Con Kolivas is an Australian

anaesthetist Anesthesiology, anaesthesiology, or anaesthesia is the medical specialty concerned with the total perioperative care of patients before, during and after surgery. It encompasses anesthesia, intensive care medicine, critical emergency medicine, ...

.Anaesthesia Information Page
by Kolivas, Jan 2001 He has worked as a

computer programmer A computer programmer, sometimes referred to as a software developer, a software engineer, a programmer or a coder, is a person who creates computer programs — often for larger computer software. A programmer is someone who writes/creates ...

on the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...

and on the development of the cryptographic currency mining software CGMiner.CGMiner GitHub repository, "ASIC and FPGA miner in c for bitcoin"
/ref> His Linux contributions include

patch Patch or Patches may refer to: Arts, entertainment and media * Patch Johnson, a fictional character from ''Days of Our Lives'' * Patch (''My Little Pony''), a toy * "Patches" (Dickey Lee song), 1962 * "Patches" (Chairmen of the Board song) ...

es for the kernel to improve its

desktop A desktop traditionally refers to: * The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor) Desktop may refer to various compu ...

performance, particularly reducing I/O impact.

Linux

Kolivas is most notable for his work with CPU scheduling, most significantly his implementation of " fair scheduling", which inspired

Ingo Molnár Ingo Molnár, employed by Red Hat as of May 2013, is a Hungarian Linux hacker. He is known for his contributions to the operating system in terms of security and performance. Life and career Molnár studied at Eötvös Loránd University. Wo ...

to develop his

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 ...

, as a replacement for the earlier

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 ...

, crediting Kolivas in his announcement., 18 April 2007, ''KernelTrap.org'' Kolivas developed several CPU schedulers such as the Staircase in 2004, then Rotating Staircase Deadline (RSDL), and subsequently Staircase Deadline (SD) schedulers to address

interactivity Across the many fields concerned with interactivity, including information science, computer science, human-computer interaction, communication, and industrial design, there is little agreement over the meaning of the term "interactivity", but m ...

concerns of the Linux kernel with respect to desktop computing. Additionally, he has written a " swap prefetch" patch, which allows

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management *Business process, activities that produce a specific se ...

es to respond quickly after the

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

has been idle for some time and their

working set Working set is a concept in computer science which defines the amount of memory that a process requires in a given time interval. Definition Peter Denning (1968) defines "the working set of information W(t, \tau) of a process at time t to be the ...

s have been swapped out. Many of his experimental "-CK" patches, such as his prefetching and scheduling code, did not get merged with the official Linux kernel. In 2007, Kolivas announced in an email that he would cease developing for the Linux kernel. Discussing his reasons in an interview, he expressed frustration with aspects of the mainline kernel development process, which he felt did not give sufficient priority to desktop interactivity, in addition to hacking taking a toll on his health, work and family. He has also written a

benchmark Benchmark may refer to: Business and economics * Benchmarking, evaluating performance within organizations * Benchmark price * Benchmark (crude oil), oil-specific practices Science and technology * Benchmark (surveying), a point of known elevati ...

ing tool called ConTest that can be used to compare the performance of different kernel versions. On 31 August 2009, Kolivas posted a new

scheduler A schedule or a timetable, as a basic time-management tool, consists of a list of times at which possible tasks, events, or actions are intended to take place, or of a sequence of events in the chronological order in which such things are i ...

called BFS (

Brain Fuck Scheduler The Brain Fuck Scheduler (BFS) is a process scheduler designed for the Linux kernel in August 2009 as an alternative to the Completely Fair Scheduler (CFS) and the O(1) scheduler. BFS was created by an experienced kernel programmer Con Koliv ...

). It is designed for desktop use and to be very simple (hence it may not scale well to machines with many CPU cores). Con Kolivas did not intend to get it merged into the mainline kernel.BFS FAQ
/ref> He has since retired BFS in favour of

MuQSS The Brain Fuck Scheduler (BFS) is a process scheduler designed for the Linux kernel in August 2009 as an alternative to the Completely Fair Scheduler (CFS) and the O(1) scheduler. BFS was created by an experienced kernel programmer Con Koli ...

, a rewritten implementation of the same concept.

CGMiner

On 13 July 2011, Kolivas introduced a new piece of software for "windows, linux, OSX and other" called CGMiner, which is used for mining

cryptocurrencies A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank A bank is a financial i ...

such as

bitcoin Bitcoin ( abbreviation: BTC; sign: ₿) is a decentralized digital currency that can be transferred on the peer-to-peer bitcoin network. Bitcoin transactions are verified by network nodes through cryptography and recorded in a public distr ...

and

Litecoin Litecoin (Abbreviation: LTC; sign: Ł) is a decentralized peer-to-peer cryptocurrency and open-source software project released under the MIT/X11 license. Inspired by Bitcoin, Litecoin was among the earliest altcoins, starting in October 2011. ...

References

External links

Kolivas's personal website
{{DEFAULTSORT:Kolivas, Con Australian people of Greek descent Australian computer programmers Australian anaesthetists Linux kernel programmers Medical doctors from Melbourne Living people Year of birth missing (living people)