At 09:28, 19990811, Scott Hess wrote:
>At one point, I was VERY concerned about FreeBSD using userland threads and
>Linux using lightweight tasks. Handling I/O blocking between tasks is a
>well-understood problem, and I wondered if seperate tasks would allow for
>better throughput than userland threads. At least with FreeBSD3.1, I have
>no evidence of this being a problem. I still would be more comfortable if I
>had the option of using kernel threads, but they're not there, yet.
When you say, "they're not there, yet", do you mean that kernel
threads are not available in FreeBSD, or that they're not at a
level of stability/performance that you'd be comfortable with?
Because I can assure you that they're available, and with a
recent FreeBSD (3.2) the stability is excellent and the performance
is very good. I've been using kernel threads with FreeBSD since
early this year with not a single crash, lockup, or problem.
There are some performance issues when using FreeBSD's kernel
threads and SMP, because right now a large portion of the kernel
has to be locked. The developers are working on bringing the
locks further into the kernel, so that multiple processes can be
working in the kernel at the same time. But if you're using a
single-processor machine, FreeBSD kernel threads work very well.
There's no need to use MIT-pthreads on FreeBSD.
Tim
P.S. My comment about Linux users in an earlier post was meant
as a blatant poke at myself and anyone else who defends one or
the other without regard to the facts. I hope it was interpreted
that way, and not as a genuine description of anything.
http://www.userfriendly.org/cartoons/archives/99aug/19990804.html
