Questions on the scheduler

Kris Kennaway kris at
Sat Sep 29 09:10:48 PDT 2007

RW wrote:

> The FreeBSD response was to make the kernel more SMP friendly with
> finer-grained locking, and to bring-in the ULE scheduler. Dragonfly BSD
> was a fork off 4.x by people who thought a more radical kernel rewrite
> was needed. Their kernel avoids a lot of the locking problems by using
> message queues.

Just to clarify, that was the theory and intention behind Dragonfly, but 
in practise they have yet to achieve it after 4 years and any benefits 
of their ideas remain unproven.  Basically they have achieved no 
performance gains on SMP and have effectively abandoned working on it.


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