Linked by Eugenia Loli on Thu 7th Apr 2005 02:04 UTC, submitted by David Rhodus
BSD and Darwin derivatives After many months of work DragonFly is about to release version 1.2 of its BSD based operating system. The first release candidate version can be download from dfly-20050406-pre1.2.iso.gz
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Re: By Anonymous (IP: ---.dyn.iinet.net.au)
by Anonymous on Fri 8th Apr 2005 16:54 UTC

>FreeBSD has very few lockless paths. Their scheduler
>doesn't even use per-cpu queues AFAIK. Their
>synchronisation primitives are mainly mutex oriented.

How do you have a lockless path in an SMP environment and still share resources? Do you mean they focus on minimizing lock operations by increasing the ammount of code covered by a single locked segment? In this case, you inhibit the option for preemption which incurs latency. There is always a trade off. Lunix has been working on SMP a lot longer than FreeBSD. Give it a chance.

FreeBSD's ULE scheduler has per-cpu queues which is not default for stability reasons. Linux didn't have one either until 2.6 right?

>In many respects Linux is closer to Dragonfly than it is to
>FreeBSD.

A lot of what drangonfly gains is via the microkernel-like lwkt messaging API. What is it that linux employs that makes it similar in this respect?