Ingo Molnár, employed by

Red Hat Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide. Red Hat has become ass ...

as of May 2013, is a Hungarian

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

hacker A hacker is a person skilled in information technology who uses their technical knowledge to achieve a goal or overcome an obstacle, within a computerized system by non-standard means. Though the term ''hacker'' has become associated in popu ...

. He is known for his contributions to the operating system in terms of

security Security is protection from, or resilience against, potential harm (or other unwanted coercive change) caused by others, by restraining the freedom of others to act. Beneficiaries (technically referents) of security may be of persons and social ...

and

performance A performance is an act of staging or presenting a play, concert, or other form of entertainment. It is also defined as the action or process of carrying out or accomplishing an action, task, or function. Management science In the work place ...

Life and career

Molnár studied at

Eötvös Loránd University Eötvös Loránd University ( hu, Eötvös Loránd Tudományegyetem, ELTE) is a Hungarian public research university based in Budapest. Founded in 1635, ELTE is one of the largest and most prestigious public higher education institutions in Hung ...

Work

Some of his additions to the Linux

kernel Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learnin ...

include the

O(1) scheduler An O(1) scheduler (pronounced "O of 1 scheduler", "Big O of 1 scheduler", or "constant time scheduler") is a kernel scheduling design that can schedule processes within a constant amount of time, regardless of how many processes are running on the ...

of Linux-2.6.0 and the

Completely Fair Scheduler The Completely Fair Scheduler (CFS) is a process scheduler that was merged into the 2.6.23 (October 2007) release of the Linux kernel and is the default scheduler of the tasks of the SCHED_NORMAL class (i.e., tasks that have no real-time execution ...

of Linux-2.6.23, the in-kernel

TUX Black tie is a semi-formal wear, semi-formal Western dress code for evening events, originating in British and American conventions for clothing, attire in the 19th century. In British English, the dress code is often referred to synecdochically ...

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, ...

FTP The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...

server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

, as well as his work to enhance thread handling. He also wrote a kernel security feature called "

Exec Shield Exec Shield is a project started at Red Hat, Inc in late 2002 with the aim of reducing the risk of worm or other automated remote attacks on Linux systems. The first result of the project was a security patch for the Linux kernel that emulates an ...

", which prevents stack-based

buffer overflow In information security and programming, a buffer overflow, or buffer overrun, is an anomaly whereby a program, while writing data to a buffer, overruns the buffer's boundary and overwrites adjacent memory locations. Buffers are areas of memory ...

exploits in the

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...

architecture by disabling the

execute Execute, in capital punishment, is to put someone to death. Execute may also refer to: *Execution (computing), the running of a computer program * ''Execute'' (album), a 2001 Garage hip-hop album by Oxide & Neutrino * USS ''Execute'' (AM-232), an ...

permission for the stack. Together with Thomas Gleixner, he worked on the real-time preemption (

PREEMPT_RT Preempt (also spelled "pre-empt") is a bid in contract bridge whose primary objectives are (1) to thwart opponents' ability to bid to their best contract, with some safety, and (2) to fully describe one's hand to one's partner in a single bid. A ...

) patch set, which aims to reduce the maximum

thread switching latency In computing, a context switch is the process of storing the state of a process or thread, so that it can be restored and resume execution at a later point, and then restoring a different, previously saved, state. This allows multiple processes ...

of the Linux kernel from an unbounded number of milliseconds to down to bounded values in the order of tens of microseconds (depending on the system). As of 2011, Thomas Gleixner is working on further improving the patch and getting important infrastructure patches of the patch set merged into the Mainline Linux kernel. Between Linux 2.6.21 and Linux 2.6.24, he worked on the

(CFS) which was inspired by the scheduler work of Con Kolivas. CFS replaced the previous

process scheduler In computing, scheduling is the action of assigning ''resources'' to perform ''tasks''. The ''resources'' may be processors, network links or expansion cards. The ''tasks'' may be threads, processes or data flows. The scheduling activity is ca ...

of the Linux kernel with Linux-2.6.23. In 2012 Molnar criticized the

Linux desktop Besides the Linux distributions designed for general-purpose use on desktops and servers, distributions may be specialized for different purposes including computer architecture support, embedded systems, stability, security, localization to a spec ...

as "not free enough" for the users with respect to the applications. He argues that the typically used system of software distribution and deployment by a centrally organized

Linux distribution A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one ...

s is not fast and flexible enough to satisfy the requirements of users and application producers alike. Molnár suggests a decentral deployment method (similar to

Autopackage Autopackage is a free software, free computer package management system aimed at making it simple to create a package that can be installed on all Linux distributions, created by Mike Hearn around 2002. In August 2010, Listaller and Autopackage ...

Zero Install Zero Install is a means of distributing and packaging software for multiple operating systems (Unix-like including Linux and macOS, Windows). Software Rather than the normal method of downloading a software package, extracting it, and install ...

, or the Klik-successor

AppImage AppImage is a format for distributing portable software on Linux without needing superuser permissions to install the application. It tries also to allow Linux distribution-agnostic binary software deployment for application developers, als ...

) which allows a more flexible application infrastructure formed by a stable

platform Platform may refer to: Technology * Computing platform, a framework on which applications may be run * Platform game, a genre of video games * Car platform, a set of components shared by several vehicle models * Weapons platform, a system or ...

and independent software providers. In early 2022, he submitted an RFC on a set of about 2300 patches, called "Fast Kernel Headers", that are intended to improve kernel compile times by 50-80% and at the same time significantly reduce the problems created by the hierarchy and dependencies of include files, the so-called " dependency hell ".Ingo Molnar's patch cover letter
(2022-01-02)

Quotes

On the question, why the

has not been adopted by the mainstream users yet:

References

External links

Ingo Molnár's homepage at Red Hat

Ingo Molnár's RT-kernel homepage

The RT-kernel Wiki

{{DEFAULTSORT:Molnar, Ingo Linux kernel programmers Living people Hungarian computer scientists Year of birth missing (living people) Free software programmers Hungarian computer programmers Red Hat employees