More fuel on the BFS vs. CFS fire

http://thread.gmane.org/gmane.linux.kernel/889444

by DarkShikari • 17 years ago

27 5 17 years ago

thread.gmane.org

ars2• 17 years ago

Background:

This is about the choice of CPU scheduler in the linux kernel.

CFS: Completely Fair Scheduling, current default.

BFS: Brain Fuck Scheduler, written by the infamous Con Kolivas, see http://news.ycombinator.com/item?id=799147

asyazwan• 17 years ago

Is that name serious..?

EDIT: I know a language named similar but that's more like a for-fun project, not a serious one to the extent of replacing existing solutions

viraptor2• 17 years ago

"fuel"? It's the first (that I've seen) well described, reproducible test that includes a howto for retesting in this debate... Whether someone improves BFS (cpu jumping) or CFS (general performance) because of this post, we win. Great!

Edit: And that's what happened (more or less) - in the first response:

2.6.31-bfs221-smp - 408.38 fps

2.6.32-tip-smp NO_NEXT_BUDDY NO_LB_BIAS - 418.07 fps

ars2• 17 years ago

It's not the first, there is also: http://lwn.net/Articles/351058/

But, I believe, that test suffers from one fatal flaw: Hyperthreading was enabled, and as far as I know BFS does not support hyperthreading. (Support means: know that that the two CPUs are really the same, rather than treat them as if they were two different physical CPUs.)

viraptor2• 17 years ago

Ah yeah - sorry - I'm just deliberately ignoring the "official" benchmarks from Ingo and Con... At least until one of them publishes a benchmark that shows their own solution loses in some scenario ;)

More fuel on the BFS vs. CFS fire

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