[erlang-patches] : : More about SCTP and R12B-5

Per Hedeland <>
Sat Nov 8 13:15:01 CET 2008


Raimo Niskanen <> wrote:
>> 
>> >I am an OpenBSD fan myself, and we have had issues with
>> >FreeBSD regarding kernel poll so it has been a while
>> >when FreeBSD has been uninteresting as an ErlangOTP
>> >platform.
>> 
>> Uh, "issues regarding kernel poll" => "uninteresting as an ErlangOTP
>> platform" is a pretty huge leap - there are "a few" Erlang applications
>> that aren't dependant on being able to have thousands of file
>> descriptors open with good performance. Erlang has always worked fine on
>> *BSD IMHO.
>
>My memory failed me. It was a severe problem with writev(),
>and has been fixed for quite a while, but there was a 
>long perion in time Erlang did not work fine on FreeBSD.

Actually I think you were more correct the first time:-) - AFAIK, the
problem was with the combination of writev and kqueue (and pipes), see
e.g.
http://www.erlang.org/pipermail/erlang-questions/2007-April/026055.html
(I have no idea whether it is fixed btw).

Given that writev was introduced by the "original" BSD more than 25
years ago and is used all over the place in current *BSD (and in the
Erlang runtime), while kqueue (the "*BSD version" of "kernel poll") is a
relative newcomer and arguably only needed in "unusual" cases, I would
say that this has to be qualified as a problem with kqueue, not writev.
And again I'll claim that the lack of kernel poll is essentially
uninteresting for many if not most Erlang applications.

>Not a requirement. But since it sometimes is hard to 
>ensure "trustworthy" and it also is easy to make silly
>mistakes when applying the patch; having daily builds
>sure facilitates trying a patch, and maintaining it.

Very reasonable. So I assume that Jimmy's patches, done against current
Erlang/OTP code, from someone who has been the tireless maintainer of
the Erlang FreeBSD port for more than 7 years (the ports *are* built
daily at freebsd.org btw), will be applied ASAP.:-)

--Per



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