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
Permalink for comment
To read all comments associated with this story, please click here.
RE: Anonymous (IP:
by Anonymous on Sat 9th Apr 2005 14:56 UTC

How do you have a lockless path in an SMP environment and still share resources?

There are a lot of lockless algorithms and data structures.

The schemes preferred the Linux kernel where scalability is important are firstly per-CPU data structures where possible, then things like RCU and seqence/generation counting with read retry, atomic modification of data, etc.

Do you mean they focus on minimizing lock operations by increasing the ammount of code covered by a single locked segment?

No. In Linux, you lock data, not code. And where locks are used, the focus is on having as narrow a hold width as possible.

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.

Actually FreeBSD developers used to brag about having a working SMP implementation before Linux, which I think may have been true - if not then it would have been very close, definitely not "a lot longer".

And it's not about giving it a chance or not. It simply currently does not have a good SMP implementation.