Con Kolivas

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Con Kolivas
Residence	Melbourne, Australia
Occupation	Doctor
Known for	Linux kernel development

Con Kolivas is an Australian anaesthetist ^[1], but he is known on the Internet for his programming work on the Linux kernel in his spare time. He has written patches for the kernel to improve its desktop performance, particularly reducing I/O impact. He has also written a benchmarking tool called ConTest that can be used to compare the performance of different kernel versions.^[2]

Kolivas is most notable for his work with CPU scheduling, most significantly his implementation of "fair scheduling," which inspired Ingo Molnar to develop his Completely Fair Scheduler, as a replacement for the earlier O(1) scheduler, crediting Kolivas in a footnote.^[3] Kolivas developed several CPU schedulers such as the Staircase in 2004^[4], then Rotating Staircase Deadline (RSDL)^[5] and subsequently Staircase Deadline (SD)^[6] schedulers to address interactivity concerns of the Linux kernel with respect to desktop computing. Additionally, he has written a "swap prefetch" patch, which allows processes to respond quickly after the operating system has been idle for some time and their working sets have been swapped out.^[7] Many of his experimental "-ck" patches, such as his prefetching and scheduling code, did not get merged with the official Linux kernel.

On July 24, 2007, Kolivas announced that he would cease developing for the Linux kernel. The reasons he gave are that desktop performance on Linux is getting too little attention and that "Linux is burdened with 'enterprise crap' that makes it run poorly on desktop PCs" ^[8]. Enterprise crap refers to kernel development targeted towards servers.