rock on con kolivas

This xkcd cartoon inspired Con Kolivas to write a new scheduler.

















http://ck.kolivas.org/german_linux_magazine_interview.txt
http://www.linux-magazine.com/Online/News/Con-Kolivas-Introduces-New-BFS-Scheduler

Con Kolivas Introduces New BFS Scheduler
Sep 02, 2009

After two years deep into Linux, the Australian Con Kolivas has emerged with a new scheduler that above all should provide significantly better performance on dual and quad processors.


The Australian developer Con Kolivas

Whoever hasn't recently had a good enough reason to translate the kernel should take a look at the new patch from Con Kolivas. His Brain Fuck Scheduler (BFS) should, after compiling on a quad system, demonstrate better performance than the current Completely Fair Scheduler (CFS) from Ingo Molnar.

As Kolivas writes in his FAQ to the BFS, the performance improvement contrasts with how the current schedulers work with the CPUs:

"For years we've been doing our workloads on Linux to have more work than we had CPUs because we thought that the 'jobservers' were limited in their ability to utilise the CPUs effectively (so we did make -j6 or more on a quad core machine for example). This scheduler proves that the jobservers weren't at fault at all, because make -j4 on a quad core machine with BFS is faster than *any* choice of job numbers on CFS."

The name Kolivas gave to his scheduler obviously meant to be provocative. On the one hand he was determined that it was possible to write a good scheduler using simple means and straightforward thinking. On the other he wanted to point out that it was totally unsatisfactory to have a scheduler support 4096 processors but be incapable of successfully running a Flash video on an average system.




Kolivas nevertheless doubts that his newest scheduler will ever be accepted into the official Linux kernel, even though it can run faster on systems with up to 16 CPUs than any previous scheduler. It simply doesn't scale to 4096 processors nor does it work satisfactorily on non-uniform memory access (NUMA) systems.

The BFS patch along with benchmark diagrams and other details are on ck.kolivas.org. Why Kolivas turned his back on kernel development two years ago was revealed in an interview with Linux Magazine, a transcript of which also appears at the same website.