patching of a running kernel, which allows kernel patches to be applied while the kernel is still running. By avoiding the need for rebooting the system with a new kernel that contains the desired patches, kpatch aims to maximize the system uptime and availability. At the same time, kpatch allows kernel-related security updates to be applied without deferring them to scheduled downtimes. Internally, kpatch allows entire functions in a running kernel to be replaced with their patched versions, doing that safely by stopping all running processes while the live patching is performed.
ftrace is a tracing framework for the Linux kernel. Although its original name, Function Tracer, came from ftrace's ability to record information related to various function calls performed while the kernel is running, ftrace's tracing capabilities cover a much broader range of kernel's internal operations.
In the Linux kernel, kernfs is a set of functions that contain the functionality required for creating pseudo file systems used internally by various kernel subsystems. The creation of kernfs resulted from splitting off part of the internal logic used by sysfs, which provides a set of virtual files by exporting information about hardware devices and associated device drivers from the kernel's device model to user space, into an independent and reusable functionality so other kernel subsystems can implement their own pseudo file systems more easily and consistently.
